In Western countries, macrolide antibiotics are among the most-prescribed types of antibiotics for pregnant women. However, recent research indicates the adverse effects of macrolide antibiotics during pregnancy on offspring. The objective of this study is to evaluate the association between prescribing macrolide antibiotics during pregnancy and adverse child outcomes.

This is a population-based cohort study that included 104,605 children born to mothers who were prescribed one macrolide or penicillin monotherapy from their fourth gestational week to delivery. The primary outcome was the risk of any major malformations, epilepsy, cerebral palsy, autism disorder, or attention deficit hyperactivity disorder in children.

The researchers discovered major malformations, especially cardiovascular malformations, in 186 of 8,632 children of mothers who were prescribed macrolides and 1,666 of 95,973 children of mothers who were prescribed penicillin. Macrolide prescribing in the first trimester was associated with major malformations when compared to penicillin. In any trimester, macrolide transformation increased the risk of genital malformations.

The research concluded that prescribing macrolide antibiotics during the first trimester of pregnancy was associated with a higher risk of major malformations. Prescribing macrolides also increased the risk of genital transformation during the third transformation. The findings thereby suggest that macrolide antibiotics should be used with caution during pregnancy.