eMedicine Specialties > Radiology > Obstetrics/Gynecology

Ectopic Pregnancy

Author: Douglas Bourgon, MD, Diagnostic Radiologist, Image Guided Therapeutics
Coauthor(s): Eric Outwater, MD, Professor, Department of Radiology, University of Arizona; Gregory J Balmforth, MD, Staff Physician, Department of Diagnostic Radiology, University of Arizona Medical Center
Contributor Information and Disclosures

Updated: Jul 18, 2008

Introduction

Ectopic pregnancy continues to be the leading cause of first-trimester maternal death. Although diagnosis and management have improved, the incidence of this disease has continued to climb since the US Centers for Disease Control and Prevention (CDC) started collecting data in 1970.1,2 This increase is likely due to a continued rise in the prevalence of predisposing risk factors. Ectopic pregnancy has additional significance in that the associated mortality with this condition usually affects an otherwise healthy segment of the population.

Axial T2-weighted fast spin-echo magnetic resonan...

Axial T2-weighted fast spin-echo magnetic resonance image of the pelvis (same patient as in Images 11-14). This image shows an abnormal fluid-containing fallopian tube (red arrow) on the right side. A simple right ovarian cyst (white arrow) is also present.

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Axial T2-weighted fast spin-echo magnetic resonan...

Axial T2-weighted fast spin-echo magnetic resonance image of the pelvis (same patient as in Images 11-14). This image shows an abnormal fluid-containing fallopian tube (red arrow) on the right side. A simple right ovarian cyst (white arrow) is also present.


Coronal T2-weighted fat-saturated magnetic resona...

Coronal T2-weighted fat-saturated magnetic resonance image of the pelvis (same patient as in Images 11-14). This image shows an abnormal fluid-containing fallopian tube (red arrow) on the right side. A simple ovarian cyst (white arrow) is also present on the right.

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Coronal T2-weighted fat-saturated magnetic resona...

Coronal T2-weighted fat-saturated magnetic resonance image of the pelvis (same patient as in Images 11-14). This image shows an abnormal fluid-containing fallopian tube (red arrow) on the right side. A simple ovarian cyst (white arrow) is also present on the right.


For excellent patient education resources, visit eMedicine's Pregnancy and Reproduction Center, Women's Health Center, and Sexually Transmitted Diseases Center. Also, see eMedicine's patient education article Ectopic Pregnancy.


Related eMedicine topics:

 Pelvic Inflammatory Disease/Tubo-ovarian Abscess

Pregnancy, Ectopic

Surgical Management of Ectopic Pregnancy

Pathophysiology

The physiologic and physical needs for normal growth and development of a fetus, including the decidual reaction, as well as hematologic and spatial requirements, are not provided outside of the uterus. The initial stages of gestation outside the uterus (ectopic pregnancies), however, do occur. Locations of such ectopic pregnancies include interstitial (cornual), cervical, and intra-abdominal sites. Most ectopic pregnancies, however, occur in the isthmic or ampullary portions of the fallopian tube.3

Compromise to the physiologic and physical needs for fetal growth when in an ectopic location usually results in fetal demise, either through rupture or involution of the gestational sac. Rupture of the ectopic pregnancy can place the mother at significant risk.

Laboratory detection of beta–human chorionic gonadotropin (beta-HCG) is required for the diagnosis of an ectopic pregnancy. Although beta-HCG levels and their rate of increase may vary with ectopic pregnancies, a negative beta-HCG result effectively excludes the diagnosis of an intrauterine or extrauterine pregnancy. A chronic ectopic pregnancy, however, can have low beta-HCG levels.

Although a positive beta-HCG result is highly specific for gestation, the analysis of beta-HCG levels is affected by the fact that at least 2 laboratory reporting standards are still used in practice. These include the International Reference Preparation (IRP), which is considered more pure than the previous Second International Standard (2IS). IRP values are approximately twice the value of the 2IS values.4,5 Knowledge of the laboratory standard used at individual institutions is needed, particularly in evaluating the discriminatory levels of beta-HCG that are considered necessary to be reached before one can expect to image various structures (eg, gestational sac).

Frequency

United States

The CDC estimated that approximately 108,800 ectopic pregnancies occurred in 1992.1 This number represented approximately 2% of all pregnancies. However, these estimates are considered conservative, because patients whose condition was diagnosed and managed exclusively through private offices would not have been included in that data set.

With documented intrauterine pregnancy, the risk of concomitant ectopic (heterotopic) pregnancy is approximately 1 case in 7000 patients.2 This risk has been reported to increase to approximately 1 case in 100 patients if the woman is being treated for infertility,4 although this elevated risk may largely be related to the underlying need for assisted reproductive treatment (ART) rather than a direct association with the therapy.6

Mortality/Morbidity

  • Ectopic pregnancy accounts for 9% of all pregnancy-related deaths.1
  • Morbidity includes a significantly increased risk for future ectopic pregnancy, possible infertility due to scarring or surgical resection of the fallopian tube, and potential adverse effects or complications related to drug therapy.7,8

Race

No race predilection for ectopic pregnancy is reported.

Sex

Women of childbearing age are affected.

Age

Women of childbearing age are affected.

Anatomy

Approximately 95% of ectopic pregnancies occur in the ampullary or isthmic portions of the fallopian tubes.2  About 2-5% occur as interstitial (cornual) ectopic pregnancies. The rare remaining locations include cervical, fimbrial, ovarian, and peritoneal sites, as well as previous cesarean section scars.2,9

Presentation

The classic clinical triad of an ectopic pregnancy includes pain, vaginal bleeding, and an adnexal mass.

The clinical triad, however, is nonspecific and present in less than 50% of ectopic pregnancies. The positive predictive value of the triad is only 14%.2,4,7

Risk factors for ectopic pregnancy include the following5,7 :

Preferred Examination

To diagnose an ectopic pregnancy, beta-HCG tests are required. A negative beta-HCG result effectively excludes the diagnosis of an ectopic or intrauterine pregnancy.

In unstable patients, surgical evaluation and/or laparoscopy should be performed with or without culdocentesis. In patients with a stable clinical condition, transabdominal (TA) and endovaginal (EV) ultrasonography are performed. The demonstration of an intrauterine gestational sac effectively excludes the diagnosis of an ectopic pregnancy. A search for a possible ectopic pregnancy as part of a heterotopic pregnancy should be attempted.

Medical management is often associated with follow-up imaging. Follow-up ultrasonography, along with follow-up beta-HCG levels, can be helpful if the diagnosis is unclear. A normal intrauterine pregnancy should demonstrate a 48-hour beta-HCG doubling time.4

Magnetic resonance imaging (MRI) has been used as a problem-solving tool in patients in stable condition and with special circumstances.

Active research continues in an attempt to elucidate an ectopic-specific serum marker. Multiple markers show some diagnostic benefit in attempting to discriminate an ectopic pregnancy from a normal intrauterine gestation; however, their use is still widely in the investigative stage. Some of the many markers investigated include progesterone, cancer antigen-125 (CA-125), pregnancy-associated plasma protein A (PAPP-A), and activin A.10,11

Related eMedicine topics:

 Bedside Ultrasonography, First-Trimester Pregnancy

Surgical Management of Ectopic Pregnancy

Limitations of Techniques

TA and EV ultrasonography are recommended in all studies. In a patient in stable condition, a full bladder should be present as a proper TA ultrasonography window. In unstable patients in whom an expeditious diagnosis is needed, the time delay for the bladder to fill may be undesirable. TA and/or EV ultrasonography may be performed in these patients with an empty bladder.

Both TA and EV examinations should still be performed with the acknowledgment of the limited, yet important, aspects of the TA portion of the examination. TA examination enables better evaluation of the superior uterus and superiorly positioned adnexa. It may aid detection of free peritoneal fluid and/or hemorrhage beyond the cul-de-sac.12

Transvaginal examination provides a detailed evaluation of the endometrial cavity and ovaries, but the high-frequency transducer that allows improved near-field resolution compared with TA examinations suffers from limited sound penetration (far-field imaging).

MRI examination is time consuming and costly. Computed tomography (CT) scan findings are nonspecific in ectopic pregnancies and pose a hazard of ionizing radiation, which may be harmful to normal pregnancies.

Differential Diagnoses

Other Problems to Be Considered

Missed abortion or blighted ovum
Normal, early intrauterine pregnancy

More on Ectopic Pregnancy

Overview: Ectopic Pregnancy
Imaging: Ectopic Pregnancy
Follow-up: Ectopic Pregnancy
Multimedia: Ectopic Pregnancy
References
Further Reading
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References

  1. Centers for Disease Control and Prevention. Ectopic pregnancy--United States, 1990-1992. MMWR Morb Mortal Wkly Rep. Jan 27 1995;44(3):46-8. [Medline]. [Full Text].

  2. Rumack CM. Ectopic pregnancy. In: Rumack CM, Wilson SR, Charboneau JW eds. Diagnostic Ultrasound. 2nd ed. St. Louis, Mo: CV Mosby; 1998:998-1004.

  3. Molinaro TA, Barnhart KT. Ectopic pregnancies in unusual locations. Semin Reprod Med. Mar 2007;25(2):123-30. [Medline].

  4. Botash RJ, Spirt BA. Color Doppler imaging aids in the prenatal diagnosis of congenital diaphragmatic hernia. J Ultrasound Med. Jun 1993;12(6):359-61. [Medline].

  5. Filly RA. Ectopic pregnancy. In: Callen PW, ed. Ultrasonography in Obstetrics and Gynecology. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1988:447-52.

  6. Alsunaidi M. Incidence of ectopic pregnancy after assisted reproduction treatment. Saudi Med J. Apr 2007;28(4):590-2. [Medline].

  7. Albayram F, Hamper UM. First-trimester obstetric emergencies: spectrum of sonographic findings. J Clin Ultrasound. Mar-Apr 2002;30(3):161-77. [Medline].

  8. Walker JJ. Ectopic pregnancy. Clin Obstet Gynecol. Mar 2007;50(1):89-99. [Medline].

  9. Maymon R, Halperin R, Mendlovic S, et al. Ectopic pregnancies in caesarean section scars: the 8 year experience of one medical centre. Hum Reprod. Feb 2004;19(2):278-84. [Medline]. [Full Text].

  10. Katsikis I, Rousso D, Farmakiotis D, et al. Receiver operator characteristics and diagnostic value of progesterone and CA-125 in the prediction of ectopic and abortive intrauterine gestations. Eur J Obstet Gynecol Reprod Biol. Apr 1 2006;125(2):226-32. [Medline].

  11. Florio P, Severi FM, Bocchi C, et al. Single serum activin a testing to predict ectopic pregnancy. J Clin Endocrinol Metab. May 2007;92(5):1748-53. [Medline]. [Full Text].

  12. Hertzberg BS, Kliewer MA, Bowie JD. Sonographic evaluation for ectopic pregnancy: transabdominal scanning of patients with nondistended urinary bladders as a complement to transvaginal sonography. AJR Am J Roentgenol. Sep 1999;173(3):773-5. [Medline]. [Full Text].

  13. Outwater EK, Siegelman ES, Chiowanich P, et al. Dilated fallopian tubes: MR imaging characteristics. Radiology. Aug 1998;208(2):463-9. [Medline]. [Full Text].

  14. Condous GS. Ultrasound diagnosis of ectopic pregnancy. Semin Reprod Med. Mar 2007;25(2):85-91. [Medline].

  15. Hertzberg BS, Kliewer MA, Bowie JD. Adnexal ring sign and hemoperitoneum caused by hemorrhagic ovarian cyst: pitfall in the sonographic diagnosis of ectopic pregnancy. AJR Am J Roentgenol. Nov 1999;173(5):1301-2. [Medline]. [Full Text].

  16. Gurel S, Sarikaya B, Gurel K, Akata D. Role of sonography in the diagnosis of ectopic pregnancy. J Clin Ultrasound. Nov-Dec 2007;35(9):509-17. [Medline].

  17. Sawyer E, Jurkovic D. Ultrasonography in the diagnosis and management of abnormal early pregnancy. Clin Obstet Gynecol. Mar 2007;50(1):31-54. [Medline].

  18. Frates MC, Laing FC. Sonographic evaluation of ectopic pregnancy: an update. AJR Am J Roentgenol. Aug 1995;165(2):251-9. [Medline]. [Full Text].

  19. Wherry KL, Dubinsky TJ, Waitches GM, Richardson ML, Reed S. Low-resistance endometrial arterial flow in the exclusion of ectopic pregnancy revisited. J Ultrasound Med. Apr 2001;20(4):335-42. [Medline].

  20. Dart R, McLean SA, Dart L. Isolated fluid in the cul-de-sac: how well does it predict ectopic pregnancy?. Am J Emerg Med. Jan 2002;20(1):1-4. [Medline].

  21. Yang SB, Lee SJ, Joe HS, et al. Selective uterine artery embolization for management of interstitial ectopic pregnancy. Korean J Radiol. Mar-Apr 2007;8(2):176-9. [Medline]. [Full Text].

  22. Rodriguez L, Takacs P, Kang J. Single-dose methotrexate for the management of interstitial ectopic pregnancy. Int J Gynaecol Obstet. Mar 2004;84(3):271-2. [Medline].

  23. Raughley MJ, Frishman GN. Local treatment of ectopic pregnancy. Semin Reprod Med. Mar 2007;25(2):99-115. [Medline].

  24. American College of Emergency Physicians. ACEP emergency ultrasound guidelines-2001. Ann Emerg Med. Oct 2001;38(4):470-81. [Medline].

  25. American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 3. Medical management of tubal pregnancy. December 1998. Clinical management guidelines for obstetrician-gynecologists. Int J Gynaecol Obstet. Apr 1999;65(1):97-103. [Medline].

  26. Atri M, Chow CM, Kintzen G, et al. Expectant treatment of ectopic pregnancies: clinical and sonographic predictors. AJR Am J Roentgenol. Jan 2001;176(1):123-7. [Medline]. [Full Text].

  27. Barnhart KT, Gosman G, Ashby R, Sammel M. The medical management of ectopic pregnancy: a meta-analysis comparing "single dose" and "multidose" regimens. Obstet Gynecol. Apr 2003;101(4):778-84. [Medline].

  28. Jung SE, Byun JY, Lee JM, et al. MR imaging of maternal diseases in pregnancy. AJR Am J Roentgenol. Dec 2001;177(6):1293-300. [Medline]. [Full Text].

  29. Kataoka ML, Togashi K, Kobayashi H, et al. Evaluation of ectopic pregnancy by magnetic resonance imaging. Hum Reprod. Oct 1999;14(10):2644-50. [Medline]. [Full Text].

  30. Kochanek KD, Hudson BL. Advance Report of Final Mortality Statistics, 1992 (corrected and reprinted). Monthly Vital Statistics Report. Vol 46, no. 6, suppl. Hyattsville, MD: Centers for Disease Control and Prevention, National Center for Health Statistics; March 22, 1995. 1-75. [Full Text].

  31. Mueller MD, Raio L, Spoerri S, et al. Novel placental and nonplacental serum markers in ectopic versus normal intrauterine pregnancy. Fertil Steril. Apr 2004;81(4):1106-11. [Medline].

  32. Nagayama M, Watanabe Y, Okumura A, et al. Fast MR imaging in obstetrics. Radiographics. May-Jun 2002;22(3):563-80; discussion 580-2. [Medline]. [Full Text].

  33. Nishino M, Hayakawa K, Kawamata K, Iwasaku K, Takasu K. MRI of early unruptured ectopic pregnancy: detection of gestational sac. J Comput Assist Tomogr. Jan-Feb 2002;26(1):134-7. [Medline].

  34. Outwater EK, Talerman A, Dunton C. Normal adnexa uteri specimens: anatomic basis of MR imaging features. Radiology. Dec 1996;201(3):751-5. [Medline]. [Full Text].

  35. Stead LG, Behera SR. Ectopic pregnancy. J Emerg Med. Feb 2007;32(2):205-6. [Medline].

  36. Yoden E, Imajo Y, Yamauchi H, Kohno I. Ectopic pregnancy showing interesting findings on MR imaging. AJR Am J Roentgenol. Mar 2001;176(3):818-9. [Medline]. [Full Text].

  37. Zinn HL, Cohen HL, Zinn DL. Ultrasonographic diagnosis of ectopic pregnancy: importance of transabdominal imaging. J Ultrasound Med. Sep 1997;16(9):603-7. [Medline].

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Further Reading

Clinical guidelines:

Undifferentiated vaginal bleeding/abdominal pain suggestive of ectopic pregnancy clinical pathway. Maine Medical Center, Department of Emergency Medicine - Hospital/Medical Center.  2006 Aug.  Various pagings.  NGC:005248

Medical management of ectopic pregnancy. American College of Obstetricians and Gynecologists - Medical Specialty Society.  1998 Dec (revised 2008 Jun).  7 pages.  NGC:006533

Clinical studies:
Two-Dose Methotrexate for Ectopic Pregnancy

Ectopic Pregnancy Biomarkers

Risk Factors of Ectopic Pregnancy

Evaluation of Therapeutic Strategies for Treatment of Ectopic Pregnancies (EP) and Evaluation of Subsequent Fertility

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Keywords

ectopic pregnancy, ectopic gestation, extrauterine gestation, heterotopic pregnancy, metacyesis, eccyesis, interstitial ectopic, cornual ectopic, cervical ectopic, fimbrial ectopic, ovarian ectopic, ovarian pregnancy, peritoneal ectopic, tubal pregnancy, abdominal pregnancy, pelvic inflammatory disease

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Contributor Information and Disclosures

Author

Douglas Bourgon, MD, Diagnostic Radiologist, Image Guided Therapeutics
Douglas Bourgon, MD is a member of the following medical societies: American College of Radiology, American Medical Association, American Roentgen Ray Society, and Radiological Society of North America
Disclosure: Nothing to disclose.

Coauthor(s)

Eric Outwater, MD, Professor, Department of Radiology, University of Arizona
Eric Outwater, MD is a member of the following medical societies: American College of Radiology, Phi Beta Kappa, and Radiological Society of North America
Disclosure: Nothing to disclose.

Gregory J Balmforth, MD, Staff Physician, Department of Diagnostic Radiology, University of Arizona Medical Center
Disclosure: Nothing to disclose.

Medical Editor

Harris L Cohen, MD, FACR, Vice Chairman/Associate Chairman (Research Activities), Director, Division of Body Imaging, Professor of Radiology, Stony Brook School of Medicine; Visiting Professor of Radiology, Johns Hopkins School of Medicine
Harris L Cohen, MD, FACR is a member of the following medical societies: American College of Radiology, American Institute of Ultrasound in Medicine, Association of Program Directors in Radiology, Radiological Society of North America, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound
Disclosure: Nothing to disclose.

Pharmacy Editor

Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.

Managing Editor

Karen L Reuter, MD, FACR, Professor, Department of Radiology, Lahey Clinic Medical Center
Karen L Reuter, MD, FACR is a member of the following medical societies: American Association for Women Radiologists, American College of Radiology, American Institute of Ultrasound in Medicine, American Roentgen Ray Society, and Radiological Society of North America
Disclosure: Nothing to disclose.

CME Editor

Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute
Robert M Krasny, MD is a member of the following medical societies: American Roentgen Ray Society and Radiological Society of North America
Disclosure: Nothing to disclose.

Chief Editor

Eugene C Lin, MD, Consulting Radiologist, Virginia Mason Medical Center; Clinical Assistant Professor of Radiology, University of Washington School of Medicine
Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear Medicine, American College of Radiology, Radiological Society of North America, and Society of Nuclear Medicine
Disclosure: Nothing to disclose.

 
 
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