Ectopic Pregnancy

OB/GYN

Overview

Definition

Implantation of the fertilized ovum outside the uterine cavity, most commonly in the fallopian tube.

Epidemiology

Occurs in ~2% of all pregnancies. The leading cause of maternal death in the first trimester.

Etiology & Risk Factors

  • Conditions that slow or block tubal transport: Pelvic Inflammatory Disease (PID), prior ectopic, tubal surgery, endometriosis
  • IUD use (does not cause ectopic, but if pregnancy occurs with an IUD, it is more likely to be ectopic)

Clinical Symptoms

  • Classic Triad: Abdominal/pelvic pain, Vaginal bleeding, and Amenorrhea (missed period)
  • If ruptured: Severe unilateral pain, syncope, shoulder pain (Kehr's sign - from diaphragmatic irritation by hemoperitoneum), hemodynamic instability

Clinical Approach

Diagnosis

  • Urine or Serum beta-hCG: Positive
  • Transvaginal Ultrasound: Absence of intrauterine pregnancy (IUP) when beta-hCG is above the discriminatory zone (~1500-2000 mIU/mL), or direct visualization of an adnexal mass/yolk sac outside the uterus

Management

  • Hemodynamically Unstable (Ruptured): EMERGENT exploratory laparotomy or laparoscopy (Salpingectomy)
  • Hemodynamically Stable (Unruptured, mass < 3.5cm, no fetal heartbeat, hCG < 5000): Methotrexate (folic acid antagonist) to halt trophoblastic cell growth

Complications

  • Tubal rupture
  • Hemorrhagic shock and death
  • Decreased future fertility