Antipsychotics Appear to Pose Minimal Risk in Pregnancy

Beth Skwarecki

May 15, 2015

Women taking the antipsychotics quetiapine, olanzapine, or risperidone during pregnancy did not have higher rates of complications such as gestational diabetes, preterm birth, or infants with extremely high or low birth weight, according to a matched, population-based cohort study published May 13 in the BMJ.

"If a practicing clinician encounters an individual currently taking an atypical antipsychotic, who finds out that she is pregnant, [this study suggests] that you would not need to reflexively stop or change their medicine," according to Zachary Stowe, MD, from the Departments of Psychiatry, Pediatrics, and Obstetrics and Gynecology at the University of Arkansas, who was not involved in the study.

The "atypical" antipsychotic medications studied are now more common than first-generation antipsychotics. The newer drugs are considered to have a potentially higher risk for metabolic syndrome and venous thromboembolism, but this study showed no increase in those conditions among pregnant women taking atypical antipsychotics compared with among pregnant women not taking those drugs.

The researchers evaluated Canadian women who had access to hospital care and drug coverage and who gave birth to a singleton baby between April 2003 and December 2012. Of the 52,615 eligible women, 1323 were considered to be taking antipsychotics (they filled two consecutive prescriptions during pregnancy, with at least one in the first or second trimester), and 1021 could be matched, using a high dimensional propensity score, with women who did not take any antipsychotics in pregnancy. Unmatched women were older and had higher baseline medical morbidity than the women who could be matched.

Antipsychotic users had higher rates of hypertensive disorders and blood clots than the general population, but their rates were no higher than the matched cohort. Among the matched groups, women taking atypical antipsychotics did not have significantly greater risks for complications, including gestational diabetes, preterm birth, hypertensive disorders including preeclampsia, venous thromboembolism, or infants with birth weights below the third or above the 97th percentile.

Women taking antipsychotics did have higher rates of labor induction (adjusted relative risk, 1.23; 95% confidence interval [CI], 1.03 - 1.48) and operative vaginal delivery (adjusted relative risk, 1.55; 95% CI, 1.10 - 2.19). Women taking antipsychotics in the unmatched cohort, however, were at higher risk for several complications, including preterm birth before 32 weeks (relative risk, 1.61; 95% CI, 1.19 - 2.16).

"Our findings suggest that antipsychotic medication use in pregnancy poses a minimal risk for adverse outcomes for the pregnant woman and her fetus," write Simone N. Vigod, MD, from the Department of Psychiatry at the Women's College Research Institute and the Women's College Hospital at the University of Toronto, Ontario, Canada, and colleagues.

They note that because complication rates were higher in the matched cohort than in the unmatched group or in the general population, women taking antipsychotics may be in a population that is already at greater risk for these complications. It is possible, they add, that previous antipsychotic use (reported by 88% of the antipsychotic users and 27% of the matched cohort) may have influenced metabolic function before pregnancy.

Because of this elevated risk, the authors suggest close monitoring of women taking antipsychotics may be warranted, even if the drugs themselves do not appear to increase the risk of adverse outcomes.

"The study design looks like it's been done very well," Dr Stowe told Medscape Medical News. "We always have to interpret results like this fairly cautiously, but the bulk of their findings are consistent with my own clinical experience and the previous reports on this class of medicines from much smaller studies, which has not really indicated any acute assignable risk to this class of medicines."

Dr Vigod has received a one-time consulting fee from Multi-Dimensional Health Care consulting for the development of continuing healthcare activities related to perinatal mental health. Another coauthor receives funding from Bristol-Myers Squibb for an investigator-initiated study and has been a speaker for Astra-Zeneca, Bristol-Myers Squibb, Eli Lilly, and Lundbeck. The remaining authors and Dr Stowe have disclosed no relevant financial relationships.

BMJ. 2015;350:h2298. Full text


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