Major Malformations Up With Macrolide Prescribing in Pregnancy

Macrolide prescribing during any trimester linked to increased risk for genital malformations.

HealthDay News – Prescribing macrolide antibiotics during the first trimester of pregnancy is associated with an increased risk for major fetal malformation, according to a study published online February 19 in The BMJ.

Heng Fan, from University College London, and colleagues conducted a population-based cohort study including 104,605 children born from 1990 to 2016 whose mothers were prescribed one macrolide monotherapy or one penicillin monotherapy from the fourth gestational week to delivery. Two negative control cohorts were included: 82,314 children whose mothers were prescribed macrolides or penicillin before conception and 53,735 siblings of the children in the study cohort.

The researchers found that major malformations were recorded in 21.55 and 17.36 per 1000 children whose mothers were prescribed macrolides and penicillins during pregnancy, respectively. Compared with penicillin, macrolide prescribing during the first trimester was associated with an increased risk for any major malformation (adjusted risk ratio, 1.55) and specifically cardiovascular malformations (adjusted risk ratio, 1.62). Increased risk for genital malformations was seen with macrolide prescribing in any trimester (adjusted risk ratio, 1.58, mainly hypospadias). The risk for any major malformation was increased with erythromycin in the first trimester (adjusted risk ratio, 1.50). There were no significant associations seen for other system-specific malformations or neurodevelopmental disorders.

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“Drug safety leaflets should report that there are concerns about the safety of macrolides, including erythromycin, and recommend the use of alternative antibiotics when feasible until further research is available,” the authors write.

Abstract/Full Text