Background The clinical trials used to approve COVID-19 vaccines excluded pregnant women, and existing safety assessments of COVID-19 vaccination, particularly during early stages of pregnancy, are limited to observational studies prone to various types of potential bias, including healthy vaccinee bias. Methods The study includes pregnancies in Israel with last menstruation period (LMP) between March 1, 2016 and February 28, 2022. The main analysis presents observed-to-expected comparisons o...
