Misoprostol is a synthetic prostaglandin E1 analogue which acts as a potent uterine stimulant. It is used for medical termination of pregnancy following mifepristone exposure. Misoprostol is also used in monotherapy for the prophylaxis and treatment of NSAID-induced gastric ulcers, and for induction of labour.
Where ongoing pregnancy has followed exposure to misoprostol in the first trimester, case reports describe a spectrum of anomalies consistent with Möbius syndrome. Observed anomalies include cranial nerve palsies, limb defects, orofacial clefts, arthrogryposis, talipes, autism and intellectual disability. The absolute risk of malformation following misoprostol exposure is unquantified. It has been suggested that the critical period of teratogenic risk is between five and eight weeks of gestation, but this is not universally accepted.
Increased risks of intrauterine death and reduced birth weight following gestational misoprostol exposure have also been observed in some studies. Neurodevelopment has not been systematically studied in infants exposed to misoprostol. It is uncertain whether autism and neurodevelopmental anomalies are more common in individuals with Möbius syndrome following misoprostol exposure than in those with Möbius syndrome in the absence of misoprostol exposure.
Due to its abortifacient and teratogenic effects, women of childbearing potential who are using misoprostol for the prophylaxis and treatment of NSAID-induced gastric ulcers should be counselled on the importance of effective contraception. Pregnancy should be excluded before treatment is initiated.
Additional monitoring of fetal viability, growth and development is likely to be indicated in ongoing pregnancies with misoprostol exposure. It should be noted that cranial nerve defects are unlikely to be detected by ultrasound examination but should be suspected if limb anomalies or arthrogryposis are observed. Other risk factors may also be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.
This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to NHS health care professionals who are logged in.
If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.
If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.