There have been two substantial studies published recently regarding miscarriage and vaccination – one in JAMA in September 2021 and one in the the New England Journal of Medicine in October 2021.
In the JAMA study, they used a case-control surveillance model from the Vaccine Safety Datalink in collaboration with CDC in US women. They evaluated the odds of miscarriage after receiving a Covid vaccine (within 28 days). There was no increased odds of having a miscarriage after receiving the Covid vaccination in this sample of over 100,000 pregnancies analyzed.
In the NEJM study, including researchers from Ottawa, the US and Norway, they also used a case-control model looking at Norwegian women (a sample of over 18,000 pregnancies analyzed). In this study, the odds of miscarriage was also not increased in those having received a Covid vaccination in the past 3 to 5 weeks.
Given the large sample sizes of these studies, their case-control design and population-based approach, this can provide ample reassurance to those worried about miscarriage risk related to the Covid vaccine.