Data regarding the reproductive safety of benzodiazepines has always been somewhat difficult to understand. While earlier studies suggested an increased risk of cleft lip and/or palate in children exposed to benzodiazepines during pregnancy, more recent studies have not demonstrated any increase in risk of congenital malformations. A new study from the MGH Center for Women’s Mental Health adds to our data regarding the use of benzodiazepines during pregnancy.
Using data from the MGH National Pregnancy Registry for Psychiatric Medications (NPRPM), Mercedes Szpunar, MD, PhD, Marlene Freeman, MD, and colleagues from the MGH Center for Women’s Mental Health examined the risk of major malformations after first-trimester exposure to benzodiazepines.
Data was collected from the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications which prospectively enrolls pregnant women with psychiatric illness who take one or more psychiatric medications. Participants are interviewed twice during pregnancy and at 12 weeks postpartum. The researchers identified women taking any benzodiazepine during the first trimester of pregnancy, comparing them with a group of women taking psychiatric medication(s) other than benzodiazepines during pregnancy.
From this registry, a total of 1053 women were eligible for this analysis, including a total of 151 women who had taken a benzodiazepine during the first trimester of pregnancy and a comparison group of 902 women who did not use benzodiazepines. There was no difference in risk of major malformations between the two groups. There were five major malformations in the exposure group (3.21%) and 32 in the comparison group (3.46%; odds ratio 0.92, 95% confidence interval 0.35-2.41).
Data from this ongoing pregnancy registry offers reassurance that benzodiazepines do not appear to have major teratogenic effects. The registry continues to grow in size, and the precision of relative risk estimates will improve as the number of participants increases.
National Pregnancy Registry for Psychiatric Medications
Women currently taking or planning to take any type of psychiatric medication during pregnancy may consider participating in the National Pregnancy Registry for Psychiatric Medications. (This study requires no in-person visits.)
The National Pregnancy Registry for Psychiatric Medications is dedicated to evaluating the safety of psychiatric medications such as antidepressants, ADHD medications, and atypical antipsychotics that many women take during pregnancy to treat a wide range of mood, anxiety, executive function, or psychiatric disorders. The goal of this registry is to gather information on the safety of these medications during pregnancy, as current data for many medications is limited.
Ruta Nonacs, MD PhD
Szpunar MJ, Freeman MP, Kobylski LA, Caplin PS, Gaccione P, Viguera AC, Chitayat D, Hernández-Díaz S, Cohen LS. Risk of major malformations in infants after first-trimester exposure to benzodiazepines: Results from the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications. Depress Anxiety. 2022 Dec;39(12): 751-759.