A large-scale study published in JAMA Network has found no link between benzodiazepines use in pregnancy and subsequent autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) diagnoses in offspring. When comparing siblings, benzodiazepines use had no effect on ASD or ADHD risk, indicating that the mother’s genetics partly explained the increased risk.
Some 10–30% of pregnant women experience mental disorders, including mood or anxiety spectrum disorders, for which benzodiazepine agents are sometimes prescribed; this occurs in an estimated 1.9% of pregnancies globally.
The safety of these agents to the developing foetus and newborn has been called into question, since benzodiazepines are able to cross the placenta and have been found to be present in amniotic fluid and breast milk. The US FDA includes in the category of possible harm to the foetus.
While rodents studies have tested benzodiazepine exposure during the first trimester of pregnancy, investigations of neurodevelopmental outcomes in humans, such as ASD and ADHD, have been lacking.
One study found no significantly increased risks of ADHD symptoms or fine or greater motor deficits. Those researchers suggested the disorder resulting in benzodiazepine use might partly explain the increased risks. Maternal depressive and anxiety symptoms in pregnancy have also been linked to increased ADHD risk in children.
From the Taiwanese national health database, of over 1 .5 million children born full term who were younger than 14 years of age and followed up to 2017; 5.0% had been exposed to benzodiazepines in utero.
However, no differences were found with unexposed sibling controls during the same time frame for ADHD or ASD.
The researchers concluded that their results “challenge current assumptions of a potential association of neurodevelopmental disorders with maternal benzodiazepine use before or during pregnancy. Better identification of maternal mental health concerns, as well as possible interventions or provisions of guidance to build better nurturing and raising environments for newborns at risk, may be relevant to the prevention of adverse outcomes of neurodevelopmental disorders.”
