"However, for women suffering from schizophrenia, bipolar disorder, or major depressive disorder, avoiding medication use is often impossible, given that there are very few alternative treatment options," she said in a hospital news release.
But how safe is exposure to these drugs for the developing fetus?
To find out, Huybrecht's team tracked Medicaid data on 1.3 million pregnant women in order to assess the effects of older (typical) antipsychotic drugs and newer (atypical) versions, which are less likely to affect fertility.
The study focused on the most often used drugs in both classes: aripiprazole (Abilify), olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal) and ziprasidone (Geodon).
Among the women in the study, just over 700 (0.05 percent) filled a prescription for a typical antipsychotic in the first 90 days of pregnancy, and nearly 9,300 (0.69 percent) filled a prescription for an atypical antipsychotic.
Researchers reported birth defects in about 3.8 percent of babies born to women who had taken a typical antipsychotic and 4.45 percent whose mothers had taken atypical antipsychotics.
Those numbers weren't significantly different from the birth defect rate of babies whose mothers had not taken an antipsychotic drug -- 3.27 percent.
Rates of heart birth defects were similar, according to the researchers.
After controlling for other factors, the investigators found no significant increased risk for any type of birth defect among women who took either type of antipsychotic medicine (APM) in the first trimester of pregnancy. The possible exception was risperidone, which was associated with a slightly increased risk.
"Our findings help inform psychiatrists and their patients about the risk of using APMs during early pregnancy," said Huybrechts, who is an epidemiologist at the hospital and an assistant professor of medicine at Harvard Medical School.
One expert in psychology said the study should help patients.
The findings "are relatively reassuring given that two smaller and less well-controlled studies had suggested that congenital malformations were more common in the babies of women who took antipsychotic medications early in pregnancy," said Dr. Andrew Adesman. He's chief of developmental and behavioral pediatrics at Cohen Children's Medical Center in New Hyde Park, N.Y.
This "careful analysis" suggests "that most antipsychotic medications taken early in pregnancy are not likely associated with heart defects or other congenital malformations in the baby," Adesman said.
Still, more research is needed, especially when it comes to risperidone, he added. In the meantime, "women who are taking an antipsychotic medication should discuss any plans they may have to get pregnant with their physician," Adesman advised.
The study was published Aug. 17 in the journal JAMA Psychiatry.
SOURCES: Andrew Adesman, M.D., chief, developmental & behavioral pediatrics, Cohen Children's Medical Center, New Hyde Park, N.Y.; Brigham and Women's Hospital, news release, Aug. 17, 2016