Dr. Howard Smith Oncall

  Vidcast:  https://youtu.be/WH-Mgs6TIWo Macrolide antibiotics like erythromycin, Zithromax, and clarithromycin, if taken during the first trimester, can trigger major cardiovascular malformations in a baby.  A just published British study reviewed a national database of 100,000 children.   Those women who took one course of macrolide antibiotic during their first 3 months of pregnancy were 1.5 times more likely to have fetal heart malformations and 1.6 times more likely to have genital problems when compared to those prescribed penicillin antibiotics.  Although macrolides produced  no increased risk for heart problems later in pregnancy, risk of genital malformations remained.   If you’re pregnant, avoid all medications during the first trimester but these macrolide antibiotics until after you deliver.    Fan Heng, Gilbert Ruth, O’Callaghan Finbar, Li Leah. Associations between macrolide antibiotics prescribing during pregnancy and adverse child outcomes in the UK: population based cohort study BMJ 2020; 368