Ectopic pregnancy

Background

• Must consider in all women of childbearing age who p/w abd/pelvic pain + hypovolemia
• Leading cause of maternal death in first trimester
• Pregnancy in patient with prior tubal ligation or IUD in place is ectopic until proven otherwise (25-50% are ectopic)
• Heterotopic risk
  • General Population = 1 per 4000
  • IVF Population = 1 per 100

Risk Factors

Risk Factors associated with Ectopic Pregnancy

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

Work-Up

1. Hb (or CBC)
2. Beta-HCG (quantitative)
3. Type and Screen with Rh Factor
4. FAST and Pelvic US

Diagnosis

Clinical Features

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

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
• 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 US 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 followup 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

• 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

DDX

1. All Patients
   1. Appendicitis
   2. IBD
   3. Ovarian Cyst
   4. Ovarian Torsion
   5. PID
   6. Endometriosis
   7. Sexual assault/trauma
   8. Urinary Tract Infection
   9. Ureteral Colic
2. Pregnant Patients
   1. Normal (intrauterine pregnancy)
   2. Threatened abortion
   3. Inevitable abortion
   4. Molar pregnancy
   5. Heterotopic pregnancy
   6. Implantation bleeding
   7. Corpus luteum cyst

Treatment

1. RhoGAM for all Rh- pts
2. OB/GYN Consult
3. Medical management with methotrexate (ACOG)
   1. Absolute contraindications
      1. Breast-feeding
      2. laboratory evidence of immunodeficiency
      3. preexisting blood dyscrasias (bone marrow hypoplasia, leukopenia, thrombocytopenia, or clinically significant anemia)
      4. known sensitivity to methotrexate
      5. active pulmonary disease; peptic ulcer disease
      6. hepatic, renal, or hematologic dysfunction
      7. alcoholism
      8. alcoholic or other chronic liver disease
   2. Relative contraindications
      1. Ectopic mass >3.5 cm
      2. Embryonic cardiac motion
   3. Regimen choice
      1. hCG value <5000 mIU/ml --> single dose
      2. hCG value >5000 mIU/ml --> multi dose
4. OR, Surgery
   1. Salpingectomy vs. salpingostomy

External Links

• MDCalc - Pregnancy Due Dates Calculation

Source

• Barnhart KT. Ectopic Pregnancy [clinical practice]. N Engl J Med. 2009;361(4):379-387.