Ectopic pregnancy

Background

Normal female anatomy with uterus highlighted.
  • Leading cause of maternal death in first trimester and overall third leading cause of maternal death
  • Occur in 2% of all pregnancies[1] and as high as 6-16% in those presenting to the ED[2]
  • Pregnancy in patient with prior tubal ligation or IUD in place is ectopic until proven otherwise (25-50% are ectopic)
  • Even if an IUP is visualized, there is a small risk of heterotopic ectopic pregnancy
    • General Population = 1 per 4000
    • IVF Population = 1 per 100

Risk Factors[3][4]

Risk factors absent in almost half of patients

Risk Factor Odds Ratio
Previous tubal surgery 21
Previous ectopic pregnancy 8.3
Diethylstilbestrol exposure 5.6
Previous PID 2.4 to 3.7
Assisted Fertility 2 to 2.5
Smoker 2.3
Previous intrauterine device use 1.6

Specific Types by Location

Most common location is the ampulla of the fallopian tube

Cervical Ectopic

  • Very rare with delayed diagnoses due to decreased accuracy of US
  • As high as 10% with reproductive IVF

Interstitial Ectopic

  • Typically presents after 8 wks, with rupture possibly occurring as early as 5 wks
  • Implantation in myometrium in proximal part of fallopian tube, commonly misdiagnosed on ultrasound as intrauterine pregnancy
  • 65% diagnosis on ultrasound and laparascopy is gold standard
  • US characteristics:
    • Empty uterus
    • Gestational sac separate from endometrium
    • Gestational sac > 1 cm from lateral aspect of uterine cavity
    • < 5 mm mantle surrounding the sac

Clinical Features

Must consider in all women of childbearing age with abdominal and/or pelvic pain

Differential Diagnosis

Vaginal Bleeding in Pregnancy (<20wks)

Acute Pelvic Pain

Differential diagnosis of acute pelvic pain

Gynecologic/Obstetric

Genitourinary

Gastrointestinal

Musculoskeletal

Vascular

Evaluation

Ultrasound shows ectopic pregnancy[6]
Algorithm for the Evaluation of Suspected Ectopic Pregnancy

Work-Up

Diagnostic Algorithm

Using this algorithm should always favor considering ectopic if there is any evolution or change in a patient's clinical exam[8]

Estimating the Risk for Ectopic Pregnancy[9]
Clinical Signs and Symptoms Risk Group Percent Risk of Ectopic (%)
Peritoneal irritation or cervical motion tenderness High 29
No fetal heart tones; no tissue at cervical os; pain present Intermediate 7
Fetal heart tones or tissue at cervical os; no pain <1

Step one

  • Assess for Shock
    • Beware that paradoxical bradycardia can be present with significant hemoperitoneum[10]
  • If patient is a high risk for ectopic based on above estimation then immediately contact OBGYN

Step Two

Perform a Pelvic US

  • Consider Transabdominal Ultrasound for B-HCG: >6000 mIU/ml (but if negative or indeterminate must do Pelvic ultrasound regardless of B-HCG)

Is there an Intrauterine Pregnancy?

  • If there is an IUP and there was no assisted reproductive fertility used then ectopic ruled out and heterotopic unlikely (less than 1:30,000)[11]
  • If fertility assistance was used then still consider a heterotopic (1% risk)[12]

Step Three

  • If HCG above Discriminatory Zone (>1,500-3,000 mIU/ml) and not visualized it should be an ectopic pregnancy until proven otherwise

Step Four

  • Arrange close follow-up for patients with no visualized IUP and B-HCG( (<1,500-3,000 mIU/ml), with minimal to no pain and hemodynamically stable.
  • Patients should have a 48hr repeat B-HCG level checked to determine if appropriate doubling is occurring.

Repeat B-hCG Levels

Pregnancy Type B-hCG Change
Normal
  • Increase >53% in 48hrs (until 10,000 mIU/ml)
  • Depends on the initial value:
    • <1500 --> 50% increase
    • 1500-3000 --> 40% increase
    • > 3000 --> 30% increase
Ectopic
  • Increases or decreases slowly ("plateau")^
Miscarriage
  • Decreases >20% in 48 hrs

^Initial level CANNOT be used to rule-out ectopic

Management

  1. RhoGAM for all Rh-negative women
  2. OB/GYN Consult
  3. Medical management with methotrexate (ACOG)
    • Single dose regimen[13]
    • Absolute contraindications
      • Breast-feeding
      • Laboratory evidence of immunodeficiency
      • Preexisting blood dyscrasias (bone marrow hypoplasia, leukopenia, thrombocytopenia, or clinically significant anemia)
      • Known sensitivity to methotrexate
      • Active pulmonary disease
      • Peptic ulcer disease
      • Hepatic, renal, or hematologic dysfunction
      • Alcoholism
      • Alcoholic or other chronic liver disease
      • Coexistant viable IUP
      • Does not have timely access to medical institution, or unwilling/unable to comply with post-MTX monitoring
    • Relative contraindications
      • Adnexal mass >3.5 cm in largest diameter
      • Presence of fetal heart rate
      • Free fluid visualized in Pouch of Douglas
      • Beta-HCG >5000mIU/mL
    • Note: Need to counsel patient to return after 4 and 7 days to recheck hCG values to check for satisfactory decline
    • Also note that 30-60% of women experience "separation pain" ~1 week after starting methotrexate[14]
      • Thought to be due to tubal distention from tubal abortion or hematoma formation
      • Nevertheless, presentation of abdominal pain at this time still warrants an US to look for tubal rupture, which may be indicated by increase in pelvic free fluid, decrease in Hb
      • Size of ectopic mass may actually increase before involution, and this is not associated with treatment failure
  4. Surgical treatment
    • Urgent laparotomy if patient is unstable
    • Otherwise, laparascopic salpingectomy or salpingostomy can be done

Disposition

  • Most are admitted and/or go to the OR
  • Smaller, minimally symptomatic ectopic pregnancies being treated with methotrexate may be discharged in consultation with OB/GYN

See Also

External Links

References

  1. Centers for Disease Control and Prevention. Current trends ectopic pregnancy - United States, 1990-92. MMWR Morb Mortal Wkly Rep. 1995; 44:46-48.
  2. Houry D and Keadey M. Complications in pregnancy part I: Early pregnancy. EBM. 2007; 9(6):1-28.
  3. Ankum WM, Mol BW, Van der Veen F, Bossuyt PM. Risk factors for ectopic pregnancy: a meta-analysis. Fertil Steril. 1996;65:1093–9
  4. Mol BW, Ankum WM, Bossuyt PM, Van der Veen F. Contraception and the risk of ectopic pregnancy: a meta-analysis. Contraception. 1995;52:337–41.
  5. Norris DL, Young JD. UTI. EM Clin N Am. 2008; 26:413-30.
  6. http://www.thepocusatlas.com/obgyn/
  7. Lozeau AM, Potter B. Diagnosis and management of ectopic pregnancy. Am Fam Physician. 2005;72;1707-1714, 1719-1720
  8. American College of Obstetricians and Gynecologists. Medical management of tubal pregnancy. Number 3, December 1998. Clinical management guidelines for obstetricians-gynecologists. Int J Gynaecol Obstet. 1999;65:97–103
  9. Buckley RG, King K et. al. History and physical examination to estimate the risk of ectopic pregnancy: validation of a clinical prediction model. Ann Emerg Med. 1999;34:589–94
  10. Hick JL, et al. Vital signs fail to correlate with hemoperitoneum from ruptured ectopic pregnancy. The American Journal of Emergency Medicine. 2001; 19(6)488–491.
  11. Mukul LV, Teal SB. Current management of ectopic pregnancy. Obstet Gynecol Clin N Am. 2007; 34:403-419.
  12. Yeh HC, Goodman JD, Carr L, et al. Intradecidual sign: a ultrasound criterion of early intrauterine pregnancy. Radiology. 1986;161:463-467
  13. Bachman EA and Barnhart K. Medical Management of Ectopic Pregnancy: A Comparison of Regimens. Clin Obstet Gynecol. 2012 Jun; 55(2): 440–447.
  14. Lipscomb GH et al. Management of separation pain after single-dose methotrexate therapy for ectopic pregnancy. Obstet Gynecol. 1999 Apr;93(4):590-3.