Objective: To report a case of a child born with Möbius syndrome following exposure in utero to mifepristone and misoprostol for elective abortion.
Case summary: In the seventh week of pregnancy, a woman was administered mifepristone 600 mg and, 2 days later, misoprostol 400 mug for abortion. One month later, despite significant metrorrhagia, an ultrasound examination showed ongoing gestation. At 33 weeks and 3 days of gestation, the woman gave birth to a male with left facial palsy, microretrognathia, and axial hypotonia related to Möbius syndrome.
Discussion: Möbius syndrome is characterized by unilateral or bilateral palsy of the abducens (VI) and facial (VII) cranial nerves. Other cranial nerves (eg, the hypoglossal [XII]), craniofacial or orofacial anomalies, and limb malformations are often associated. The etiology of the Möbius syndrome remains largely unknown and probably involves multiple factors. The most likely etiological hypothesis is disruption of the developing vascular system, with transient ischemia (particularly in the vertebral arteries) and fetal hypoxia. A teratogenic cause of Möbius syndrome has been suggested. The critical period for the development of Möbius syndrome following teratogen exposure appears to be 5-8 weeks of gestation. To date, mifepristone alone does not appear to have induced Möbius syndrome. In contrast, oral or vaginal misoprostol administration can lead to a significant increase in Doppler-measured uterine artery resistance and may induce uterine contractions. If these occur during the critical embryonic period, they may cause flexion in the areas of the sixth and seventh cranial nerves and decreased blood flow.
Conclusions: Ineffective use of mifepristone and misoprostol in the first trimester of pregnancy may be associated with a risk of Möbius syndrome, primarily due to misoprostol activity. Women with ongoing pregnancy after failed abortion with misoprostol administration should be informed of this risk.