Reduction in stillbirth and preterm birth in COVID-19 vaccinated women

Researchers from Melbourne have just published the results of a large Melbourne-wide study analysing the rate of COVID-19 vaccine uptake among women giving birth and their pregnancy outcomes.

The study shows that there is no increase in congenital abnormalities or fetal growth restriction in women who get vaccinated during pregnancy, and that they have fewer preterm births and fewer stillbirths than unvaccinated women.

Published in the American Journal of Obstetrics and Gynaecology, the multicentre study of 32,536 births from 2021-2022 provides the first large-scale evidence on the safety of mRNA COVID-19 vaccination in an Australian pregnant population.

While the overall maternal COVID-19 vaccination coverage rose steadily following the June 2021 ATAGI recommendations for vaccination in pregnancy, the study showed a significant disparity in vaccine uptake by sociodemographic features. Overall, 85% of women giving birth at the end of March 2022 had received at least one dose of the COVID-19 vaccine.  Vaccinated women were significantly more likely to be older, having their first child, non-smoking, not requiring an interpreter, of higher socioeconomic status, and vaccinated against pertussis and influenza. Vaccination status also varied by region of birth.

Chief investigator Associate Professor Lisa Hui from the Department of Obstetrics and Gynaecology at the University of Melbourne said that with COVID numbers rising again, this is a timely reminder for women to not wait until they have had the baby to get their booster.

“We conducted this multicentre study to provide robust local evidence on mRNA COVID-19 vaccination and perinatal outcomes including stillbirth, preterm birth and congenital anomalies.” she said.

“COVID-19 vaccination during pregnancy was not associated with any adverse impacts on fetal growth or development, and was associated with benefits in terms of lower rates of stillbirth, preterm birth, and neonatal intensive care.”

“Even among the women who contracted COVID-19 infection during pregnancy, vaccination still had benefits. Vaccinated women were less likely to have a preterm birth than unvaccinated women who had COVID-19 infection during pregnancy.”

“The difference in vaccination rates by region of maternal birth really highlights the need to engage local communities in the public health messaging, and to ensure that we remove any barriers to accessing accurate health information and medical care for under-served communities.”