Ectopic pregnancy

Background

• Leading cause of maternal death in first trimester and overall third leading cause of maternal death
• Occur in 2% of all pregnancies and as high as 6-16% in those presenting to the ED
• 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

• 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

Clinical Features

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

• Ruptured
  • Shock
  • Rebound tenderness
• Non-ruptured (early)
  • Abdominal/pelvic pain
  • Vaginal bleeding

Differential Diagnosis

Vaginal Bleeding in Pregnancy (<20wks)

• Ectopic Pregnancy
• First Trimester Abortion
  • Complete Abortion
  • Incomplete Abortion
  • Inevitable Abortion
  • Missed Abortion
  • Septic abortion
  • Threatened Abortion
• Gestational trophoblastic disease
  • Consider when pregnancy-induced hypertension is seen before 24 wks of gestation
• Heterotopic pregnancy
• Implantation bleeding
• Molar pregnancy
• Non-pregnancy related bleeding
  • Cervicitis
  • Fibroids
  • Implantation bleeding

Pelvic Pain

Pelvic origin

• Urinary Tract Infection
• Ectopic
• Ovarian torsion
• Endometriosis
• PID
• Cervicitis
• Ectopic Pregnancy
• Ovarian Torsion
• Spontaneous abortion
• Septic abortion
• Myoma (degenerating)
• Ovarian cyst (rupture)
• Tubo-ovarian abscess
• Mittelschmerz
• Sexual assault/trauma
• Ovarian hyperstimulation syndrome

Abdominal origin

• Appendicitis
• Kidney stone
• Psoas abscess
• Mesenteric adenitis
• Incarcerated hernia
• Diverticulitis
• Pyelonephritis

Evaluation

Work-Up

• hemoglobin (or CBC)
• Beta-HCG (quantitative)
• Type and Screen with Rh Factor
• FAST and Pelvic US

Diagnostic Algorithm

Estimating the Risk for Ectopic Pregnancy

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

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

Step one

• Assess for Shock
  • Beware that paradoxical bradycardia can be present with significant hemoperitoneum
• 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)
• If fertility assistance was used then still consider a heterotopic (1% risk)

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.

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

Repeat B-hCG Levels

• Normal pregnancy
  • B-hCG should increase >53% in 48hrs (until 10,000 mIU/ml)
• Ectopic pregnancy
  • B-hCG increases or decreases slowly ("plateau")^
• Miscarriage
  • B-hCG 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
     • MTX 50mg IM day 1
     • If hCG decreases by <15% between days 4 and 7, another 50mg IM MTX on day 7
   • 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
4. Surgical treatment
   • Urgent laparotomy if patient is unstable
   • Otherwise, laparascopic salpingectomy or salpingostomy can be done

See Also

• Pregnancy (main)
• methotrexate toxicity

External Links

• MDCalc - Pregnancy Due Dates Calculation

References

Authors

Ross Donaldson, Vincent Chan, Kevin Lu, Neil Young, Christopher Mathew, Jordan Swartz, Bobak Zonnoor, Marissa Camilon, Ann Huang, Daniel Ostermayer