Prenatal exposure to anxiolytics and hypnotics and language competence at 3 years of age

The aim of the study was to examine if there was an association between use of anxiolytics and hypnotics in pregnancy and language competence in the offspring at age 3 years.

The Norwegian Mother and Child Cohort Study (MoBa) is a prospective pregnancy cohort where the mothers were asked to report on their medication use at pregnancy week 17-18, 30, and at 6 months postpartum. A woman was defined as a user of anxiolytics and hypnotics during pregnancy if she had reported use of benzodiazepines or benzodiazepine-related drugs during pregnancy. Children's language competence was measured at age three by maternal report on a validated language grammar scale. We used ordinal logistic regression with estimated standard errors allowing for clustering of multiple pregnancies.

Forty-five thousand and two hundred sixty-six women with 51,748 pregnancies were included in the study. The women reported use of anxiolytics and/or hypnotics in 395 pregnancies (0.8 %). The odds ratios of being in a group with lower language competence were 1.2 (0.9-1.5) and 1.7 (1.0-2.8) for short-term and long-term anxiolytics and hypnotics use, respectively. When adjusting for SSRI use during pregnancy, the odds ratios were 1.1 (0.83-1.41) and 1.4 (0.84-2.33), respectively. Children whose mothers took no anxiolytics and hypnotics during or before pregnancy were reference group.

The results refute any strong association between prenatal use of anxiolytics and hypnotics and lower language competence in the offspring at age 3 years.