Early Pregnancy Loss in Emergency Medicine 

Updated: Nov 05, 2018
Author: Slava V Gaufberg, MD; Chief Editor: Jeter (Jay) Pritchard Taylor, III, MD 



Early pregnancy loss is estimated to occur in 10% of all clinically recognized pregnancies, with about 80% occurring in the first trimester.[1] The term "abortion" is commonly used to mean all forms of early pregnancy loss; however, due to the polarizing social stigma assigned to this term, the term "miscarriage" is used here to indicate all forms of spontaneous early pregnancy loss or potential loss. One of the common complications of pregnancy is spontaneous miscarriage, which occurs in an estimated 5-15% of pregnancies. Spontaneous miscarriages are categorized as threatened, inevitable, incomplete, complete, or missed, and can be further classified as sporadic or recurrent (>3 occurrences).


The pathophysiology of a spontaneous miscarriage may be suggested by its timing. Chromosomal defects are commonly seen in spontaneous miscarriages, especially those that occur during 4-8 weeks' gestation. Genetic etiologies are common in early first-trimester loss but may be seen throughout gestation. Trisomy chromosomes are the most common chromosomal anomaly. Insufficient or excessive hormonal levels usually result in spontaneous miscarriage before 10 weeks' gestation. Infectious, immunologic, and environmental factors are generally seen in first-trimester pregnancy loss. Anatomic factors are usually associated with second-trimester loss. Factor XIII deficiency and a complete or partial deficiency of fibrinogen are associated with recurrent spontaneous miscarriage.[2]

A prospective study by Jayasena et al indicated that in in asymptomatic pregnant women at 6 weeks’ gestation or more, low plasma levels of the hormone kisspeptin are associated with an increased miscarriage risk.[3]

A spontaneous miscarriage is a process that can be divided into 4 stages, as follows: threatened, inevitable, incomplete, and complete.

Threatened miscarriage

Vaginal bleeding, abdominal/pelvic pain of any degree, or both during early pregnancy represents a threatened miscarriage. Approximately a fourth of all pregnant women have some degree of vaginal bleeding during the first 2 trimesters. About half of these cases progress to an actual miscarriage.[4] Bleeding and pain accompanying threatened miscarriage is usually not very intense. Threatened miscarriage rarely presents with severe vaginal bleeding. On vaginal examination, the internal cervical os is closed and no cervical motion tenderness or tissue is found. Diffuse uterine tenderness, adnexal tenderness, or both may be present. Threatened miscarriage is defined by the absence of passing/passed tissue and the presence of a closed internal cervical os. These findings differentiate threatened miscarriage from later stages of a miscarriage.

Inevitable miscarriage

Vaginal bleeding is accompanied by dilatation of the cervical canal. Bleeding is usually more severe than with threatened miscarriage and is often associated with abdominal pain and cramping.

Incomplete miscarriage

Vaginal bleeding may be intense and accompanied by abdominal pain. The cervical os may be open with products of conception being passed, or the internal cervical os may be closed. Ultrasonography is used to reveal whether some products of conception are still present in the uterus.

Complete miscarriage

Patients may present with a history of bleeding, abdominal pain, and tissue passage. By the time the miscarriage is complete, bleeding and pain usually have subsided. Ultrasonography reveals a vacant uterus. Diagnosis may be confirmed by observation of the aborted fetus with the complete placenta, although caution is recommended in making this diagnosis without ultrasonography because it can be difficult to determine if the miscarriage is complete.


Causes of first- and second-trimester miscarriage

Embryonic abnormalities

Embryonic abnormalities account for 80-90% of first-trimester miscarriages. Note the following:

  • Chromosomal abnormalities are the most common cause of spontaneous miscarriage. More than 90% of cytogenic and morphologic errors are eliminated through spontaneous miscarriage.

  • Chromosomal abnormalities have been found in more than 75% of fetuses that miscarry in the first trimester.

  • The rate of chromosomal abnormalities increases with age, with a steep increase in women older than 35 years.

  • Trisomy chromosomes commonly are encountered, with trisomy 16 accounting for approximately a third of chromosomal abnormalities in early pregnancy.

Maternal factors

Maternal factors account for the majority of second-trimester miscarriages, with advanced age and a previous early pregnancy loss as the most common risk factors.[1] Chronic maternal health factors include the following:

  • Maternal insulin-dependent diabetes mellitus (IDDM): As many as 30% of pregnancies in women with IDDM result in spontaneous miscarriage, predominantly in patients with poor glucose control in the first trimester.

  • Severe hypertension

  • Renal disease

  • Systemic lupus erythematosus (SLE)

  • Hypothyroidism and hyperthyroidism

Acute maternal health factors include the following:

  • Infections (eg, rubella, cytomegalovirus [CMV], and mycoplasmal, ureaplasmal, listerial, toxoplasmal infections)

  • Trauma

Severe emotional shock may also cause first- and second-trimester miscarriages.

Other factors that may contribute to miscarriage

Exogenous factors include the following:

  • Alcohol

  • Tobacco

  • Cocaine and other illicit drugs

Anatomic factors include the following:

Congenital or acquired anatomic factors are reported to occur in 10-15% of women who have recurrent spontaneous miscarriages.

  • Congenital anatomic lesions include müllerian duct anomalies (eg, septate uterus, diethylstilbestrol [DES]-related anomalies). Müllerian duct lesions usually are found in second-trimester pregnancy loss.

  • Anomalies of the uterine artery with compromised endometrial blood flow are congenital.

  • Acquired lesions include intrauterine adhesions (ie, synechiae), leiomyoma, and endometriosis.

  • Other diseases or abnormalities of the reproductive system that may result in miscarriage include congenital or acquired uterine defects, fibroids, cervical incompetence, abnormal placental development, or grand multiparity.

Endocrine factors include the following:

  • Endocrine factors potentially contribute to recurrent miscarriage in 10-20% of cases.

  • Luteal phase insufficiency (ie, abnormal corpus luteum function with insufficient progesterone production) is implicated as the most common endocrine abnormality contributing to spontaneous miscarriage.

  • Hypothyroidism, hypoprolactinemia, poor diabetic control, and polycystic ovarian syndrome are contributive factors in pregnancy loss.

Infectious factors include the following:

  • Presumed infectious etiology may be found in 5% of cases.

  • Bacterial, viral, parasitic, fungal, and zoonotic infections are associated with recurrent spontaneous miscarriage.

Immunologic factors include the following:

  • Immunologic factors may contribute in up to 60% of recurrent spontaneous miscarriages.

  • Both the developing embryo and the trophoblast may be considered immunologically foreign to the maternal immune system.

  • Antiphospholipid antibody syndrome generally is responsible for more second-trimester pregnancy losses than first-trimester losses.

Miscellaneous factors

Miscellaneous factors may account for up to 3% of recurrent spontaneous miscarriages. Other contributing factors implicated in sporadic and recurrent spontaneous abortions include environment, drugs, placental abnormalities, medical illnesses, and male-related causes.

Gestational exposure to nonaspirin NSAIDs may increase the risk for miscarriage. Nakhai-Pour et al identified 4705 women who had spontaneous abortions by 20 weeks' gestation. Each case was matched to 10 control subjects (n=47,050) who did not have a spontaneous abortion. In the women who had a miscarriage, 352 (7.5%) were exposed to a nonaspirin NSAID, whereas NSAID exposure was lower (1213 exposed [2.6%]) in women who did not have a miscarriage.[5]

On the other hand, a study by Daniel et al suggested that for the most part, gestational exposure to nonaspirin NSAIDs does not increase the risk for spontaneous miscarriage. In a study cohort that included 65,457 women who conceived during the study period, a total of 6508 (9.9%) experienced spontaneous miscarriage. Exposure to NSAIDs was not found to be an independent risk factor for miscarriage, with the exception of indomethacin, which, the study indicated, is significantly associated with spontaneous abortion following first-trimester exposure.[6]


United States statistics

Many pregnancies are not viable. According to estimates, 50% of pregnancies terminate spontaneously before the first missed menstrual period; these miscarriages usually are not clinically recognized. Spontaneous miscarriage is typically defined as a clinically recognized (ie, by blood test, urine test, or ultrasonography) pregnancy loss before 20 weeks' gestation. Approximately 5-15% of diagnosed pregnancies result in spontaneous miscarriage.


Some European investigators quote the rate of spontaneous miscarriage to be as low as 2-5%. Chinese researchers concluded that increased parental exposure to phenols is associated with spontaneous abortion.[7]

Race- and age-related demographics

Surveillance data for pregnancy-related deaths demonstrate more deaths due to ectopic pregnancy, spontaneous miscarriage, and induced abortion among African American women than among white women. Eight percent of pregnancy-related deaths among black women were due to ectopic pregnancies; 7% were due to miscarriages. Among white women, data show that 4% of pregnancy-related deaths were due to ectopic pregnancies; 4% were due to miscarriages.[8, 9]

Age and increased parity affect a woman's risk of miscarriage. In women younger than 20 years, miscarriage occurs in an estimated 12% of pregnancies. In women older than 20 years, miscarriage occurs in an estimated 26% of pregnancies.

Age primarily affects the oocyte. When oocytes from young women are used to create embryos for transfer to older recipients, implantation and pregnancy rates mimic those seen in younger women. The number of miscarriages and chromosomal anomalies decreases, suggesting that the uterus is not responsible for poor outcomes in women of advanced reproductive age.


The prognosis for a successful pregnancy depends upon the etiology of previous spontaneous miscarriages, the age of the patient, and the sonographic appearance of the gestation.

Correction of an endocrine abnormality in women with recurrent miscarriage has the best prognosis for a successful pregnancy (>90%).

In women with an unknown etiology of prior pregnancy loss, the probability of achieving successful pregnancies is 40-80%.

The live-birth rate after documentation of fetal cardiac activity at 5-6 weeks of gestation in women with 2 or more unexplained spontaneous miscarriages is approximately 77%.

When the transvaginal pelvic sonogram shows an embryo of at least 8 weeks estimated gestational age (EGA) and cardiac activity, the miscarriage rate for patients younger than 35 years is 3-5% and for those older than 35 years is 8%.

Unfavorable sonographic prognostic indicators are a fetal cardiac activity rate that is slower than 90 beats per minute, an abnormally shaped or sized gestational sac, and a large subchorionic hemorrhage.

The overall miscarriage rate for patients older than 35 years is 14% and for patients younger than 35 years is 7%.


Surveillance data suggest that spontaneous miscarriages and induced abortions accounted for about 4% of pregnancy-related deaths in the United States.[8]


Potential complications of early pregnancy loss include septic miscarriage and hypovolemic or septic shock.

Preexisting anemia may make patients more susceptible to hypovolemic shock.

Patients with HIV infection who are undergoing curettage may have a higher rate of procedure-related complications but no increase in infectious morbidity.

Coagulation defects may be associated with a retained dead fetus.

Other possible complications include post miscarriage bleeding, retained products of conception, and hematometra.

A prospective survey study by Farren et al found that 28% of women surveyed after early pregnancy loss met the criteria for probably post-traumatic stress disorder at one month and 38% at three months.[10, 11]

Patient Education

Advise patients to return to the ED upon occurrence of symptoms such as the following:

  • Profuse vaginal bleeding (more than 1 pad/hour)

  • Severe pelvic pain

  • Temperature above 38°C (100.4°F)

Patients may experience intermittent menstrual-like flow and cramps during the following week. The next menstrual period usually occurs in 4-5 weeks.

Patients can resume regular activities when able to but should refrain from intercourse and douching for approximately 2 weeks.

For patient education resources, see Pregnancy Center, as well as Bleeding During Pregnancy, Miscarriage, Abortion, and Dilation and Curettage (D&C).




Patients with spontaneous miscarriage usually present to the ED with vaginal bleeding, abdominal pain, or both. Note the following:

  • Vaginal bleeding may vary from slight spotting to a severe life-threatening hemorrhage. The patient's history should include the number of pads or tampons used. Hasan et al found that heavy bleeding in the first trimester, particularly when associated with abdominal pain, is associated with higher risk of miscarriage.[12]

  • Presence of blood clots or tissue may be an important sign indicating progression of spontaneous miscarriage.

  • Abdominal pain is usually located in the suprapubic area or in one or both lower quadrants.

  • Pain may radiate to the lower back, buttocks, genitalia, and perineum.

The patient's history should also include the following:

  • Date of last menstrual period (LMP)

  • Estimated length of gestation

  • Sonogram results, if previously performed

  • Bleeding disorders

  • Previous miscarriage or elective abortions

Other symptoms, such as fever or chills, are more characteristic of a septic miscarriage or abortion.

Consider any woman of childbearing age with vaginal bleeding pregnant until proven otherwise.


Pelvic examination should focus on determining the source of bleeding, such as the following:

  • Blood from cervical os

  • Intensity of bleeding

  • Presence of clots or tissue fragments

  • Cervical motion tenderness (presence increases suspicion for ectopic pregnancy)

  • Status of internal cervical os: open indicates inevitable or possibly incomplete miscarriage; closed indicates threatened miscarriage.

  • Uterine size and tenderness, as well as adnexal tenderness or masses

Signs of threatened miscarriage include the following:

  • Vital signs should be within reference ranges unless infection is present or hemorrhage has caused hypovolemia.

  • The abdomen usually is soft and nontender.

  • Pelvic examination reveals a closed internal cervical os. The bimanual examination is unremarkable.

Signs of incomplete miscarriage include the following:

  • The cervix may appear dilated and effaced, or it may be closed.

  • Bimanual examination may reveal an enlarged and soft uterus.

  • On pelvic examination, products of conception may be partially present in the uterus, may protrude from the external os, or may be present in the vagina. Bleeding and cramping usually persist.

Signs of complete miscarriage: On pelvic examination, the cervix should be closed, and the uterus should be contracted.

Signs of missed miscarriage include the following:

  • Vital signs usually are within reference ranges. Abdominal examination may or may not reveal a palpable uterus. If palpable, the uterus usually is small for the presumed gestational age.

  • Fetal heart tones are inaudible or unseen on sonogram.

  • The cervical os is closed upon pelvic examination. The uterus may feel soft and enlarged.



Diagnostic Considerations

Important considerations

Perform pregnancy testing for every woman of childbearing age who presents with lower abdominal pain, vaginal bleeding, or both. History alone is not sufficient to exclude pregnancy. Pregnancy is possible even if the patient gives a history of a recent normal menstrual period, lactation, or contraceptive use.

Rule out ectopic pregnancy. An ectopic pregnancy must be excluded in every pregnant woman with abdominal pain, vaginal bleeding, or both during the first or second trimester. Endometrial shedding, which clinically simulates miscarriage, may occur with an ectopic pregnancy. This misdiagnosis is the greatest potential pitfall. An empty uterus on sonogram may represent an ectopic pregnancy.

Prevent hemolytic disease of the newborn. Ascertain the blood type of every pregnant patient with vaginal bleeding. If the patient is Rh-negative, administer RhoGAM to prevent hemolytic disease of the newborn (see Medication).

Assess the intensity of hemorrhage. External bleeding may not accurately reflect total hemorrhage. The patient, especially in the supine position, may collect large amounts of blood in the vagina with minimal external bleeding. Similarly, a large quantity of retained blood may be present in the uterine cavity and, in the case of ectopic pregnancy, in the peritoneal cavity. Therefore, never rely on the external examination to assess the rate of hemorrhage in patients with vaginal bleeding. Always perform a pelvic examination to look for blood collection in the vagina, disproportionately tender uterus, and signs of peritoneal irritation.

Identify retained products of conception. Ultrasonography for the diagnosis of retained products can yield false-positive rates, with one report of an overall false-positive rate of 34%. Retained products may be more commonly found when an evacuation is performed after 15 weeks' gestation.

Special considerations

Offer grief counseling to all patients after a miscarriage.

Referral to a specialist for determination of the cause of recurrent miscarriage may be indicated.[13]

Differential Diagnoses



Laboratory Studies

Laboratory studies may include the following:

  • Qualitative urine pregnancy test, to confirm pregnancy

  • Complete blood count with differential

  • Blood type and Rh factor: Blood type must be documented for every pregnant patient with vaginal bleeding. If Rh-negative, administer RhoGAM to prevent hemolytic disease of the newborn in this pregnancy and subsequent pregnancies.

  • Hemoglobin and hematocrit: These studies establish baseline and detect hemorrhagic anemia.

  • Factor XIII and fibrinogen, if indicated per history

Quantitative human chorionic gonadotropin-beta

The discriminatory level of beta-hCG is approximately 1500 mIU/mL above which there should be sonographic evidence of early intrauterine pregnancy, if present. Beta-hCG level rises at rate of doubling approximately every 48 hours for 85% of intrauterine pregnancies. The remaining 15% may rise with a different slope or be plateaued.

A higher likelihood of ectopic pregnancy or subsequent miscarriage exists if hCG blood level is lower than predicted by estimated gestational age (GA) based on the last menstrual period (LMP).

The possibility of molar pregnancy exists if beta-hCG is very high and out of proportion to predicted gestational age. This pregnancy occurs with or without evidence of early normal trophoblast growth and function, as indicated by adequately rising beta-hCG levels.

Imaging Studies

Ultrasonography is used widely and is the imaging study of choice. Advantages of ultrasonography include bedside use, availability, low cost, and noninvasiveness. Disadvantages include operator dependency.

Ultrasonography aids identification of retained products of conception, fetal demise, incomplete miscarriage, ectopic pregnancy, or empty uterus; therefore, it provides a clinically relevant classification of early pregnancy loss. Following spontaneous first-trimester complete miscarriage, endovaginal ultrasonography has been found to be 81% sensitive and 94% specific in detection of retained products of conception.[14] Ultrasonography is the most accurate diagnostic modality in the confirmation of a viable pregnancy during the first trimester.[14]

Transabdominal ultrasonography of the pelvis provides an overall view of the pelvic structures. A full bladder is required as a sonographic window.

Endovaginal ultrasonography gives a detailed view of the endometrium of the uterus, ovaries, adnexa, and cul-de-sac. An empty bladder is required for optimal imaging.

Indications for ultrasonography in the ED include abdominal or pelvic pain, vaginal bleeding, persistently open cervical os, adnexal mass or fullness, cervical motion tenderness, discrepancy between uterine size and last menstrual period (LMP), and discrepancy between expected and measured beta-hCG levels.

Seymour et al sought to determine whether a physical examination was necessary in pregnant patients presenting with pregnancy-related complaints and a viable pregnancy as shown on bedside ultrasonography. Fifty patients were enrolled in the study; each patient received a pelvic examination before ultrasonography. In all patients, findings on physical examination were the same as those found by ultrasonography. Bedside ultrasonography provided all the information needed to determine immediate management of these patients. Few findings on pelvic examination are likely to alter this management.[15]

The findings of the study by Seymour et al also complement the findings of Close et al, who found there was very little inter-examiner reliability of the bimanual pelvic examination for identifying masses or uterine size,[16] which are principally the physical findings being evaluated in the early pregnant patient in the ED setting. Taken together, these studies highlight the impact that advances in technology has on the practice of medicine, but, at this time, the findings are unlikely to change current practice.

A high-resolution vaginal ultrasound probe can detect pregnancy at 3-4 weeks' gestation and fetal heart activity at 5 and a half weeks. The presence of fetal cardiac activity in women with bleeding in early pregnancy has been noted to have a sensitivity of 97% and a specificity of 98% for fetal survival to the 20th week of pregnancy.[14]

Fetal studies are limited in the first trimester due to small fetal size. Ultrasonography usually provides information in 3 major areas: location of pregnancy, pregnancy size, and absence or presence of fetal cardiac activity.

An apparently empty uterus revealed by ultrasonography in a pregnant woman (ie, positive beta-hCG findings, LMP within last 20 wk) suggests a very early pregnancy (ie, < 3 wk GA), a completed miscarriage, or an ectopic pregnancy. (See Bedside Ultrasonography, First-Trimester Pregnancy.)

Sonographic signs suggestive of a nonviable pregnancy include the following:

  • Irregular gestational sac (ie, gestational sac >25-mm mean sac diameter [MSD] on transabdominal sonogram; >16-mm MSD on endovaginal sonogram without a detectable embryo)

  • Nonliving embryo (embryo without a heartbeat)

  • Presence of abnormal hyperechoic material within the uterine cavity, as depicted in the sonogram below

    This endovaginal longitudinal view demonstrates fl This endovaginal longitudinal view demonstrates fluid within the uterus (Ut). Echogenic debris also is present within the endometrial cavity. This image shows a large pseudogestational sac of an ectopic pregnancy.

The Society of Radiologists in Ultrasound indicate the following findings are diagnostic of early pregnancy loss[1] :

  • A fetal crown–rump length of 7 mm or greater and absent heartbeat
  • A mean sac diameter of 25 mm or greater without an embryo
  • Absence of an embryo with a heartbeat 2 weeks or longer after a scan that showed a gestational sac without a yolk sac
  • Absence of an embryo with a heartbeat 11 days or longer after a scan that showed a gestational sac with a yolk sac

Consider the sonographic diagnosis of early pregnancy failure in relationship to developmental stage. Note the following:

  • Subclinical or preclinical loss: This occurs within the first 2 weeks after conception. Sonographic evidence of pregnancy does not exist at this stage.

  • Loss at 5-6 weeks: Loss at this stage is based upon gestational sac characteristics. Abnormal gestational sac size is the most reliable indicator of abnormal outcome. Gestational sacs should be 5-mm mean sac diameter (MSD) by the fifth gestational week. An abnormally large gestational sac, as determined by high-frequency endovaginal sonography (HFEVS), is observed when the MSD is more than 8 mm without a demonstrable yolk sac or is more than 16 mm without a demonstrable embryo.

  • Loss at 7-8 weeks: Sonographic evidence is based upon demonstration of an abnormal embryo or gestational sac.

  • Loss at 9-12 weeks: Sonographic diagnosis of embryonic demise is usually made on demonstration of an abnormal fetus. Sonographic evidence of a fetus lacking cardiac activity is the most specific indicator of embryonic demise. This is depicted in the sonogram below.

    This endovaginal ultrasonogram reveals an irregula This endovaginal ultrasonogram reveals an irregular gestational sac with an amorphic fetal pole. No fetal cardiac activity was noted. This image represents a missed miscarriage or fetal demise.

Caution is advised in the diagnosis of embryonic demise. Determination of whether the viewed structure is the embryo is critical, as no other morphologically recognizable structures, other than a heartbeat, exist at this stage of development. The embryo must be scanned thoroughly for evidence of a heartbeat. Note the following:

  • Most recommendations call for 2 independent examiners to view the embryo, either concurrent with the ED visit or at follow-up.

  • Most sonographers recommend repeating the scan within 3-7 days to determine if normal development is occurring.

  • On follow-up, a falling beta-human chorionic gonadotropin (hCG) level, as well as abnormal fetal development, confirms embryonic demise.

Sonography can identify presence of a subchorionic hematoma or hemorrhage (ie, bleeding between the endometrium and the gestational sac) and may include the following features:

  • A subchorionic hemorrhage is the most commonly identified source of first-trimester bleeding, appearing on sonography as a crescent-shaped hypoechoic area next to the gestational sac.

  • Subchorionic hemorrhage encompasses a spectrum of sonographic findings. Subchorionic fluid can be classified in relation to gestational sac size and length of gestation. Subchorionic bleeding is present when pulsation of the subchorionic fluid is noted.

  • Size of the subchorionic hemorrhage should be taken into consideration, as greater size relates to an increased risk of spontaneous miscarriage. A large subchorionic hematoma (ie, surrounding greater than 50% of the gestational sac) is a poor prognostic indicator for the pregnancy outcome. A subchorionic hemorrhage is depicted below.

    This endovaginal ultrasonographic image demonstrat This endovaginal ultrasonographic image demonstrates a subchorionic hemorrhage (SH) less than half the gestational sac size.
  • Subchorionic bleeding can be demonstrated using color Doppler imaging.

  • Endovaginal ultrasonography should be applied whenever possible to limit image distortion due to patient habitus or an overdistended bladder.

An incomplete miscarriage may demonstrate a variety of sonographic findings as follows:

  • The gestational sac may be misshaped or collapsed, or it may be intact, containing a nonliving embryo. In addition, an irregular complex mass within the endometrial or endocervical canal may be present. Sonogram of an incomplete miscarriage is shown below.

    This image shows an endovaginal longitudinal view This image shows an endovaginal longitudinal view of a low-lying gestational sac (GS) within the uterus (Ut), representing an incomplete miscarriage.
  • Echogenic material or debris within the endometrial canal may represent retained products of conception or clotted blood.

  • First-trimester molar pregnancies may simulate an incomplete miscarriage, with echogenic material within the endometrial cavity that has no characteristic vesicles or cysts.

  • Intrauterine fluid collections may represent pseudogestational sacs found in ectopic pregnancies.

  • Studies suggest no statistically significant relationship between the initial presence of a gestational sac or endometrial thickness and the success rate of expectant management.

A complete miscarriage may demonstrate the following sonographic findings:

  • An empty uterus noted on endovaginal sonogram suggests a complete miscarriage; however, sonographic diagnosis includes ectopic pregnancy and early intrauterine pregnancy.

  • Careful scanning for adnexal masses and/or free fluid is advised.

No single ultrasonographic measurement of the different anatomical features in the first trimester has demonstrated a high predictive value for determining early pregnancy outcome. Relatively recent research suggests the finding of blood flow in the intervillous space in cases of first-trimester miscarriage using color Doppler ultrasonography as useful in the prediction of successful expectant management. Miscarriages with intervillous space blood flow were 4 times more likely to complete with expectant management.



Prehospital Care

Maintain routine universal precautions in view of potentially heavy vaginal bleeding. Emergency medical services (EMS) personnel should be aware of the potential for hemorrhagic shock and should treat any hemodynamic instability.

Obtain vital signs and establish an intravenous line in all pregnant patients who have abdominal pain and vaginal bleeding. If the patient is hypotensive, an intravenous bolus of normal saline (NS) is indicated for hemodynamic stabilization.

Administer oxygen.

Encourage the patient to bring any passed tissue to the hospital for evaluation.

Emergency Department Care


Treat all patients with vaginal bleeding of any etiology as follows:

  • Determine hemodynamic stability and treat instability. If the patient is in hemorrhagic shock, treatment includes the Trendelenburg position, oxygen, aggressive fluid resuscitation (at least 2 large-bore IV lines with lactated Ringer [LR] solution or normal saline, wide open), and hemotransfusion.

  • Determine pregnancy status (qualitative and quantitative).

  • Make laboratory determination of hematocrit (Hct) level and Rh status.

  • Perform a pelvic examination to determine the rate of bleeding; presence of blood clots or products of conception; and condition of cervical os, cervix, uterus, and adnexa.

  • Perform pelvic ultrasonography to determine intrauterine and/or extrauterine contents (fetal heart activity) and/or to clinically classify spontaneous miscarriage.

The American College of Obstetricians and Gynecologists (ACOG) recommends generally limiting expectant management to gestations within the first trimester owing to potential hemorrhage as well as a lack of safety studies of expectant management in the second trimester.[1] An estimated 80% success rate in achieving complete expulsion when adequate time is allowed (≤8 weeks). For women who wish to reduce the time to complete expulsion but do not wish to undergo surgical evacuation, treatment with misoprostol may be considered.[1]

Nadarajah et al found no statistically significant difference in the success rate between 360 women who underwent expectant or surgical management of early pregnancy loss, nor was there any difference in the types of miscarriage.[17] With expectant management, 74% patients had a complete spontaneous expulsion of products of conception. Of these patients, 106 (83%) miscarried within 7 days. However, the rates of unplanned admissions (18.1%) and unplanned surgical evacuations (17.5%) in the expectant group, were significantly higher than those in the surgical group (7.4% and 8% respectively).[17]

Diagnostic specific management

Inevitable miscarriage

The goal of treatment is evacuation of the uterus to prevent complications (eg, further hemorrhage, infection).

Incomplete miscarriage

If tissue, blood clots, or products of conception are found in the cervical os, remove them with ring forceps to facilitate uterine contractions and hemostasis. For the same reason, use oxytocin in cases of severe bleeding (10-20 mcg/L of NS, wide open).

Administer RhoGAM to a gravid patient who is Rh-negative and is experiencing vaginal bleeding.

Consider hemotransfusion in the case of severe bleeding, hemodynamic instability, or both.

Consider treatment with misoprostol to facilitate completion of the miscarriage.

Complete miscarriage

Treatment of a patient who has had a complete miscarriage varies depending on the degree of certainty of the diagnosis. Diagnosing complete miscarriage in the ED can be difficult, unless an intact gestational sac was expelled.

If pelvic examination produces fetal tissue (or material of similar appearance), send it to the laboratory for identification of possible products of conception.

Missed miscarriage

Treatment may vary depending on gestational age as follows:

  • First trimester: Most patients pass the products of conception spontaneously. Coagulation defects secondary to a dead fetus are rare. Expectant management,[18] suction curettage, or misoprostol for medical management to facilitate passage of products of conception may be performed.[19]

  • Second trimester: The uterus is emptied by dilatation and evacuation; alternatively, the uterus is emptied by induction of labor.


If vaginal bleeding cannot be controlled in the ED, transfer the patient to the operating room (OR) for examination. Anesthetize the patient and perform uterine evacuation.


Transfer patients with evidence of a coagulation disorder to a higher level of care.


Consultation with an obstetrician/gynecologist is indicated in all patients with the diagnosis of inevitable or incomplete miscarriage; patients with severe hemorrhage or patients who are hemodynamically unstable require immediate consultation for assistance with definitive treatment. Definitive treatment may be to evacuate the products of conception from the uterus with curettage. Depending on hospital policy, curettage may be performed in the emergency department with subsequent observation of patients for 4-6 hours after curettage, and then discharge if no complications occur. Curettage is generally reserved for those patients who are at risk for hemodynamic instability due to the briskness of bleeding or for those in whom endometritis is a concern. However, most patients with inevitable or incomplete miscarriage are candidates for medical management with misoprostol.[20, 21, 22, 23]



A study by Coomarasamy et al randomly assigned 836 women with recurrent miscarriages to receive treatment with progesterone or a placebo to investigate whether the live birth rate would increase in the group that was treated with progesterone. The study did not find a significant increase as the rate of live births was 65.8% (262 of 398 women) in the progesterone group and 63.3% (271 of 428 women) in the placebo group.[24, 25]

Long-Term Monitoring

Threatened miscarriage

Counsel all patients discharged from the ED (with any stage of miscarriage) regarding possible complications. OB/GYN follow up in 1-2 days should be arranged.

Incomplete miscarriage

After the first dose of misoprostol is administered intravaginally, the patient may be discharged to follow up with her OB/GYN in 24-48 hours.

If a curettage is performed in the ED, the patient should be observed for 4-6 hours. If stable, the patient can be discharged.

Administer the standard dose of Rho(D) immune globulin (ie, 300 mcg) to women who are Rh-negative to prevent Rh immunization (see Medication).

Send the products of conception for pathologic evaluation.

Missed miscarriage

Ultrasonographic findings, in association with presence or absence of significant clinical bleeding, may aid in determination of medical versus expectant management as well as urgent versus routine follow-up.

In the case of expectant management, advise the patient to return to the ED or to contact an OB/GYN if severe cramping, bleeding, fever, and/or passage of tissue occur.

In the case of medical management with misoprostol, the first dose of 800 micrograms may be administered intravaginally in the ED, with follow up to an OB/GYN in 24-48 hours. Patients should be warned to return to the ED or contact their OB/GYN immediately for severe cramping, bleeding, fever, and/or passage of tissue.



Medication Summary

The goals of pharmacotherapy are to prevent complications and to reduce morbidity.

Immune globulins

Class Summary

This agent suppresses immune response and antibody formation.

Rho(D) Immune Globulin (RhoGAM)

In nonsensitized Rho(D)-negative mothers who are exposed to Rho(D) prevents antibody formation to Rh-positive red blood cells of the fetus caused by abortion, fetomaternal hemorrhage, abdominal trauma, amniocentesis, full-term delivery, or transfusion accident.

Oxytocic Agent

Class Summary

This agent has vasopressive effects and prevents postpartum bleeding.

Oxytocin (Pitocin, Syntocinon)

Produces rhythmic uterine contractions and can control postpartum bleeding or hemorrhage.


Class Summary

These agents induce uterine contractions.

Misoprostol (Cytotec)

Not approved for use in pregnancy, yet is an invaluable medication widely used for cervical preparation for miscarriage, labor induction, and as a medical abortifacient. Provides safe, passive method of cervical dilatation and should be considered for facilitation of passage of products of conception in the setting of inevitable or incomplete miscarriage, preabortion ripening when prior uterine surgery (ie, LEEP, cesarean delivery) are known risk factors for uterine perforation during surgical abortion. Can be administered orally or vaginally. Some studies show premoistened tablets placed vaginally help absorption. Patients can be instructed in self-administration to help time the dose in synchrony with their abortion procedure.

In a study by Singh of primigravid women (6-11 wk gestation), 93.3% achieved dilatation of the cervix of 8 mm or greater after 3 h postintravaginal misoprostol 400 mcg, whereas only 16.7% of women achieved this after 2 h of 600 mcg. The 600-mcg group had slightly greater adverse effects (eg, bleeding, abdominal pain, fever >38ºC).

Dosage intended for cervical ripening can induce abortion in some patients. Oral doses of 100-400 mcg can be combined with vaginal insertion of prostaglandins to enhance cervical dilatation.


Questions & Answers


How is early pregnancy loss classified?

What is the pathophysiology of early pregnancy loss?

What is the pathophysiology of threatened miscarriage?

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Which lab tests are performed in the workup of early pregnancy loss?

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Which medications in the drug class Prostaglandin are used in the treatment of Early Pregnancy Loss in Emergency Medicine?

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Which medications in the drug class Immune globulins are used in the treatment of Early Pregnancy Loss in Emergency Medicine?