How is a blighted ovum (anembryonic pregnancy) typically managed?

Management of Anembryonic Pregnancy (Blighted Ovum)

Anembryonic pregnancy should be managed with one of three options: expectant management, medical management with misoprostol, or surgical management with suction dilation and curettage (D&C), with the choice depending on patient preference, clinical stability, and gestational age. 1

Diagnosis and Terminology

• The preferred term is "anembryonic pregnancy" rather than "blighted ovum," defined as a gestational sac measuring ≥25 mm without an embryo, or absence of an embryo on serial ultrasound examinations 1
• Diagnosis is made via transvaginal ultrasound using specific criteria: mean sac diameter ≥25 mm with no embryo, or absence of embryo ≥14 days after visualization of gestational sac 1, 2
• Quantitative hCG measurements should be used to confirm declining levels and eventual resolution 2

Management Options

1. Expectant Management

• Involves waiting for spontaneous passage of pregnancy tissue 1
• Success rates vary depending on gestational age and time from diagnosis 1
• Appropriate for hemodynamically stable patients who prefer minimal intervention 1

2. Medical Management

• Recommended for patients who wish to avoid surgery but desire faster resolution than expectant management 1
• Misoprostol is the medication of choice 1, 2
• Particularly useful for incomplete miscarriages 2

3. Surgical Management (D&C)

• Indicated for patients with:
  • Hemodynamic instability
  • Significant bleeding
  • Signs of infection 1
• Should be performed under ultrasound guidance to reduce risk of uterine perforation 2
• Uterotonic agents should be administered during and after the procedure to reduce bleeding risk 2

Follow-up and Monitoring

• Serial hCG monitoring until levels return to non-pregnant state 1, 2
• Ultrasound evaluation to confirm complete evacuation of products of conception 1, 2
• Histopathologic examination of tissue is recommended to:
  • Confirm intrauterine pregnancy
  • Rule out gestational trophoblastic disease 1, 2
• Blood type and Rh status should be assessed, with Rho(D) immunoglobulin administered to Rh-negative women 2

Complications to Monitor

• Risk of infection increases with time after diagnosis, particularly after 18 hours 1, 3
• Hemorrhage is a potential complication, especially with incomplete evacuation 1
• Warning signs requiring immediate intervention include:
  • Fever >100.4°F (38.0°C)
  • Uterine tenderness
  • Purulent vaginal discharge 3

Common Pitfalls to Avoid

• Using outdated terminology like "blighted ovum" can be hurtful to patients 1
• Failing to confirm complete evacuation of products of conception can lead to complications 1
• Overlooking the possibility of heterotopic pregnancy (though rare in spontaneous conceptions) 4
• Inadequate follow-up after management, which is essential to ensure resolution 1, 2

Special Considerations

• Advanced maternal age is a risk factor for anembryonic pregnancy 5
• Low β-HCG levels are associated with increased risk of anembryonic pregnancy 5
• No specific waiting period is required before attempting pregnancy after management of anembryonic pregnancy, though many clinicians traditionally recommend waiting 1-3 menstrual cycles 6