Associations between macrolide antibiotics prescribing during pregnancy and adverse child outcomes in the UK: population based cohort study

Study (n=104,605) found macrolide prescribing during 1st trimester was linked to increased risk of any major malformation vs. penicillin (27.65 v 17.65 per 1000, adjusted risk ratio 1.55, 95% CI 1.19-2.03) and specifically CV malformations (10.60 v 6.61 per 1000, 1.62, 1.05-2.51)

British Medical Journal