- Author: Omnia M Samra-Latif, MD; Chief Editor: Richard Scott Lucidi, MD, FACOG more...
A patient's choice of contraceptive method involves factors such as efficacy, safety, noncontraceptive benefits, cost, and personal considerations.
Contraceptive techniques based on periodic abstinence include the following:
Natural family planning
Natural family planning is one of the most widely used methods of fertility regulation, particularly for persons whose religious or cultural beliefs do not permit devices or drugs for contraception. This technique involves periodic abstinence, with couples attempting to avoid intercourse during a woman's fertile period, which is around the time of ovulation.
These contraceptives include the following:
Male condom - One of the most popular mechanical barriers and, among all of the barrier methods, the one that provides the most effective protection of the genital tract from sexually transmitted diseases (STDs)
Diaphragm - Prevents pregnancy by acting as a barrier to the passage of semen into the cervix
Cervical cap - Acts as a mechanical barrier to sperm migration into the cervical canal and as a chemical agent with the use of spermicide
Spermicidal agent - Prevents sperm from entering the cervical os by attacking the sperm's flagella and body, reducing their mobility, and disrupting their fructolytic activity, thereby inhibiting their nourishment
Hormonal means of contraception include the following:
Implants - The mechanism of action is a combination of suppression of the luteinizing hormone (LH) surge, suppression of ovulation, development of viscous and scant cervical mucus to deter sperm penetration, and prevention of endometrial growth and development
Injectable depomedroxyprogesterone acetate - Acts by inhibiting ovulation with the suppression of follicle-stimulating hormone (FSH) and LH levels and by eliminating the LH surge
Progestin-only oral contraceptives - Mechanisms of action include (1) suppression of ovulation; (2) a variable dampening effect on the midcycle peaks of LH and FSH; (3) an increase in cervical mucus viscosity; (4) a reduction in the number and size of endometrial glands; and (5) a reduction in cilia motility in the fallopian tube
Combination oral contraceptives - Prevention of ovulation is considered the dominant mechanism of action, with the combination of the 2 steroids creating a synergistic effect that greatly increases their antigonadotropic and ovulation-inhibitory effects; these contraceptives also alter the consistency of cervical mucus, affect the endometrial lining, and alter tubal transport
91-day combination oral contraceptives - Reduce the number of menstrual cycles per year
Combination patch contraceptive - Releases estrogen and progesterone directly into the skin
Contraceptive vaginal ring - Hormones are absorbed directly by the reproductive organs
Intrauterine devices (IUDs) include the following:
Copper T380 - T-shaped, polyethylene IUD with fine copper wire wrapped around the vertical stem
Mirena - T-shaped, polyethylene IUD with a reservoir that contains levonorgestrel, a progesterone
Skyla - T-shaped, polyethylene IUD designed to prevent pregnancy for 3 years, during which time it releases a diminishing dosage of levonorgestrel
Female sterilization prevents fertilization by interrupting the fallopian tubes. It can be performed surgically in the postpartum period with a small, transverse infraumbilical incision or during the interval period. Sterilization during the interval period can be performed with laparoscopy, laparotomy, or colpotomy. The methods of fallopian tube sterilization include occlusion with Falope rings, clips, or bands; segmental destruction with electrocoagulation; or suture ligation with partial salpingectomy.
A newer sterilization technique, the Essure system, does not require surgical incisions and can be performed with the patient under local anesthesia. Using hysteroscopy, a microinsert is placed directly into the fallopian tubes.
Vasectomy involves incision of the scrotal sac, transection of the vas deferens, and occlusion of both severed ends by suture ligation or fulguration.
Emergency postcoital contraception
A variety of emergency contraception methods have been described, including the following:
Emergency contraceptive pills (ECP) (eg, Plan B One-Step, an enteric-coated levonorgestrel ECP that dissolves and is absorbed in the intestine)
Copper T380 IUD
Minipill emergency contraception method (MECM)
The practice of contraception is as old as human existence. For centuries, humans have relied on their imagination to avoid pregnancy. Ancient writings noted on the Kahun papyrus dating to 1850 BCE refer to contraceptive techniques using a vaginal pessary of crocodile dung and fermented dough, which most likely created a hostile environment for sperm. The Kahun papyrus also refers to vaginal plugs of gum, honey, and acacia. During the early second century in Rome, Soranus of Ephesus created a highly acidic concoction of fruits, nuts, and wool that was placed at the cervical os to create a spermicidal barrier.
Today, the voluntary control of fertility is of paramount importance to modern society. From a global perspective, countries currently face the crisis of rapid population growth that has begun to threaten human survival. At the present rate, the population of the world will double in 40 years; in several of the more socioeconomically disadvantaged countries, populations will double in less than 20 years.
On a smaller scale, effective control of reproduction can be essential to a woman's ability to achieve her individual goals and to contribute to her sense of well-being. A patient's choice of contraceptive method involves factors such as efficacy, safety, noncontraceptive benefits, cost, and personal considerations. This article addresses the predominant modes of contraception used in the United States, along with the safety, efficacy, advantages, disadvantages, and noncontraceptive benefits of each.
An oral contraceptives dispenser is depicted below.
In June 2013, the Centers for Disease Control and Prevention (CDC) issued selected practice recommendations for contraceptive use in the United States, covering issues such as the initiation of contraception, follow-up, and possible problems, including missed pills and unscheduled bleeding. Highlights of the guidelines, which are adapted from the World Health Organization’s recommendations, include the following:
No laboratory testing is necessary before contraception is initiated
No physical examination other than a blood pressure check is needed before initiating combined hormonal contraception
Cervical cancer screening is not needed before intrauterine device (IUD) placement
IUD removal is not necessary if a woman develops pelvic inflammatory disease; antibiotic treatment is sufficient
Also, see the patient education articles Birth Control Overview, Birth Control Barrier Methods, How to Use a Condom, Vasectomy, Tubal Sterilization, Birth Control Medications (Contraceptives), Birth Control Hormonal Methods, Birth Control Intrauterine Devices (IUDs), and EmergencyContraception.
Coitus interruptus involves withdrawal of the entire penis from the vagina before ejaculation. Fertilization is prevented by lack of contact between spermatozoa and the ovum. This method of contraception remains a significant means of fertility control in the developing world.
Effectiveness depends largely on the man's capability to withdraw prior to ejaculation. The failure rate is estimated to be approximately 4% in the first year of perfect use. In typical use, the rate is approximately 19% during the first year of use.
Advantages include immediate availability, no devices, no cost, no chemical involvement, and a theoretical reduced risk of transmission of sexually transmitted diseases (STDs).
The probability of pregnancy is high with incorrect or inconsistent use.
Elevated prolactin levels and a reduction of gonadotropin-releasing hormone from the hypothalamus during lactation suppress ovulation. This leads to a reduction in luteinizing hormone (LH) release and inhibition of follicular maturation. The duration of this suppression varies and is influenced by the frequency and duration of breastfeeding and the length of time since birth. Mothers only need to use breastfeeding to be successful; however, as soon as the first menses occurs, she must begin to use another method of birth control to avoid pregnancy.
The perfect-use failure rate within the first 6 months is 0.5%. The typical-use failure rate within the first 6 months is 2%.
Involution of the uterus occurs more rapidly. Menses are suppressed. This method can be used immediately after childbirth. This method facilitates postpartum weight loss.
Return to fertility is uncertain. Frequent breastfeeding may be inconvenient. This method should not be used if the mother has human immunodeficiency virus (HIV) infection.
Natural Family Planning
Natural family planning is one of the most widely used methods of fertility regulation, particularly for those whose religious or cultural beliefs do not permit devices or drugs for contraception. This method involves periodic abstinence, with couples attempting to avoid intercourse during a woman's fertile period, which is around the time of ovulation. Techniques to determine the fertile period include the calendar method, cervical mucus method, or the symptothermal method.
The calendar method is based on 3 assumptions as follows: (1) A human ovum is capable of fertilization only for approximately 24 hours after ovulation, (2) spermatozoa can retain their fertilizing ability for only 48 hours after coitus, and (3) ovulation usually occurs 12-16 days before the onset of the subsequent menses. The menses is recorded for 6 cycles to approximate the fertile period. The earliest day of the fertile period is determined by the number of days in the shortest menstrual cycle subtracted by 18. The latest day of the fertile period is calculated by the number of days in the longest cycle subtracted by 11.
With the cervical mucus method, the woman attempts to predict her fertile period by quantifying the cervical mucus with her fingers. Under the influence of estrogen, the mucus increases in quantity and becomes progressively more elastic and copious until a peak day is reached. This is followed by scant and dry mucus, secondary to the influence of progesterone, which remains until the onset of the next menses. Intercourse is allowed 4 days after the maximal cervical mucus until menstruation.
The symptothermal method predicts the first day of abstinence by using either the calendar method or the first day mucus is detected, whichever is noted first. The end of the fertile period is predicted by measuring basal body temperature. The basal body temperature of a woman is relatively low during the follicular phase and rises in the luteal phase of the menstrual cycle in response to the thermogenic effect of progesterone. The rise in temperature can vary from 0.2-0.5°C. The elevated temperatures begin 1-2 days after ovulation and correspond to the rising level of progesterone. Intercourse can resume 3 days after the temperature rise.
The failure rate in typical use is estimated to be approximately 25%.
No adverse effects from hormones occur. This may be the only method acceptable to couples for cultural or religious reasons. Immediate return of fertility occurs with cessation of use.
This is most suitable for women with regular and predictable cycles. Complete abstinence is necessary during the fertile period unless backup contraception is used. This method requires discipline. The method is not effective with improper use. The failure rate is relatively high. This method does not protect against STDs.
The condom consists of a thin sheath placed over the glans and the shaft of the penis that is applied before any vaginal insertion. It is one of the most popular mechanical barriers. Among all of the barrier methods, the condom provides the most effective protection of the genital tract from STDs. Its usage has increased from 13.2-18.9% among all women of reproductive age because of the concern regarding the acquisition of HIV and STDs. It prevents pregnancy by acting as a barrier to the passage of semen into the vagina.
In a November 2013 policy statement, the American Academy of Pediatrics (AAP) provided updated recommendations for improving the use of condoms among adolescents. These include the following:
Adolescents should be encouraged to abstain from sexual intercourse or postpone future sexual relationships
Pediatricians should play a role in educating adolescents and their parents about responsible sexual activity and encouraging the correct use of condoms among adolescents who are sexually active
Health education programs for K-12 children should provide education and counseling about sexual activity and be integrated into collaborative, community-based condom-availability programs
School-based condom distribution should be considered a valid means of obtaining contraception
Pediatricians and other clinicians should help to make condoms more available to adolescents by providing condoms directly and by encouraging better condom availability in the community
Pediatricians should raise awareness that the onset and frequency of sexual activity among adolescents are not increased by better access to condoms
The failure rate of condoms in couples that use them consistently and correctly during the first year of use is estimated to be approximately 3%. However, the true failure rate is estimated to be approximately 14% during the first year of typical use. This marked difference of failure rates reflects errors in usage. Common errors with condoms usage include failure to use condoms with every act of intercourse and throughout intercourse, improper lubricant use with latex condoms (eg, oil-based lubricants), incorrect placement of the condom on the penis, and poor withdrawal technique.
Condoms are readily available and are usually inexpensive. This method involves the male partner in the contraceptive choice. Condoms are effective against both pregnancy and STDs.
Condoms possibly decrease enjoyment of sex. Some users may have a latex allergy. Condom breakage and slippage decrease effectiveness. Oil-based lubricants may damage the condom.
The Reality female condom is a polyurethane sheath intended for one-time use, similar to the male condom. It contains 2 flexible rings and measures 7.8 cm in diameter and 17 cm long (see the image below). The ring at the closed end of the sheath serves as an insertion mechanism and internal anchor that is placed inside the vaginal canal. The other ring forms the external patent edge of the device and remains outside of the canal after insertion.
The female condom prevents pregnancy by acting as a barrier to the passage of semen into the vagina. Simultaneous use of both the female and male condom is not recommended because they may adhere to each other, leading to slippage or displacement of either device.
Efficacy trials are limited. Initial trials have demonstrated a pregnancy rate of 15% in 6 months. Less than 1% of women in the United States use this method of contraception.
The female condom provides some protection to the labia and the base of the penis during intercourse. The sheath is coated on the inside with a silicone-based lubricant. It does not deteriorate with oil-based lubricants. It can be inserted as long as 8 hours before intercourse.
The lubricant does not contain spermicide. The device is difficult to place in the vagina. The inner ring may cause discomfort. Some users consider the female condom cumbersome. The female condom may cause a urinary tract infection if left in vagina for a prolonged period.
The diaphragm is a shallow latex cup with a spring mechanism in its rim to hold it in place in the vagina (see the image below). Diaphragms are manufactured in various diameters. A pelvic examination and measurement of the diagonal length of the vaginal canal determines the correct diaphragm size. It is inserted before intercourse so that the posterior rim fits into the posterior fornix and the anterior rim is placed behind the pubic bone. Spermicidal cream or jelly is applied to the inside of the dome, which then covers the cervix.
It prevents pregnancy by acting as a barrier to the passage of semen into the cervix. Once in position, the diaphragm provides effective contraception for 6 hours. If a longer interval has elapsed without removal of the diaphragm, fresh spermicide is added with an applicator. After intercourse, the diaphragm must be left in place for at least 6 hours.
Effectiveness of the diaphragm depends on the age of the user, experience with its use, continuity of use, and the use of spermicide. The typical-use failure rate within the first year is estimated to be 20%.
The diaphragm does not entail hormonal usage. Contraception is controlled by the woman. The diaphragm may be placed by the woman in anticipation of intercourse.
Prolonged use during multiple acts of intercourse may increase the risk of urinary tract infections. Usage for longer than 24 hours is not recommended due to the possible risk of toxic shock syndrome (TSS). The diaphragm requires professional fitting. Poorly fitted diaphragms may cause vaginal erosions. Diaphragms have a high failure rate. Use of a diaphragm requires brief, formal training. The diaphragm may develop an odor if not properly cleansed.
The cervical cap is a cup-shaped latex device that fits over the base of the cervix. A groove along the inner circumference of the rim improves the seal between the inner rim of the cap and the base of the cervix. The cap must be filled one third full with spermicide prior to insertion. It is inserted as long as 8 hours before coitus and can be left in place for as long as 48 hours.
A cervical cap acts as both a mechanical barrier to sperm migration into the cervical canal and as a chemical agent with the use of spermicide.
Effectiveness depends on the parity of women due to the shape of the cervical os. With perfect use in the first year, the failure rate for nulliparous women is 9%, as opposed to 20% in parous women. With typical use within the first year, the failure rate is 20% in nulliparous women and 40% in parous women.
It provides continuous contraceptive protection for its duration of use regardless of the number of intercourse acts. Unlike with the diaphragm, additional spermicide is not necessary for repeated intercourse. The cervical cap does not involve ongoing use of hormones.
Cervical erosion may lead to vaginal spotting. The cervical cap is associated with a theoretical risk of TSS if it is left in place longer than the prescribed period. The cervical cap requires professional fitting and training for use. Severe obesity may make placement difficult. It has a relatively high failure rate. Candidates must have history of normal results on Papanicolaou (Pap) tests.
Vaginal spermicides consist of a base combined with either nonoxynol-9 or octoxynol. The actual spermicidal agent consists of a surfactant that destroys the sperm cell membrane. Bases include vaginal foams, suppositories, jellies, films, foaming tablets, and creams. These must be inserted into the vagina prior to each coital act. Use of spermicidal agents also reduces the risk of infection by both viral and bacterial organisms that cause STDs; however, clinical data on their efficacy for preventing the transmission of HIV are limited. Nonoxynol-9 is toxic to the lactobacilli that are part of the normal vaginal flora. Adverse effects include increased vaginal colonization with the bacteria Escherichia coli, which may predispose to bacteriuria after intercourse.
Spermicides prevent sperm from entering the cervical os by attacking the sperm's flagella and body, reducing their mobility, and disrupting their fructolytic activity, thereby inhibiting their nourishment.
The perfect-use failure rate within the first year is 6%. The typical-use failure rate within the first year is 26%.
The lubrication provided by spermicides may heighten satisfaction in both partners. Another advantage is the ease of application. Either partner can purchase and apply spermicide because it is easily accessible, available over the counter, and inexpensive. Applying spermicide requires minimal patient education. It augments contraceptive efficacy of the cervical cap and diaphragm. Spermicides produce no adverse systemic effects.
Spermicides provide minimal protection from STDs. Insertion may be uncomfortable for some couples. Vaginal irritation is possible, and spermicides may cause an allergic reaction.
The US Food and Drug Administration (FDA) approved the contraceptive use of levonorgestrel implants (Norplant) in 1990. This method consists of 6 silicone rubber rods, each measuring 34 mm long and 2.4 mm in diameter and each containing 36 mg of levonorgestrel. The implant releases approximately 80 mcg of levonorgestrel per 24 hours during the first year of use, achieving effective serum concentrations of 0.4-0.5 ng/mL within the first 24 hours. The rate of release decreases to an average of 30 mcg/d in the latter years of use. Release of the progestational agent by diffusion provides effective contraception for 5 years. Contraceptive protection begins within 24 hours of insertion if inserted during the first week of the menstrual cycle. The rods are inserted subcutaneously, usually in the woman's upper arm, where they are visible under the skin and can be easily palpated.[2, 3]
The mechanism of action is a combination of suppression of the LH surge, suppression of ovulation, development of viscous and scant cervical mucus to deter sperm penetration, and prevention of endometrial growth and development.
The contraceptive efficacy of the method is equivalent to that of surgical sterilization. Overall, pregnancy rates increase from 0.2% in the first year to 1.1% by the fifth year.
The longevity of its effectiveness is an advantage. Its effectiveness is not related to its use in regards to coitus. Exogenous estrogen is absent. Prompt return to the previous state of fertility occurs upon removal. No adverse effect on breast milk production occurs.
A minor surgical procedure is necessary for incision. Difficulty in removal is a disadvantage. Menstrual irregularities are common along with other adverse effects, including headaches, mood changes, hirsutism, galactorrhea, and acne.
Absolute contraindications include active thrombophlebitis or thromboembolic disease, undiagnosed genital bleeding, acute liver disease, benign or malignant liver tumors, known or suspected breast cancer, and a history of idiopathic intracranial hypertension. Relative contraindications include heavy cigarette smoking, a history of ectopic pregnancy, diabetes mellitus, hypercholesterolemia, severe acne, hypertension, and a history of cardiovascular disease, severe vascular or migraine headaches, and severe depression.
Appropriate candidates are women who are postpartum or breastfeeding, women who have difficulty with contraceptive compliance, women in whom pregnancy is contraindicated due to a medical condition, and patients with contraindications to the use of estrogen.
Wyeth-Ayerst Laboratories (Philadelphia, Pa), the maker of the Norplant System, advised health practitioners to inform patients who had the product inserted since October 20, 1999 to use an additional (backup) method of contraception. Laboratory testing showed the product from certain lots may not release enough of the hormone levonorgestrel to deliver effective ongoing contraception. In July 2002, Wyeth Pharmaceuticals then announced that patients who had received the Norplant System and who were using backup contraception may safely stop using backup methods for contraception.
Due to its recall and controversy over use, Wyeth also had announced that it did not plan to resume distribution or marketing of the Norplant System in 2002. The Norplant system had been controversial due to its adverse effects and the company's failure to communicate the risks of adverse effects to the patients. Women alleged that Norplant makers failed to properly and adequately warn them about the severity of adverse effects they may experience, including nausea, headaches, irregular menstrual bleeding, ovarian cysts, weight gain, removal problems, and depression.
Another FDA-approved implant is the 2-rod levonorgestrel system, termed Norplant II or Jadelle. Each rod is 4.4 cm long and contains a cured homogenous mixture of the drug and a polydimethylsiloxane elastomer covered by silicone tubing. Norplant II is approved for 3 years of use but has been shown to be effective for as long as 5 years. After reviewing additional data in 2002, the FDA changed their requirements so as to allow Jadelle to be used for up to 5 years, if it was sold in the United States. The implant has also been approved in Europe for 5 years' use.
Studies have shown Norplant II to have release rates, pregnancy rates, and adverse effect profiles similar to Norplant. At this time, Norplant II is not currently being marketed in the United States. Jadelle is currently available in both developed and developing nations around the world.
Implanon is a single-rod implant that is 4 cm long and 2 mm in diameter. It consists of 68 mg of etonogestrel in an ethylene vinyl acetate copolymer core. Etonogestrel is a biologically active metabolite of desogestrel. Desogestrel is significantly more potent than levonorgestrel; a serum concentration of 0.09 ng/mL can inhibit ovulation in most women. Serum concentrations are adequate for contraception coverage for approximately 3 years. In more than 10 different studies using 4000 women-years of use, no pregnancies have been demonstrated. Effectiveness in women who are overweight has not been defined. Women who weighed more than 130% of their ideal body weight were not studied; because serum concentrations are inversely related to body weight and decrease with time after insertion, etonogestrel implant may be less effective in women who are overweight.
Compared with the Norplant system, Implanon is associated with a higher frequency of amenorrhea and oligomenorrhea, a decrease in the prevalence of frequent and prolonged bleeding, and a decrease in the frequency of adverse effects such as weight gain, headache, and acne. When the rod is removed, the return to fertility is rapid, with the return of ovulation within 3 weeks. Implanon was approved for use in the United Kingdom in 1999 and has recently been approved in the United States. Knowledge of the long-term effects and overall safety data are limited at this point. However, Implanon is not associated with loss of bone mineral density (BMD).
In one study that compared the BMD of patients using Implanon with those using intrauterine devices (IUDs), no decrease was noted in the BMD of either group over a 2-year period. Preservation of BMD may, in part, be associated with the observation that women who use Implanon appear to have a greater circulating estradiol concentration than women who use depomedroxyprogesterone acetate (DMPA).
Injectable Depomedroxyprogesterone Acetate
DMPA is a suspension of microcrystals of a synthetic progestin that is injected intramuscularly. Pharmacologically active levels are achieved within 24 hours after injection, and serum concentrations of 1 ng/mL are maintained for 3 months. During the fifth or sixth month after injection, the levels decrease to 0.2 ng/mL, and they become undetectable by 7-9 months after injection.
DMPA acts by the inhibition of ovulation with the suppression of follicle-stimulating hormone (FSH) and LH levels and eliminates the LH surge. This results in a relative hypoestrogenic state. Single doses of 150 mg suppress ovulation in most women for as long as 14 weeks. The contraceptive regimen consists of 1 dose every 3 months.
DMPA is an extremely effective contraceptive option. Neither varying weight nor use of concurrent medications has been noted to alter efficacy. Within the first year of use, the failure rate is 0.3%.
DMPA does not produce the serious adverse effects of estrogen, such as thromboembolism. Diminished anemia occurs. Dysmenorrhea is decreased. The risks of endometrial and ovarian cancer are decreased. It contains no estrogen, thus making it suitable for women who cannot or will not take estrogen products. It also is safe for breastfeeding mothers.
Disruption of the menstrual cycle to eventual amenorrhea occurs in 50% of women within the first year. Persistent irregular bleeding can be treated by administering the subsequent dose earlier or by prescribing temporary low-dose estrogen therapy. Because DMPA persists in the body for several months in women who have used it on a long-term basis, it can delay the return to fertility. Approximately 70% of former users desiring pregnancy conceive within 12 months, and 90% of former users conceive within 24 months. Similar to the delay in fertility after discontinuation of DMPA, other adverse effects, such as weight gain, depression, and menstrual irregularities, may continue for as long as 1 year after the last injection.
A study by Bonny and colleagues found that adolescent girls, who gained more than 5% of their baseline weight after 6 months of DMPA use, are at an increased risk for excessive future weight gain. They concluded that weight gain after 6 months can be used to identify those at risk for further weight gain. Counseling can then be instituted for these patients.
The FDA issued a "black-box" warning in November 2004, stating that bone loss from using Depo-Provera "may not be completely reversible" even after stopping the drug. The warning urged women not to use Depo-Provera on a long-term basis unless all other methods were inadequate.
Most users of DMPA are teens at a crucial age for the building of bone density; about 10% of American females aged 15-19 years who use birth control use Depo-Provera, compared with 3% of women in the United States overall.
Studies have contradicted the FDA warning. Women who stopped using DMPA experienced an average bone gain of 1.34% at the hip versus a loss of 0.19% for women who never took the drug. Spine density increased 2.86% for women who stopped using the drug, compared with an increase of 1.32% for nonusers. Furthermore, teens regained their bone density faster than older women using Depo-Provera.
The main limitation, from the patient's point of view, has been the intramuscular (IM) route of injection, which requires an office visit every 12-14 weeks for administration. A subcutaneous version of the drug is now available (depo-subQ provera 104) that delivers a lower dose of medroxyprogesterone acetate (MPA) than does the intramuscular formulation (104 mg vs 150 mg). The subcutaneous route opens the possibility for home self-injections, and the lower dose could decrease suppression of pituitary function and ovarian estradiol production. Further study is needed.
Subcutaneous DMPA, like its intramuscular counterpart, is associated with changes in bone mineral density and also carries a "black box" warning regarding this risk. Studies demonstrate lower decreases in bone mineral density as compared with the intramuscular route and the same reversible effect.
Progestin-Only Oral Contraceptives
Progestin-only oral contraceptives, also known as minipills, are not used widely in the United States. Less than 1% of users of oral contraceptives use them as their sole method of contraception. Candidates for use include women who are breastfeeding and women with contraindications to estrogen use. Two formulations are available, both of which have lower doses of progestin than combined oral contraceptives. One formulation contains 75 mcg of norgestrel. The other has 350 mcg of norethindrone.
Prevention of conception involves a combination of mechanisms similar to, but not as efficacious as, combination oral contraceptives. Mechanisms of action include (1) suppression of ovulation (not uniformly in all cycles); (2) a variable dampening effect on the midcycle peaks of LH and FSH; (3) an increase in cervical mucus viscosity by a reduction in its volume and an alteration of its structure; (4) a reduction in the number and size of endometrial glands, leading to an atrophic endometrium not suitable for ovum implantation; and (5) a reduction in cilia motility in the fallopian tube, thus slowing the rate of ovum transport.
Serum progestin levels peak approximately 2 hours after administration. Within 24 hours, rapid distribution and elimination returns the level to baseline. Greater efficacy is achieved with consistent administration. Failure rates with typical use are estimated to be 7% in the first year of use. However, any variation can increase the failure rate.
Due to the lack of estrogen, evidence of serious complications to which estrogen can contribute (ie, thromboembolism) is minimal. Noncontraceptive benefits include decreased dysmenorrhea, decreased menstrual blood loss, and decreased premenstrual syndrome symptoms. Unlike DMPA, fertility is immediately reestablished after the cessation of progestin-only oral contraceptives.
The most significant disadvantage is the continuous need for compliance with usage. Users need to be counseled on the need for a backup method of contraception if a pill is missed or taken late. A pill is considered late if ingestion occurs 3 hours after the established time of administration. If a pill is missed, it should be taken as soon as possible; the next pill should be taken at the scheduled time. Backup contraception should be used for the next 48 hours. Unscheduled bleeding and spotting are common even with correct use. Other adverse effects include nausea, breast tenderness, headache, and amenorrhea.
Combination Oral Contraceptives
Oral contraceptives have been marketed in the United States since 1962. The dose of sex steroids has declined significantly in the past 40 years. Prior to 1992, the estrogenic component of oral contraceptives consisted of either ethinyl estradiol or mestranol. Today, ethinyl estradiol is used in all preparations containing 35 mcg or less of estrogen in the United States. The progestin component consists of norethindrone, levonorgestrel, norgestrel, norethindrone acetate,ethynodioldiacetate, norgestimate, and desogestrel. The most recent addition to the progestin group is the addition of drospirenone, found in Yasmin birth control pills.
The other major development is the reduction in the dosage of ethinyl estradiol to 20 mcg. The major impetus for this change is to improve the safety and reduce adverse effects. However, few data exist to indicate whether reduction of the estrogen dose is associated with a decreased risk of serious sequelae. These lower doses are associated with a decrease in the incidence of estrogen-related adverse effects, such as weight gain, breast tenderness, and nausea.
Another recent development is the release of a combined oral contraceptive pill to raise folate serum levels. Beyaz contains the same progestin and estrogen contents as Yaz (drospirenone 3 mg/ethinyl estradiol 20 mcg) plus 0.451 mg levomefolate calcium (folic acid metabolite).
In the United States today, more than 30 oral contraceptive formulations are available. Monophasic oral contraceptives have a constant dose of both estrogen and progestin in each of the hormonally active pills. Phasic combinations can alter either or both hormonal components. Use should be initiated either on the first day of the menses or the first Sunday after menses has begun. Most of the formulations have 21 hormonally active pills followed by 7 placebo pills. This facilitates consistent daily pill intake.
A French study found that among women taking combination oral contraceptive pills, those using a tailored regimen (pills taken daily until the occurrence of 3 consecutive days of bleeding, followed by 3 pill-free days) experienced significantly less bleeding than did women using a standard regimen (pills taken daily for 21 days, followed by 7 pill-free days). The pills used contained 30 mcg of ethinyl estradiol and 150 mcg of levonorgestrel.
The randomized, controlled trial evaluated various outcomes from the standard and tailored regimens after 1 year in over 350 women (out of an initial 503) aged 18-45 years. The rate of satisfaction with the regimen and with the bleeding pattern was higher in patients on the standard regimen than in those on the tailored one (94% vs 86% and 87% vs 79%, respectively). Women on the tailored regimen, however, had a higher rate of continuation at 1 year than did those on the standard regimen (82% vs 80%, respectively), as well as a lower median number of bleeding days per month (2.4 days vs 4.9 days, respectively).
Analysis of data from the International Active Surveillance of Women Taking Oral Contraceptives showed higher contraceptive effectiveness for women taking the 24-day oral contraceptive pill regimen containing progestogen with a long half-life, under normal medical conditions.
If a woman misses 1 or 2 pills, she should take 1 tablet as soon as she remembers. She then takes 1 tablet twice daily until coverage of the missed pills is achieved. Women who have missed more than 2 consecutive pills should be advised to use a backup method of contraception simultaneous to finishing up the packet of pills until their next menses.
Prevention of ovulation is considered the dominant mechanism of action. Either estrogen or progesterone alone is capable of inhibiting both FSH and LH sufficiently to prevent ovulation. The combination of the 2 steroids creates a synergistic effect that greatly increases their antigonadotropic and ovulation-inhibitory effects. They also alter the consistency of cervical mucus, affect the endometrial lining, and alter tubal transport.
Failure rates are correlated to individual compliance. Rates range from 0.1% with perfect use to 5% with typical use.
Oral contraceptives are used as treatment for menstrual irregularity because menses is more regular and predictable. In the prevention of ovulation, oral contraceptives can reduce and sometimes eliminate mittelschmerz. Women with anemia secondary to menorrhagia increase their iron stores. Women can manipulate the cycle to avoid menses during certain events, such as vacations or weekends, by extending the number intake days of hormonally active pills or by skipping the placebo pill week. Oral contraceptives prevent benign conditions, such as benign breast disease, pelvic inflammatory disease (PID), and functional cysts. Functional cysts are reduced by the suppression of stimulation of the ovaries by FSH and LH. Ectopic pregnancies are prevented by the cessation of ovulation.
Oral contraceptives are noted to prevent epithelial ovarian and endometrial carcinoma. Studies have noted an approximate 40% reduced risk of malignant and borderline ovarian epithelial cancer. This protection appears to last for at least 15 years following discontinuation of use and increases with duration of use. This protection has not been studied with low-dose oral contraceptives or in women with genetic ovarian cancer syndromes. Use of oral contraceptives is associated with a 50% reduction of risk of endometrial adenocarcinoma. Protection appears to persist for at least 15 years following discontinuation of use.
Adverse effects include nausea, breast tenderness, breakthrough bleeding, amenorrhea, and headaches. Oral contraceptives do not provide protection from STDs. Daily administration is necessary, and inconsistent use may increase the failure rate. A few months of delay of normal ovulatory cycles may occur after discontinuation of oral contraceptives. Women who continue to have amenorrhea after a discontinuation period of 6 months require a full evaluation.
Metabolic effects and safety
See the list below:
Venous thrombosis: The estrogen component of oral contraceptives has the capability of activating the blood clotting mechanism. Use of low-estrogen oral contraceptives is associated with a lower risk of thromboembolism than use of oral contraceptives with higher levels of estrogen. Although use of oral contraceptives is not associated with a detectable hypercoagulable state for most women, users at a greater risk for thromboembolism include women who smoke heavily, women with high or abnormal blood lipids, women with severe diabetes with damage to the arteries, women with consistently elevated blood pressures, and women who are obese.
Hypertension: Oral contraceptives have a dose-related effect on blood pressure. With the older, high-dose pills, as many as 5% of patients could expect to have blood pressure elevations of 140/90 mm Hg or higher. This elevation is believed to be secondary to an estrogen-induced increase in renin substrate in susceptible individuals. Although today's low-dose pills have minimal blood pressure effects, maintaining a surveillance of blood pressure is advisable.
Atherogenesis and stroke: Although androgens and a few of the progestins actually may increase low-density lipoproteins and decrease high-density lipoproteins, past use of oral contraceptives does not increase the risk of cardiovascular disease. Limited preliminary data have demonstrated that oral contraceptive use does not lead to coronary atherosclerosis. In rare cases in which myocardial infarcts have been found, the cause has been noted to be of thrombotic rather than of atherosclerotic etiology. In general, a woman's habits are more significant than the use of oral contraceptives in determining her risk for cardiovascular disease. The patient who is sedentary, is overweight, smokes heavily, is hypertensive, is diabetic, or has hypercholesterolemia is clearly at risk.
Hepatocellular adenoma: These benign liver tumors have been associated with the use of oral contraceptives. Although these tumors are histologically benign, their danger lies in the risk of rupture of the capsule of the liver, leading to extensive bleeding and, possibly, death. With the current low-dose oral contraceptive combination, the risk for liver tumors is much lower.
- The association of oral contraceptive use and breast cancer in young women is controversial. The Collaborative Group on Hormonal Factors in Breast Cancer performed the most comprehensive analysis of breast cancer and oral contraceptive use and reported findings in 1996. This group evaluated original published epidemiological data from more than 20 countries. The results demonstrated that current oral contraceptive users, and those who had used oral contraceptives within the past 1-4 years, had a slightly increased risk of breast cancer. Although these observations support the possibility of a marginally elevated risk, the group noted that the oral contraceptive users had more breast examinations and breast imaging than the nonusers. Thus, although the consensus states that oral contraceptives can lead to breast cancer, the risk is small and the resulting tumors spread less aggressively than usual.
- Current thought is that oral contraceptive use may be a cofactor that can interact with another primary cause to stimulate breast cancer.
- The relationship between oral contraceptive use and cervical cancer is also quite controversial. A weak association may exist between oral contraceptive use and squamous cell cancer of the cervix. Important risk factors include early sexual intercourse and exposure to the human papillomavirus. The overall consensus is that if indeed oral contraceptive use increases the risk of cervical neoplasia, it is a minimal risk. Thus, women who use oral contraceptives should have annual Pap tests.
Contraindications to use include cerebrovascular disease or coronary artery disease; a history of deep vein thrombosis, pulmonary embolism, or congestive heart failure; untreated hypertension; diabetes with vascular complications; estrogen-dependent neoplasia; breast cancer; undiagnosed abnormal vaginal bleeding; known or suspected pregnancy; active liver disease; and age older than 35 years and cigarette smoking.
Lastly, drospirenone has antimineralocorticoid properties. It is contraindicated in patients with kidney or adrenal gland insufficiency or liver problems. Potassium levels should be checked during the first month of use, especially if drospirenone is taken daily with drugs that can increase potassium levels (eg, nonsteroidal anti-inflammatory drugs, ACE inhibitors).
91-Day Combination Oral Contraceptives
Currently on the market, 91-day combination oral contraceptives have touted a reduction in menstrual cycles per year. Seasonale is a 91-day oral contraceptive regimen in which tablets containing the active hormones are taken for 12 weeks (84 d), followed by 1 week (7 d) of placebo tablets. Conventional oral contraceptive use is based on a 28-day regimen (21 d of active tablets followed by 7 d of placebo tablets). Seasonale contains a progestin (levonorgestrel) and an estrogen (ethinyl estradiol), which are active ingredients in already approved oral contraceptives. With the Seasonale dosing regimen, the expected menstrual periods that a woman usually experiences are reduced from once a month to approximately once every 3 months. As with the conventional 28-day regimen, women experience menses while taking placebo tablets.
Although Seasonale users have fewer scheduled menstrual cycles, the data from clinical trials show that many women, especially in the first few cycles of use, had more unplanned bleeding and spotting between the expected menstrual periods than women taking a conventional 28-day cycle of oral contraceptive.
To counteract the unplanned bleeding, a newer version of Seasonale (Seasonique) was developed. This new brand completely eliminates the hormone-free interval. Seasonique also has 84 active pills (30 mcg of ethinyl estradiol and 150 mcg of levonorgestrel) but is followed by 7 more active pills (10 mcg ethinyl estradiol) instead of the traditional placebo. Therefore, no hormone-free weeks occur.
The 2 main advantages to replacing the placebo week with a week of low-dose estrogen are a diminished amount of unplanned bleeding and spotting and fewer or no symptoms (eg, cramping, bloating, headaches) for women who are sensitive to the placebo-week hormone fluctuations (in particular, low estrogen). A study of 1000 sexually active adult women (aged 18-40 y) who used Seasonique for one year found that, for cycles 2-4, the median number of bleeding days on a per-patient month was minimal (< 1 d).
The risks of using Seasonale are similar to the risks of other conventional combination oral contraceptives and include an increased risk of blood clots, heart attack, and stroke. The labeling also carries the warning that cigarette smoking increases the risk of serious adverse cardiovascular effects from the use of combination estrogen-containing and progestin-containing contraceptives. The study cited for Seasonique does not report any unexpected adverse events or thromboembolic events; the risk profile is the same as Seasonale.
In 2009, the makers of Seasonique came out with LoSeasonique. LoSeasonique consists of 84 orange tablets containing 0.1 mg levonorgestrel and 0.02 mg ethinyl estradiol and 7 yellow tablets containing 0.01 mg ethinyl estradiol. The risk profile is similar to its sister products Seasonale and Seasonique; however, the risk of unplanned breakthrough bleeding is increased.
In a clinical trial, over a 12-month period, 209 of the 2185 participants (9.6%) discontinued LoSeasonique, at least in part, due to bleeding and/or spotting. This breakthrough bleeding remained consistent over time, averaging 2-3 days of bleeding and/or spotting per each 91-day cycle. The breakthrough bleeding eventually decreased over successive 91-day cycles.
Another 91-day oral contraceptive, Quartette, was approved by the FDA in 2013. A phase-3 clinical trial found this product, a combination of levonoregestrel and ethinyl estradiol, to be 97% effective for the prevention of pregnancy.
Lybrel is the first FDA-approved oral contraceptive with 365-day combination dosing. It contains a low combined daily dose of the hormones levonorgestrel and ethinyl estradiol (90 mcg and 20 mcg, respectively). It provides women with more hormonal exposure on a yearly basis (13 additional weeks of hormone intake per year) than conventional cyclic oral contraceptives that contain the same strength of synthetic estrogens and similar strength of progestins.
The incidence of pill failure that results in pregnancy is approximately 1-2% per year (1-2 pregnancies per 100 women per year of use) if taken every day as directed. The average failure rate is approximately 5% per year (5 pregnancies per 100 women per year of use), including women who do not always take the pill exactly as directed without missing any pills.
Combination Patch Contraceptive
Available in the United States since 2001, the contraceptive transdermal patch releases estrogen and progesterone directly into the skin (Ortho Evra, Ortho-McNeil Pharmaceutical; Raritan, NJ). Each patch contains a 1-week supply of hormones of both norelgestromin and ethinyl estradiol. It releases a sustained low daily dose of steroids equivalent to the lowest-dose oral contraceptive. In August 2002, the FDA listed a failure rate for the patch of 1 pregnancy per 100 women per year, similar to that of other combination methods. Advantages include greater compliance and decreased adverse effects, such as nausea and vomiting, due to the avoidance of the first-pass effect. However, the patch may cause skin irritation, and, if it is removed unnoticed, such as from showering, this may compromise efficacy. Disadvantages and contraindications are similartothoseofcombinationoralcontraceptives. It may be less effective for women who weigh more than 198 pounds.
Ortho Women's Health, a unit of Ortho-McNeil Pharmaceutical Inc, updated the warnings section of the prescribing information for the Ortho Evra patch after new studies revealed that its pharmacokinetic profile differs from the pharmacokinetic profile for combination oral contraceptives. Findings noted a higher steady state concentration and lower peak concentrations in the patch as compared with combination oral contraceptives. Average concentrations at steady state for ethinyl estradiol are approximately 60% higher in women using Ortho Evra and peak concentrations are approximately 25% lower in women using Ortho Evra.
This led to a "black box" warning from the FDA in November, 2005. This announcement warned about higher exposure to estrogen for women using the weekly patch compared with those taking a daily combination oral contraceptive containing 35 mcg of estrogen. The new bolded warning specifically states that women who use Ortho Evra are exposed to about 60% more total estrogen in the blood than if they were taking a typical combination oral contraceptive containing 35 mcg of estrogen. Again, peak blood levels of estrogen are about 25% lower with Ortho Evra than with combination oral contraceptive. While the estrogen level with the patch remains constant for 1 week until the patch is removed, the peak blood levels with a daily combination oral contraceptive rapidly decline to levels that are lower than the Ortho Evra levels. The increased estrogen exposure may increase the risk of side effects, such as a thromboembolic event.
These data contrast with those of another study, conducted by the Boston Collaborative Drug Surveillance Program, which looked at the risk of heart attack, stroke, and venous thromboembolic events in first-time users of the patch. In this study, published online in the journal Contraception, the authors found that "the risk of nonfatal venous thromboembolic events for the contraceptive patch is similar to the risk for oral contraceptives containing 35 mcg of ethinyl estradiol and norgestimate." In 2006, the FDA announced that it plans to closely watch the conflicting preliminary data on the risk of thrombosis for women who use Ortho Evra compared with those who take a combination oral contraceptive.
Contraceptive Vaginal Ring
The actual design of vaginal rings as a mode of contraception was first developed in the 1970s. The first rings studied were homogenous devices with the steroid mixed uniformly through a polysiloxane matrix. The design was abandoned because of a high initial release of drug with a rapid decrease of drug release thereafter. The vaginal rings can deliver progesterone or progesterone-estrogen combinations. Today, the combination contraceptive vaginal ring is a new form of contraception that was approved by the FDA in October 2001.
NuvaRing, a vaginal contraceptive ring developed by Organon (Roseland, NJ), is a nonbiodegradable, flexible, colorless ring made up of a polymer of ethylene vinyl acetate and magnesium stearate. The outer diameter of the ring is 54 mm and the cross-sectional diameter is 4 mm. The ring contains 11.7 mg of etonogestrel and 2.7 mg of ethinyl estradiol. It releases 120 mcg of etonogestrel and 15 mcg of ethinyl estradiol each day. The hormones are released slowly and are absorbed directly by the reproductive organs.
The ring is used in the same schedule as oral contraceptives, with 3 weeks of ring usage (ring is left in place for 3 wk) and 1 week without to produce a withdrawal bleed. The ring can be inserted any time during the first 5 days of the menstrual cycle. The ring should be placed in the vagina even if the woman has not finished bleeding, and she should use a backup contraceptive method for 7 days. A new ring should be inserted each month. If the ring comes out during the first 3 weeks of use, it should be washed with lukewarm water and replaced. If the ring-free interval is more than 3 hours, a backup contraceptive method should be used for 7 days. The ring should never be left in the vagina for more than 4 weeks. If left in for more than 4 weeks, pregnancy should be excluded before inserting a new ring and a backup contraceptive method should be used for 7 days after inserting a new ring.
Gilliam et al compared satisfaction and adherence to the contraceptive vaginal ring (n=136) with daily low-dose oral contraceptive pill (OCP) (n=137) among college and graduate students. Participants completed daily Internet-based, online diaries during 3 cycles and a final online survey at 3 and 6 months.
The authors found that vaginal ring users were more likely to report perfect use during the 3-month trial period than were OCP users. Participants were equally satisfied with their assigned hormonal contraceptive method. At 6 months, less than 30% of participants were still using their assigned method.
NuvaRing is highly effective because it results in complete suppression of ovulation. The steady release of hormone provides exceptional cycle control. The ring is a very effective reversible method of birth control. With typical use, although no studies have been published, the ring is presumed to be more effective than combination oral contraceptives. For example, with typical usage, 8 of 100 pill users become pregnant; with perfect use of the NuvaRing, fewer than 1 of 100 women becomes pregnant.
Because daily intake is not a component of NuvaRing contraception, because it is easily inserted and removed by the woman herself, and because return of fertility is rapid upon discontinuation, NuvaRing is a highly acceptable method for women and their partners. During the clinical trials, women and their partners reported an acceptability rate of 85%. Because the hormones are absorbed directly into the blood through the vaginal mucosa, the hepatic first-pass metabolism of progestin is prevented. The ring delivers the lowest dose of ethinyl estradiol compared with other combined hormonal contraceptives. Unlike combined oral contraceptives, the adverse effects of nausea and vomiting are avoided with ring use. Because NuvaRing is a recently approved product, results of long-term studies will not be available for some time; however researchers assume that the noncontraceptive advantages associated with the NuvaRing will be similar to those known to be associated with the combination oral contraceptives.
Adverse effects include headaches and vaginal irritation or discharge. The ring may accidentally slip out during intercourse and either the user or the partner may feel the ring during sexual intercourse. Contraindications are similar to those of combined oral contraceptives.
Although the intrauterine device (IUD) is a highly effective method of contraception, it is used by less than 2% of American women of reproductive age. The reason for such a small percentage stems from the withdrawal of FDA-approved IUDs in the 1970s. The Dalkon Shield IUD was withdrawn because of a series of litigations related to septic abortion deaths. The manufacturers withdrew their product because the cost of defending the lawsuits was deemed too expensive.
According to a data brief from the Centers for Disease Control and Prevention's (CDC), there was a nearly 5-fold increase in the use of long-acting reversible contraceptives (LARCs) among US women aged 15 to 44 years from 1.5% in 2002 to 7.2% in 2011-2013.[17, 18]
Until as recently as 2000, the only 2 IUDs available in the United States were the Copper T380 (Pregna International; Mumbai, India) and the progesterone-releasing form, Progestasert (Alza; Mountain View, Calif). In December 2000, the FDA approved another form of IUD, the levonorgestrel intrauterine system termed Mirena (Berlex Laboratories; Montville, NJ). More than 2 million women in Europe have used this form of contraception in the past decade with great success.
The T-shaped progesterone-releasing IUD Progestasert, which is placed into the uterine cavity, is made of ethylene vinyl acetate copolymer. It contains 38 mg of progesterone and minimal amounts of barium sulfate for greater visibility on x-ray films. The vertical limbs are 36 mm long, and the horizontal arms are 32 mm wide. It has a pair of dark-blue double-strings that hang from the lower limb. Approximately 65 mcg/d of progesterone is released from the progesterone form from a reservoir in its stem. This is a sufficient amount of hormone to last for 400 days; therefore, this IUD must be replaced yearly.
The Copper T380 was introduced in 1988. The T-shaped IUD is made of polyethylene with fine copper wire wrapped around the vertical stem. The string is clear or white and hangs from the lower limb of the IUD. This device consists of 308 mg of copper covering portions of its stem and arms. Contraceptive effectiveness continues for 10 years, after which time it must be replaced.
Mirena is similar in shape to the Copper T380 in that it also consists of a small T-shaped frame with a reservoir that contains levonorgestrel, a progesterone. This intrauterine system releases 20 mcg of levonorgestrel per day into the uterine cavity for as long as 5 years. It consists of a polyethylene frame with a cylinder containing a polydimethylsiloxane-levonorgestrel mixture enveloping the vertical arm. The cylinder is coated with a membrane that regulates the release of the hormone. This model is also visible on x-ray films. The Mirena device now has FDA labelling for treating menorrhagia as well.[20, 21]
In January 2013, the FDA approved Skyla, another T-shaped polyethylene device designed to prevent pregnancy for 3 years, during which time it releases a diminishing dosage of levonorgestrel. The Skyla IUD contains 13.5 mg of levonorgestrel that releases at a rate of 14 mcg/day (after 24 days from insertion). The release rate declines after 3 years to 5 mcg/day.
Skyla’s approval is supported by data from a trial involving 1,432 women aged 18-35 years, of which 38.8% (556) had not yet had a child. The pregnancy rate calculated as the Pearl Index (PI) in women aged 18-35 years was the primary efficacy endpoint used to assess contraceptive reliability. The PI estimate for the first year of use, based on the 5 pregnancies that occurred after the onset of treatment and within 7 days after Skyla removal or expulsion, was 0.41 with a 95% upper confidence limit of 0.96. The cumulative 3-year pregnancy rate, based on 10 pregnancies, estimated by the Kaplan-Meier method was 0.9 per 100 women or 0.9%, with a 95% upper confidence limit of 1.7%.
Wildermeersch et al reviewed experience with the frameless, anchored GyneFix copper-releasing intrauterine device. They concluded that the better fit of the device is likely to result in increased use, thereby leading to fewer unintended pregnancies and induced abortions. The study also noted that the standard TCu380A device or Mirena levonorgestrel system should be used with caution unless 3-dimensional sonography indicates that the uterine cavity is sufficiently large.
An IUD causes cervical mucus to be thicker in consistency, thereby altering sperm migration. Uterotubal fluid and motility changes inhibit sperm migration. IUDs also result in endometrial suppression.
One randomized, controlled study investigated whether 6-month use of the levonorgestrel-releasing IUD is typically higher when insertion occurs within 10 minutes of placental delivery as compared with 6-8 weeks postpartum. The results were similar between women who had postplacental IUD placement and those who had scheduled IUD placement 6 weeks postpartum. A similar study was conducted to determine the feasibility of insertion of levonorgestrel at 3 different times postpartum; within 10 min of delivery, 10 min - 48 h after delivery, and ≤6 weeks after delivery. Findings suggest early insertion (≤48 h) may be associated with similar utilization at 6 months when compared to placement after 6 weeks.
An investigator-blinded study showed that mid-cycle cervical mucus of those using levonorgestrel intrauterine system, was of poor quality and also prevented endocervical sperm transport in vitro.
The failure rate is 2% with Progestasert (the progesterone form), 0.6% with the Copper T380, and of 0.1 % with Mirena. The percent of women who continue to use these forms of contraception is high after 1 year of use, 81% and 78% with Progestasert and Copper T380, respectively.
IUDs produce no adverse systemic effects. Ectopic pregnancies are reduced overall; however, the ratio of extrauterine to intrauterine pregnancy is increased if conception does occur. Menstrual blood loss and dysmenorrhea are decreased with Progestasert. Twenty percent of women experience amenorrhea with Mirena.
IUDs are associated with a risk of uterine perforation at the time of insertion. Increased dysmenorrhea occurs with the Copper T380. Increased menstrual blood loss occurs in the first few cycles with use of the Copper T380 and Mirena IUDs. Whether IUDs increase the risk of PID is controversial. IUDs have none of the potential noncontraceptive benefits of hormonal contraceptives. IUDs may be expelled unnoticed, and they do not protect against STDs.
Ectopic pregnancies are half as likely in IUD users as they are in women using no birth control. Ectopic pregnancies are more likely in women who use Progestasert than the Copper T380; however, the overall risk still remains less than for women who do not use birth control. Of those using Progestasert who become pregnant, approximately half of the pregnancies are ectopic. However, to reiterate, the risk of ectopic pregnancy is much less than it is in women who do not use any contraception.
Contraindications include a history of previous PID in the past year or active PID, an abnormal or distorted uterine cavity, undiagnosed genital bleeding, uterine or cervical malignancy, a history of ectopic pregnancy, increased susceptibility to infection (eg, those with leukemia, diabetes, valvular heart disease, or AIDS), Wilson disease, known or suspected pregnancy, a history of genital actinomyces, and active cervical or endometrial infections.
Sterilization is considered an elective permanent method of contraception. Although both female and male sterilization procedures can be reversed surgically, the surgery is technically more difficult than the original procedure and may not be successful. In regard to reversal of sterilization, success is noted to be greater with tubal reanastomosis than with reanastomosis of the vas deferens.
Approximately 1 million American women are sterilized either by surgery on the fallopian tubes or by hysterectomy each year. Female sterilization prevents fertilization by interrupting the fallopian tubes.
Sterilization can be performed surgically in the postpartum period with a small transverse infraumbilical incision or during the interval period. Sterilization during the interval period can be performed with laparoscopy, laparotomy, or colpotomy. The methods of fallopian tube sterilization include occlusion with Falope rings, clips, or bands; segmental destruction with electrocoagulation; or suture ligation with partial salpingectomy.
The latest form of female permanent sterilization is the Essure system. This form of sterilization prevents fertilization by interrupting the fallopian tubes; however, the Essure system does not require surgical incisions and can be performed with the patient under local anesthesia. It is performed hysteroscopically, and a microinsert is placed directly into the fallopian tubes. During the first 3 months after the procedure, the fallopian tube and the microinsert create a tissue barrier that prevents sperm from reaching the egg. After the 3-month period, patients must undergo a hysterosalpingogram to ensure placement.
The United States Collaborative Review of Sterilization has examined the failure rate of female sterilization. Rates vary according to the procedure performed. The cumulative 10-year failure rate with each method of tubal ligation is as follows: spring clip method, 3.7%; bipolar coagulation, 2.5%; interval partial salpingectomy, 2%; silicone rubber bands, 2%; and postpartum salpingectomy, 0.8%.
The Essure procedure has undergone clinical testing in the United States, Europe, and Australia. Data from preliminary clinical testing demonstrate that the Essure system was 99.8% effective in preventing pregnancy after 2 years of follow-up. However, approximately 1 of 7 women in the Essure clinical studies did not achieve successful placement of both microinserts during the first placement procedure. Some of these women chose to undergo a second placement procedure, achieved successful placement of both microinserts during the second procedure, and subsequently were able to rely on Essure for contraception. Of women who relied on Essure, 98% rated their long-term satisfaction with Essure as "good" to "excellent."
Female sterilization does not involve hormones. It is a permanent form of contraception. No data indicate that change in libido, menstrual cycle, or lactation occurs. Female sterilization is usually a same-day procedure.
Female sterilization is a procedure that involves general or regional anesthesia. Patients who undergo the Essure system procedure require a backup method of contraception for the first 3 months. It is permanent contraception, and patients may regret the decision later, especially women younger than 30 years. Regret is difficult to measure because it encompasses a complex spectrum of feelings that can change over time. This helps explain that while some studies have reported "regret" in 26% of women, less than 20% seek reversal and less than 10% actually undergo the reversal procedure.
If the Essure microinserts must be removed for any reason, major surgery is necessary, requiring an abdominal incision and, most likely, general anesthesia.
No data are available on the safety or effectiveness of in vitro fertilization after the Essure procedure has been performed. Sterilization does not protect the patient from STDs. Sterilization causes short-term discomfort, and it involves all the risks of surgery.
Vasectomy involves incision of the scrotal sac, transection of the vas deferens, and occlusion of both severed ends by suture ligation or fulguration. The procedure is usually performed with the patient under local anesthesia in an outpatient setting. Complications include hematoma formation and sperm granulomas. Spontaneous resolution is rare. After sterilization, remnant sperm remains in the ejaculatory ducts. The man is not considered sterile until he has produced sperm-free ejaculates as documented by semen analysis. This usually requires 15-20 ejaculations. Vasectomy prevents the passage of sperm into seminal fluid by blocking the vas deferens.
The failure rate is approximately 0.1%.
Vasectomy involves no hormones, is permanent, is an outpatient procedure, is quick, and carries minimal risk with regard to the procedure.
Patients may regret their decision after the procedure. Alternative contraception is required until the ejaculate is deemed free of sperm. Vasectomy does not prevent STDs. Short-term discomfort occurs.
Emergency Postcoital Contraception
Emergency postcoital contraception is defined as the use of a drug or device to prevent pregnancy after unprotected sexual intercourse. Unwanted pregnancy is common; worldwide, approximately 50 million pregnancies are terminated each year. In the United States each year, the widespread use of emergency contraception may have prevented more than 1 million abortions and 2 million pregnancies that end in childbirth.
A variety of different methods of emergency contraception have been described. Emergency contraceptives available in the United States include the emergency contraceptive pills (ECP), the Copper T380 IUD, the minipill emergency contraception method (MECM), and a progesterone agonist/antagonist. The Preven kit, the Plan B kit, and ulipristal (ella) are marketed as emergency contraceptives in the United States.
Candidates for emergency contraception include reproductive-aged women who have had unprotected sexual intercourse within 72 hours of presentation independent of the menstrual cycle. No known absolute contraindications to any of these methods have been described because exposure to the high dose of hormones is short lived. However, cases of deep vein thrombosis have been documented in women using the ECP method.
Emergency Contraceptive Pills and the Minipill Emergency Contraception Method
The ECP mode is marketed as Preven. It consists of 2 pills, which each contain 0.5 mg of levonorgestrel and 100 mcg of ethinyl estradiol, ingested 12 hours apart for a total of 4 pills. The first dose should be taken within the first 72 hours after unprotected intercourse; however, studies demonstrate effectiveness if the pills are taken after that period.
Only the progestin levonorgestrel has been studied for the use in MECM. It is marketed as Plan B. Its treatment schedule comprises 1 dose of 750 mcg levonorgestrel taken as soon as possible and no later than 48 hours after unprotected intercourse and a second dose taken 12 hours later.
A new formulation of Plan B is Plan B One-Step, an enteric-coated levonorgestrel emergency contraceptive pill (E-LNG-ECP) that both dissolves and is absorbed in the intestine. A Phase IV clinical trial found this OTC drug to be effective and safe for emergency contraception. In a study of 2445 Chinese women of reproductive age who took E-LNG-ECP, only 5 women became pregnant.
In June 2013, the FDA approved Plan-B One-Step as a nonprescription product for all women of childbearing potential. This action complies with allowing levonorgestrel-containing emergency contraceptives to be available as OTC products without age or point-of-sale restrictions.
Ulipristal is a selective progesterone receptor modulator with antagonistic and partial agonistic effects. When taken immediately before ovulation, ulipristal postpones follicular rupture. It is thought that the primary mechanism of action for emergency contraception is inhibition or delay of ovulation; however, alterations to the endometrium that may affect implantation may also occur. The treatment regimen is 30 mg (1 tablet) PO as soon as possible (within 120 hours [5 days]) after unprotected intercourse or a known/suspected contraceptive failure. If vomiting occurs within 3 hours after the dose, consider repeating the regimen.
The mechanism action of either the ECP or MECM is not clearly established. If administered before ovulation, both methods may inhibit follicular development and maturation, resulting in anovulation and deficient luteal function. Treatment following ovulation may affect the endometrium, thus inhibiting implantation. They also may affect tubal transport of the sperm or ova. However, menses and fertility return with the next cycle.
Most studies cite an effectiveness rate of 55-94%, with the true effectiveness rate likely to be approximately 75%. Based on one randomized trial comparing the ECP protocol with the MECM, the MECM seems to be just as effective with far less nausea and emesis. Patients must understand that the effective rate of 75% does not translate to a 25% failure rate. Instead, when considering 100 women who have had unprotected sexual intercourse during the middle 2 weeks of their cycle, approximately 8 will become pregnant. Of those 8 who have used ECPs, only 2 will then become pregnant. Despite this significant reduction in the rate of pregnancy, patients must understand that this method of contraception should be used only in emergencies and that they should be encouraged to use other more consistent forms of contraception.
Several factors complicate the calculation of a failure rate. Factors include dependence on the patient's history of their last menstrual period and day of exposure, effect of regular and irregular menstrual cycles on the calculation of the estimated time of ovulation, the possibility of the patient being pregnant, and the possibility that more than one unprotected coitus has occurred during that period.
Adverse effects include nausea and emesis, minor changes in menses, breast tenderness, fatigue, headache, abdominal pain, and dizziness. Ectopic pregnancy is possible if treatment fails.
Copper T380 Intrauterine Device
The Copper T380 IUD can be inserted as many as 7 days after unprotected sexual intercourse to prevent pregnancy. Insertion of the IUD is significantly more effective than either the ECP or MECP regimen, reducing the risk of pregnancy following unprotected intercourse by more than 99%.
Future Methods of Contraception
In 1996, the Institute of Medicine produced a report that examined the need for additional contraceptive choices and investigated the climate for development. The report was a follow-up to the 1990 Institute of Medicine evaluation of obstacles and opportunities for contraceptive development. Their findings noted that the array of contraceptive choices was limited in regard to specific health problems, cultural differences, life-cycle changes, and reproductive intentions. The committee also noted that regulatory issues, political pressures, and legal concerns have deterred pharmaceutical manufacturers from investigating new forms of contraception despite the evidence of need and market demand. As a result, the burden of research and development has shifted to small firms and nonprofit organizations that are not as well equipped to bring new contraceptives to market.
Although contraceptive development in the United States has slowed in the past few years, research outside of the United States continues at a rapid pace. In 2003, the Institute of Medicine published New Frontiers in Contraceptive Research: A Blueprint for Action, which identified priority areas for the development of new contraceptives. The report highlighted new technologies and approaches to biomedical research, including genomics and proteomics, that hold particular promise for developing new products and also identified impediments to drug development that must be addressed.
Reflecting this report, many new contraceptive designs are under investigation to provide more contraceptive options that have fewer adverse effects, are safer, and are more efficacious. As a final note to this article, a few of the newer methods and forms of contraception soon to be on the market are discussed below.
One of the more exciting new developments is a hormonal contraceptive method for men. The male birth control pill manipulates steroid hormones to decrease spermatogenesis and testosterone secretion.
Newer methods of subdermal implants are on the horizon. Uniplant is a single-rod implant system that consists of 55 mg of nomegestrol acetate in a capsule that is 3.5-cm long and 2.4 mm in diameter. Uniplant has been shown to be highly effective for as long as 1 year, with a frequency and degree of menstrual irregularities similar to those of Norplant.
Clinical studies are in progress for a biodegradable implant, Capnor, to eliminate the necessity of implant removal. This is a single 40-mm rod that contains levonorgestrel and maintains contraceptive protection for 1 year.
Biodegradable pellet implants containing norethindrone and cholesterol are currently undergoing investigation. They dissolve within 2 years and release the norethindrone for 12-18 months. Insertion of the pellets has been demonstrated to be simple; however, if the patient desires removal several months later, removal has been noted to be difficult.
The vaginal sponge, introduced in 1983 and taken off the market shortly thereafter, is making a comeback. The contraceptive was deemed safe by the FDA; however, the plant in which it was manufactured was not. American Home Product's plant had many problems, such as high levels of bacteria in its air and water, which were felt to be too costly to fix for a product that generated only $17 million yearly in sales. Allendale Pharmaceutical has now bought the patent and equipment and has moved production to a new plant. Allendale Pharmaceutical is currently in the process of sponge production and marketing; however, the company is still awaiting FDA inspection of the plant for adherence to health regulations before it can return the vaginal sponge to the market. This new version of the sponge has been available in Canada since 2003.
The vaginal sponge is made of soft disposable polyurethane foam that contains the spermicide nonoxynol-9. It offers an immediate and continuous presence of spermicide throughout a 24-hour period. The polyurethane foam is designed to trap and absorb semen before the entry of sperm into the cervix. Clinical trials have demonstrated an efficacy rate of 89% and 91% for parous and nulliparous women, respectively. However, in a Cochrane review of sponges versus the diaphragm, the sponge failure rate was 17.4% in a US trial and 24.5% in a British trial. The failure rates for a diaphragm were 12.8% and 10.9%, respectively. Unlike a diaphragm, the sponge does not have to be fitted and, in the 2 studies reviewed, it had overall equal efficacy in multiparous as nulliparous women.
The main advantage of the sponge over a diaphragm is its ready availability over the counter. The greatest risk with its use is the possibility of toxic shock syndrome (TSS). TSS is a rare, life-threatening bacterial infection that may occur if the sponge is left in place for more than 30 hours or if it is used while a woman is menstruating.
Lea's Shield is a one-size-fits-all diaphragmlike device soon to be available in the United States. This device consists of a 1-way valve that allows air to escape during placement, thus creating a suction effect against the cervix. The unilateral direction of the valve permits uterine and cervical fluids to be released into the vaginal canal but prevents sperm from entering. Currently, it is manufactured in Canada and Europe.
A few potential methods of tubal sterilization are under investigation. One of these new developments includes chemical scarring of the fallopian tubes. The scarring is a result of a combination of phenol and a thickening agent and phenol quinacrine that ultimately leads to blockage of the tubes. Another nonsurgical form of tubal sterilization is chemical plugs. Approved for use in Canada, this entails introduction of methyl cyanoacrylate (Krazy Glue) into the fallopian tubes. A reversible chemical plug can also be created by the injection of silicone into the fallopian tubes. The silicone eventually hardens but can be removed later. Chemical scarring and plugs are also under investigation as potential methods of vasectomy.
A pregnancy vaccine is one of the most controversial and exciting forms of contraception under development. Immunological factors can cause infertility, and fertile animals have been successfully immunized against pregnancy. Theoretically, it should be possible to develop vaccines capable of interfering with the reproductive process at different stages. The pregnancy vaccine, unlike anti-infective vaccines, stimulates an immune response against one or more host-specific antigens. The targets of the immune response are accessible to the immune system during a finite period, such as coitus (sperm antigens in the female), egg maturation (zona pellucida antigens), or successful fertilization (chorionic gonadotropin).
Currently, the major research focus is on the development of a vaccine that works by producing antibodies against human chorionic gonadotropin (hCG). In pregnant women, hCG is formed on about the 23rd day following midcycle conception. The hCG sends a signal to prevent menstruation. The presence of vaccine-induced anti-hCG antibodies can inhibit this signaling process and allow menstruation to proceed.
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