COVID vaccines do not increase the risk of pregnancy loss

Much has been said since the beginning of the COVID vaccination about safety and the need to vaccinate pregnant women. From the beginning of the pandemic, it was established that pregnant women were part of the risk groups in case of contracting coronavirus. However, safety data on vaccination during pregnancy remain limited, and it is also not clear whether inoculation by the mother is sufficient for the mother to pass antibodies to the baby on the way. And that is what leads many women to doubt the possibility of being immunized.

Now researchers from the University of Ottawaanalyzed various Norwegian national health registries to compare the proportion of vaccinated women who experienced a miscarriage during the first trimester and of women who were still pregnant at the end of the first trimester. And they found no correlation between COVID-19 vaccines and the risk of miscarriage in the first trimester, providing further evidence for the safety of the COVID-19 vaccine during pregnancy.

“Our study found no evidence of an increased risk of miscarriage after COVID-19 vaccination, so this adds to the conclusions of other reports that support COVID-19 vaccination during pregnancy,” stated the study authors, from the School of Epidemiology and Public Health at the University of Ottawa School of Medicine and the Eastern Ontario Children’s Hospital Research Institute.

The study’s findings, which were published in The New England Journal of Medicine, “They are reassuring for women who were vaccinated early in pregnancy and support growing evidence that the COVID-19 vaccine during pregnancy is safe.”, according to the researchers.

Dr. Fell, who is currently leading an Ontario study on the effectiveness and safety of COVID-19 vaccines, and the international team behind the study found no relationship between the type of vaccine received and miscarriage. In Norway, the vaccines used included Pfizer, Moderna, and AstraZeneca.

“It is important for pregnant women to get vaccinated as they are at higher risk of hospitalizations and complications from COVID-19, and their babies are at higher risk of being born too early. Additionally, vaccination during pregnancy is likely to protect the newborn against COVID-19 infection in the first months after birth, ”the study authors wrote.

Recognizing that “a limitation of the report is that the registry lacks information on gestational age at the time of early pregnancy registration and, therefore, case-control patients could not be matched according to gestational age,” the researchers noted: “However, Most recognized miscarriages are known to occur between 6 and 10 weeks of pregnancy, a period similar to the gestational ages when women in Norway consult a doctor to confirm pregnancy. Furthermore, only about 40% of women in Norway have a primary care appointment to confirm pregnancy, but the characteristics of these women appear to be similar to those of women who do not have a registered pregnancy confirmation”.

“We cannot address associations between vaccination and miscarriages that were not clinically recognized. Although adjustment for possible confounding factors had a minimal effect on our results, the registry does not include information on lifestyle and other factors that could confound our findings,” they added.