New study suggests antipsychotic use not linked to birth defects

A major study of 1.3 million women has suggested that antipsychotic use during pregnancy does not significantly increase the risk of birth defects.

The research, carried out at Harvard Medical School, also found that there was no enhanced risk of cardiac malformations in particular.

Exposure to antipsychotics during pregnancy is increasingly common, said the researchers. Antipsychotic medications are used for some types of mental distress or disorder such as schizophrenia or bipolar disorder, or used with antidepressants to treat depression.
According to the researchers, the decision for pregnant women to take antipsychotic medication is stems from the belief that the overall negative impact of the disease is greater than that of the drug treatment.

Little is known regarding the safety of APs on the developing fetus, however, and concerns have previously been raised about a potential association between antipsychotics and congenital malformations. The latest study, published in JAMA Psychiatry, examined the risk of congenital and cardiac malformations associated with first-trimester exposure to antipsychotics.

Researchers at the Division of Pharmacoepidemiology and Pharmacoeconomics at Brigham and Women's Hospital and Harvard Medical School, and co-authors used a nationwide Medicaid database sample of over 1.3 million pregnant women.

Exposure to antipsychotics was defined as filling at least one prescription during the first trimester of pregnancy and individual drugs including aripiprazole, olanzapine, quetiapine fumarate, risperidone, and ziprasidone were assessed.

According to the results, among the more than 1.3 million women, 9,258 women (0.69 percent) filled a prescription for an atypical AP, and 733 women (0.05 percent) filled a prescription for a typical AP during the first trimester. The most frequently used atypical APs in order of frequency were quetiapine, aripiprazole, risperidone, olanzapine, and ziprasidone.

The researchers found little difference in outcomes between women who had taken an antipsychotic compared with those who hadn’t. It was seen that 4.45 percent of births exposed to atypical APs and 3.82 percent of births exposed to typical APs were associated with congenital malformations, compared with 3.27 percent of births to women who did not fill a prescription for an antipsychotic. Similar findings were noted for cardiac malformations.

A small increase in absolute risk and relative risk for birth defects was observed with risperidone but the authors state that this should be interpreted with caution because there is no clear biological mechanism to suggest why, and the possibility of a chance finding cannot be ruled out.

“Our findings suggest that use of antipsychotics early in pregnancy does not meaningfully increase the risk for congenital malformation or cardiac malformation, with the possible exception of risperidone,” concluded the authors.

Photo credit: Vanessa Porter, used under the Creative Commons license.

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