COVID-19 vaccination associated with lower rates of adverse pregnancy outcomes

Pregnant women who vaccinated against COVID-19 had lower rates of perinatal death, preterm delivery, neonates with very low birth weight and NICU admission than unvaccinated women, researchers reported in Obstetrics & Gynecology.

“Despite strong recommendations and clear maternal benefit for vaccinated pregnant patients, vaccine uptake among pregnant patients lags behind other high-risk groups with persistent regional variations,” John A. Morgan, MD, fellow in the department of maternal-fetal medicine at the Ochsner Clinic Foundation and the Ochsner Clinical School, New Orleans, and colleagues wrote. “Hesitancy surrounding the COVID-19 vaccine in pregnancy is centered around preexisting vaccine hesitancy in the pregnant population, the spread of misinformation regarding the risks of the COVID-19 vaccine to pregnant and lactating individuals, the lack of data regarding safety due to exclusion of pregnant and lactating individuals from initial vaccine trials and the perception that individual risk is low in young healthy reproductive-aged females.”

This large retrospective cohort study included 15,865 pregnant women who delivered 16,132 newborn infants after 20 weeks’ gestation within a large U.S. regional health system in 2021. A total of 2,069 women received two doses of the messenger RNA (mRNA) COVID-19 vaccine from Pfizer-BioNTech or Moderna and were categorized into the vaccinated group; 13,796 women did not get the vaccine and were in the unvaccinated group.

The primary outcome was perinatal death, such as stillbirth and neonatal death.

Despite only 13% of study participants being included in the vaccination group, the vaccination rate increased during the study period as the vaccine became more widely available and accepted. Those who received the vaccine were older, more likely to be of non-Black racial or non-Hispanic ethnic backgrounds, had private insurance and higher BMIs.

Researchers observed a lower incidence of perinatal death (0.5% vs. 0.8%; aOR = 0.2; 95% CI, 0.05-0.88) among women who were vaccinated compared with unvaccinated. Vaccination was also associated with lower rates of preterm delivery (aOR = 0.63; 95% CI, 0.48-0.82), neonates born with very low birth weight (aOR = 0.35; 95% CI, 0.15-0.84) and NICU admission (aOR = 0.66; 95% CI, 0.52-0.85).

In addition, researchers noted that the association between vaccination and lower rate of perinatal death was not significant after propensity score matching.

“Our findings support the continued strong recommendation by the CDC, the American College of Obstetricians and Gynecologists and the Society of Maternal-Fetal Medicine for vaccination of all pregnancy patients against COVID-19,” the researchers wrote.