Ectopic pregnancy

Definition

• Implantation of a fertilized ovum outside the uterus

Etiology

• Failure of tubal transport of the egg
• Often results from infection
• Sites of implantation
  • Tubal (95%), especially ampulla
  • Interstitial/cornual (2-4%)
  • Ovarian, abdominal, cervical (all <1%)

Differential diagnosis

• Urogynecological
  • Abortion
  • Ruptured corpus outrun cyst
  • Ovarian torsion
  • UTI
• Non-urogynecological
  • Pyelonephritis
  • Pancreatitis
  • Appendicitis

Epidemiology

• 2% of all pregnancies
• Increasing prevalence around the world, likely due to improved detection

Risk factors

• Previous tubal surgery
• Pelvic inflammatory disease
• Previous ectopic
• IUD?
• IVF
• DES exposure
• STIs
• Contraception with high risk of ectopic

Clinical Presentation

• Spotting or bleeding
• Missed menses
• Pain, often unilateral
• Abdominal tenderness +/- adnexal mass
• Building cul-de-sac

Investigations

• Beta-hCG

  • 1500: check for gestational sac

  • <1500: repeat with ultrasound
• Abdominal +/- transvaginal ultrasound
  • Adnexal ring sign
  • Ring of fire
  • Pseudogestational sac sometimes seen in uterus, but has irregular borders and no blood flow
• Progesterone, possibly <5: ectopic or non-viable pregnancy
  • 5-25: indeterminate

  25: excludes ectopic

• Exploratory laparotomy, if necessary

Complications

• Rupture
  • Presents with increased pain, shock, hypotension, shoulder pain
• Secondary abdominal implantation
• Hemorrhage
• Death

Management

• If non-viable fetus, BhCG<15000, no contraindications, and can guarantee appropriate follow up
  • Methotrexate IM
  • Follow BhCG on days 4-7
  • Ideally for <6 weeks gestation and <3.5cm
• Otherwise, and especially if hemodynamically unstable
  • Convert a diagnostic laparotomy into a therapeutic