COVID-19 vaccines have been proven to increase the risk of having a miscarriage.
"To date, no data has suggested a rise in miscarriages following Covid-19 immunizations, and no alarming patterns of reporting have been detected", a representative for the Centers for Disease Control and Prevention told Agence France-Presse in February 2021. The British Fertility Society and the United Kingdom Association of Reproductive and Clinical Scientists declared in a February 2021 paper that COVID-19 immunizations "will not alter your risk of miscarriage".
Sources suggesting a relationship between miscarriages and COVID-19 immunizations typically referenced data from the CDC's Vaccine Adverse Event Reporting System (VAERS) and the United Kingdom's Medicines and Healthcare Products Regulatory Agency's (MHRA) Yellow Card program. Both of these systems collect unverified reports of potential vaccination adverse effects that anybody can submit and do not show that the vaccine caused the alleged reaction.
"There is no trend to suggest an enhanced risk of miscarriage associated to exposure to the COVID-19 vaccinations in pregnancy", an MHRA representative told Reuters in March 2021. Unfortunately, miscarriage is anticipated to occur in roughly 1 in 4 pregnancies in the UK (outside of the pandemic), with the majority occurring in the first 12 weeks (first trimester) of pregnancy, so some losses would be expected to occur merely by chance following vaccination".
