According to the recommendations from the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA), pregnant women should be vaccinated against COVID-19. However, the main research work to back up this policy was the influential CDC-sponsored article by Shimabukuro et al. (2021), published in the New England Journal of Medicine, which has been corrected after wide criticism. In the published correction, the authors stated that “No denominator was available to calculate a risk estimate for spontaneous abortions because, at the time of this report, follow-up through 20 weeks was not yet available for 905 of the 1224 participants vaccinated within 30 days before the first day of the last menstrual period or in the first trimester. Furthermore, any risk estimate would need to account for the gestational week–specific risk of spontaneous abortion.”
Therefore, there is essentially little assurance of the COVID-19 vaccine safety on women during pregnancy, particularly for those exposed in early pregnancy in their first trimester. But the article’s abstract and conclusions did not reflect the correction regarding the risks in the first trimester, and neither did CDC change its policy accordingly.
