PB 225: Medical Abortion Up to 70 Days of Gestation

Question 1

Mifepristone MOA

Answer 1

Selective progesterone receptor modulator that binds to the progesterone receptor with an affinity greater than progesterone itself but does NOT activate the receptor, thereby acting as an antiprogestin

Known actions on the uterus: decidual necrosis, cervical softening, increased uterine contractility and prostaglandin sensitivity

Question 2

Misoprostol MOA

Answer 2

Prostaglandin E1 analogue that causes cervical softening and uterine contractions

Question 3

Teratogenicity of misoprostol

Answer 3

Can result in congenital anomalies, such as limb defects with or without Mobius’ syndrome (ie, facial paralysis), when used during the first trimester

Question 4

Adverse effects commonly associated with misoprostol

Answer 4

• Nausea (43-66%)
• Vomiting (23-40%)
• Diarrhea (23-35%)
• Headache (13-40%)
• Dizziness (23-39%)
• Thermoregulatory effects such as fever, warmth, hot fushes, or chills (32-69%)

Question 5

What regimen is the preferred therapy for medication abortion?

Answer 5

Mifepristone (200 mg taken orally) - misoprostol (variable)

Question 6

Should prophylactic antibiotics be used in medication abortion?

Question 7

Serum hCG testing 1 week after medication abortion?

Answer 7

A serum hCG level decrease of at least 80% over 6-7 days after initiating treatment with mifepristone and misoprostol indicates a successful abortion.

Question 8

How to treat an incomplete medication abortion?

Answer 8

Can be treated with a repeat dose of misoprostol, uterine aspiration, or expectant management

Studies indicate with even with a retained sac at 2 weeks after medication abortion, intervention is unnecessary, and that expulsion will typically occur in the ensuing weeks.

Patients with incomplete medication abortion 1 week after treatment can safely receive another dose of misoprostol or repeat misoprostol doses can be used for a persistent gestational sac.