Washington, Dec 3 (ANI): Drugs commonly prescribed for the treatment of asthma and pre-term labour in pregnant mothers might put kids at an increased autism risk, reveals a new study.

Beta 2 adrenergic agonist drugs are widely used in obstetrics as tocolytics to inhibit or slow down labour and bronchodilators, but may act as functional and behavioural teratogens when given continuously in the mid to late second or early third trimesters.

These drugs can cause functional and behavioural disorders by permanently altering the balance of sympathetic and parasympathetic tone in the individual.

The authors also offer recommendations for safe practice in obstetrics in light of the teratogenic risk posed by beta 2 adrenergic agonists.

“Given the risk of long-term neurophysiologic and behavioural impairment, the use of beta 2 adrenergic agonists should be limited to proven indications when alternate drugs are ineffective or unavailable and the risks of the untreated disease to the mother and fetus are greater than the risk of the beta 2 adrenergic agonist,” said Dr Frank R. Witter, Johns Hopkins University School of Medicine and Johns Hopkins University Bloomberg School of Public Health.

“Treatment duration should be as short as clinically feasible. Further ongoing surveillance of the use of these agents in pregnancy is needed to refine the parameters for their safe use in pregnancy,” he added.

Animal studies support the concept that in humans prenatal exposure to continuous high doses of beta 2 adrenergic agonists can permanently dysregulate signaling from the beta 2 adrenergic receptor.

The study is published in American Journal of Obstetrics & Gynecology. (ANI)