Misoprostol and pregnancy: risk of malformations

(1) Misoprostol, a synthetic prostaglandin E1 analogue, is used to treat gastric and duodenal ulcers, and, in combination with mifepristone, for medical abortion. (2) The French and American summaries of product characteristics, based on data submitted to the relevant regulatory agencies, mention no teratogenicity in animals. However, some studies showed malformations in rats and rabbits. (3) Severe malformations have been reported in countries where misoprostol is frequently used for abortion without medical supervision despite its poor efficacy when used alone. The malformations included cranial nerve defects (especially pairs 6 and 7, characteristic of the Möbius syndrome) and various limb abnormalities. (4) Malformations, including one case of Möbius syndrome, have been reported in France after medically supervised use of misoprostol. (5) In practice, when a patient wishes to continue a pregnancy after a failed attempt at drug-induced abortion, she needs to be informed of the risk to her unborn child. Cranial nerve defects are rarely detectable by sonography, however thorough. In addition, misoprostol has a negative risk-benefit balance in the prevention or treatment of gastro-duodenal ulcers in young women.