A new study, published online by JAMA Network Open, analysed data from the Norwegian Mother, Father and Child cohort study (MoBa) to examine the associations of exposure to benzodiazepines and benzodiazepine-like hypnotic drugs (z-hypnotics) in pregnancy with pregnancy outcomes.
The main outcomes were gestational age at delivery, risk of preterm delivery, birth weight, birth weight relative to gestational age and sex, risk of being small for gestational age, head circumference, Apgar score
This analysis included 82,038 singleton pregnancies among 69,434 unique women. Exposure to benzodiazepines or z-hypnotics was reported in 679 pregnancies (0.8%).
After adjusting for confounders, benzodiazepine or z-hypnotic use during pregnancy was associated with lower birth weight (mean difference, −79.3 g; 95% CI -126.7 to -31.9), lower gestational age at birth (-2.1; 95% CI -3.3 to -0.9 days), and higher risk of preterm birth (risk ratio 1.41; 95% CI 1.03-1.94). There was no significant association with birth weight relative to gestational age and sex .
While the magnitudes of the associations were not necessarily clinically significant, the findings suggest benzodiazepines and z-hypnotics should only be used in pregnancy after a thorough evaluation of the benefits and risks for the mother and child.