Antipsychotics mainly safe in pregnancy

Taking antipsychotic drugs in early pregnancy does not usually increase the risk of congenital malformations, a large new study has found.

Increasing numbers of women are taking antipsychotics during pregnancy, partly because most newer ‘atypical’ antipsychotics are thought to be less likely to affect fertility than the older ‘typical’ types, researchers say.

Nevertheless, clinicians have very little information regarding the safety of these drugs for the developing foetus, say Dr Krista Huybrechts of Brigham and Women’s Hospital, Boston, USA, and colleagues.

The team examine the risk for congenital malformations overall and cardiac malformations in particular among foetuses exposed to antipsychotics in their first trimester. They used figures on 1,341,715 pregnancies over a ten-year period from 2000 to 2010.

In just under 1% of pregnancies the woman was taking an antipsychotic drug in the first trimester.

Congenital malformations were seen in 32.7 per 1,000 babies not exposed to any antipsychotics, 44.5 per 1,000 babies exposed to atypical antipsychotics, and 38.2 per 1,000 babies exposed to typical antipsychotics.

This suggests that atypical antipsychotics were linked to a 36% raised risk of malformations, but typical antipsychotics carried no statistically significant rise in risk.

"The findings for cardiac malformations were similar," the team states in JAMA Psychiatry today (17 August). They add that when looking at individual drugs, a small increased risk in overall malformations and cardiac malformations was found for the atypical antipsychotic risperidone.

"Evidence from this large study suggests that use of antipsychotics early in pregnancy generally does not meaningfully increase the risk for congenital malformations overall or cardiac malformations in particular."

But "the small increase in the risk for malformations observed with risperidone requires additional study".

Huybrechts, K. F. et al. Antipsychotic Use in Pregnancy and the Risk for Congenital Malformations. JAMA Psychiatry 17 August 2016 doi:10.1001/jamapsychiatry.2016.1520 [abstract]