Anna Lisa Racca
Specialist in Reproductive Medicine
Both studies confirm the safety of vaccination in young women. Interestingly, both studies look at the entire cohort of women of reproductive age. The first focuses on fertile couples, while the second focuses on infertile couples undergoing the two most commonly used techniques: ovarian stimulation and frozen embryo transfer. By looking at the entire cohort of women in the two studies we have a holistic view on safety for each woman at any level of the reproductive process (spontaneous or medicalised). Both studies are well designed, the statistical analysis is rigorous, the results are reliable and the discussion gives a clear view on possible explanations for the results recorded.
I believe that this type of evidence is strong enough to get the message across: the best option is to get vaccinated, regardless of the planned family plan.
The study in Obstetrics & Gynecology is a very large prospective cohort study. It investigates the possible association between vaccination against covid-19 and SARS-CoV-2 infection with fertility in couples trying to conceive spontaneously. It uses data from an internet-based preconception cohort study (PRESTO). Vaccination was not appreciably associated with fertility in either partner.
SARS-CoV-2 infection in the male partner was associated with a short-term decrease in fertility, which could be prevented by vaccination. Therefore, considering the known risks of SARS-CoV-2 infection during pregnancy for maternal and foetal health, and the evidence presented that there is no detrimental association with fertility, the results support vaccination against covid-19 in the preconception period.
The study in the American Journal of Epidemiology is a retrospective cohort study to determine whether there is any association between covid-19 mRNA vaccination and successful ovarian stimulation and embryo transfer. The comparison was made between fully vaccinated and unvaccinated patients who cycled during the same time period. Fertilisation rate (for ovarian stimulation) and clinical pregnancy rate (for frozen-thawed embryo transfer) were assessed first. There was no association in the adjusted analysis between covid-19 vaccination and fertilisation rate (or any of the secondary outcomes investigated), and no association between covid-19 vaccination and clinical pregnancy or any of the secondary outcomes analysed. Thus, the results of the present study contribute to the growing body of evidence regarding the safety of covid-19 vaccination in young women of reproductive age.