Conclusion
Our investigation of five CA signals related to macrolides found negative results. While a positive association was not found between CHD as a group and macrolides, an elevated risk was found between macrolides and specific macrolides (erythromycin, clarithromycin and azithromycin) and AVSD. We also found elevated risk for other defects associated with first trimester use of specific macrolides that need further follow up in independent datasets. Guidelines on the teratogenic risk of macrolide use during the first trimester of pregnancy should take the current findings into account. These results should also guide recommendations for pregnant women when azithromycin is considered as part of COVID-19 treatment.