Ectopic Pregnancy – Quick Consult
Last Updated / Reviewed: June 2022

Key History
Key Physical Exam
Risk Factors for Ectopic Pregnancy
Differential Diagnosis
Diagnostic Testing
The Use of the Discriminatory Zone
Ultrasound Findings and What They Mean
Clinical Risk and Safety Pearls
Treatment

Key History

  • History and physical establishes diagnosis in only 50% of cases
  • Consider the diagnosis in any 1st trimester abdominal pain or vaginal bleeding
  • Classic Triad - pain, amenorrhea, and vaginal bleeding present 50% of the time
  • Abdominal pain – 95% may be mild or poorly localized
  • Sudden sharp pain may be reported with rupture
  • Generalized peritonitis pain after rupture
  • Vaginal spotting or bleeding
  • Late or delayed menses
  • Syncope
  • Shoulder pain
  • Tenesmus
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Key Physical Exam

  • Adnexal tenderness – 95%
  • Adnexal mass – 30%
  • Cervical motion tenderness – 50%
  • Bulging posterior cul-de-sac
  • Unexplained shock
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Risk Factors for Ectopic Pregnancy

  • Prior tubal surgery or tubal ligation
  • History of PID
  • Use of fertility drugs or invitro reproduction
  • Use of IUD
  • Previous ectopic
  • Prior low abdominal or gynecologic surgery
  • Increasing age (35-44 year-old women have a 3-fold increased risk compared to 15-24 year-old women)
  • Smoking
  • Current use of an IUD
  • Elective abortion in the last 1 to 2 weeks
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Differential Diagnosis

  • Salpingitis
  • Spontaneous abortion or threatened abortion
  • Tubo-ovarian abscess
  • Urinary tract disease
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Diagnostic Testing

  • Pregnancy Test – Perform a pregnancy test on all women of childbearing age with abdominal or pelvic pain or vaginal bleeding unless the patient has had a hysterectomy or is well past menopause. Do not rely on the patient’s history of regular menses, birth control, tubal ligation, or abstinence.

  • b-hCG Testing – Serum hCG values alone should not be used to diagnose an ectopic pregnancy and should be correlated with the patient’s symptoms, history, and ultrasound findings.

  • Ultrasound – Ultrasound, preferably transvaginal, is a tool to determine the presence of a viable intrauterine pregnancy (IUP) and thereby exclude ectopic pregnancy. If ultrasound shows a definite IUP and no other abnormal findings, this effectively rules out ectopic pregnancy unless the patient is at high risk for heterotopic pregnancy.
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The Use of the Discriminatory Zone

  • The “discriminatory level” is a value of b-hCG above which an IUP should reliably be seen on ultrasound. Previously suggested values of the discriminatory level were 1500 mIU/mL for transvaginal scanning and about 6000 mIU/mL for transabdominal scanning.
  • To avoid the potential for misdiagnosis and possible mistaken interruption of an IUP that a woman hopes to continue, the 2018 ACOG Bulletin #193 recommends that the value of hCG used as the discriminatory level should be conservatively high (as high as 3,500 mIU/mL). Above this level of hCG, the ultrasound landmarks of a normal intrauterine gestation should be visible.
  • Higher hCG levels are present in women with a multiple gestation and they may have hCG levels above the traditional discriminatory levels before the pregnancy can be diagnosed on ultrasound.
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Ultrasound Findings and What They Mean

  • Ultrasound evidence of a normal IUP is defined as:
    • Normal appearing, double ringed gestational sac and yolk sac
    • Fetal pole
    • Heartbeat
    (If one of these is not included in the report, there is no definite evidence of an IUP.)
  • Findings highly suggestive of an ectopic are an adnexal sac-like ring or a complex or cystic mass.
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Clinical Risk and Safety Pearls

  • Dilute urine may cause a false-negative urine pregnancy test.
  • The diagnosis of pregnancy in a woman with prior tubal sterilization should be considered an ectopic pregnancy until ruled out.
  • There is no single b-hCG level that reliably distinguishes between a normal and an ectopic pregnancy.
  • Ectopic pregnancy may be present with b-hCG below the discriminatory level. Do not use the discriminatory level to rule out the presence of an ectopic pregnancy.
  • Patients discharged with diagnosis of possible ectopic pregnancy should have precise discharge instructions regarding the time, date, and with whom to follow-up. Discharge instructions must include a plan to return to an emergency department for any significant change in condition.
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Treatment

  • Consultation with OB-GYN for established or uncertain diagnosis of ectopic pregnancy.
  • Appropriate treatment by the OB-GYN may be medical (methotrexate) or surgical.
  • If the patient is in hemorrhagic shock and the practitioner suspects ectopic pregnancy, immediate consultation for laparotomy is warranted.
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  1. American College of Obstetricians and Gynecologists Committee on Practice Bulletins–Gynecology. ACOG Practice Bulletin No. 193: Tubal Ectopic Pregnancy. Obstet Gynecol. 2018;131(3):e91-e103.
  2. Bouyer, J, Coste, J, Shojaei, T, et al. Risk factors for ectopic pregnancy: a comprehensive analysis based on a large case-control, population-based study in France. Am J Epidemiol 2003; 157:185.
  3. Clinical Policy: Critical Issues in the Initial Evaluation and Management of Patients Presenting to the Emergency Department in Early Pregnancy. Ann Emerg Med. 2017;69:241-250.
  4. Heaton H. Ectopic Pregnancy and Emergencies in the First 20 Weeks of Pregnancy. In: Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill Education; 2016.
  5. Stein JC, Wang R, Adler N, et al. Emergency physician ultrasonography for evaluating patients at risk for ectopic pregnancy: a meta-analysis. Ann Emerg Med. 2010;56:674-683.
  6. Wang R, Reynolds TA, West HH, et al. Use of a b-hCG discriminatory zone with bedside pelvic ultrasonography. Ann Emerg Med. 2011;58:12-20.

This is intended solely as reference material and is not a recommendation for any specific patient. The practitioner must rely upon his or her own professional judgment and medical decision-making to determine whether it is relevant in a particular case. Materials are derived from medical and nursing texts, medical literature and national guidelines and should not be considered complete or authoritative. Users must rely on specific patient presentation, experience and judgment when utilizing any of the information contained herein relative to an actual patient.
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