Study examines link between antipsychotic treatment during pregnancy and gestational diabetes risk

An increasing number of women are treated with antipsychotic drugs during pregnancy even though safety questions remain unanswered. Certain antipsychotic drugs used to treat bipolar disorder, schizophrenia, and other severe mental health disorders have previously been shown to have metabolic side effects, including weight gain and diabetes, in the general population. Whether the continued use of such antipsychotic medications during pregnancy may lead to an increased risk of gestational diabetes was not known.

Researchers from Brigham and Women's Hospital, Harvard Medical School, Harvard School of Public Health and Massachusetts General Hospital addressed the link between antipsychotic treatment during pregnancy and gestational diabetes in a new research paper published online today by the American Journal of Psychiatry.

Quantifying this risk was important, as approximately 50 percent of women who have gestational diabetes will develop type 2 diabetes in the years following pregnancy. Gestational diabetes is also associated with adverse pregnancy outcomes, including preeclampsia, cesarean delivery, neonatal hypoglycemia, and macrosomia.

The study examined the risk of developing gestational diabetes associated with continued use of several antipsychotic medications during pregnancy. The researchers focused on five atypical antipsychotics: aripiprazole, ziprasidone, quetiapine, risperidone, and olanzapine. Continuation of olanzapine and quetiapine showed an increased risk for gestational diabetes compared with women who discontinued these medications. Aripiprazole, ziprasidone, and risperidone during pregnancy was not associated with an increased risk of gestational diabetes. The study included women without pre-existing diabetes who received antipsychotic drugs during the three months before pregnancy, and compared women who continued to take medication during the first half of pregnancy to those who stopped during pregnancy.

"The risks of gestational diabetes observed during pregnancy are in line with expectations based on the metabolic side effects observed in the general population," said senior author Krista F. Huybrechts, MS, PhD, an epidemiologist in the Division of Pharmacoepidemiology and Pharmacoeconomics at BWH. "Certain antipsychotics have different levels of risk of metabolic side effects."

Continuation of quetiapine led to a 28 percent increased risk, corresponding to 1.6 extra cases of gestational diabetes per 100 women treated. Continuation of olanzapine led to a 61 percent increased risk, corresponding to 4.4 extra cases of gestational diabetes per 100 women treated. The study accounted for a broad range of proxy variables. Researchers are confident that increased risks are not due to confounding by incomplete overweight or obesity measurements at the start of pregnancy.

"Clinicians must weigh the benefits of staying on a stable regimen against the risks of continuing treatment with a higher-risk atypical antipsychotic during pregnancy to make an informed decision about the best course of treatment for the patient in question," said Huybrechts.