Despite the gap of the current and desired rate of COVID-19 vaccinations of pregnant individuals, the systematic review and meta-analysis of 10 observational studies show the vaccines are safe and effective.
COVID-19 vaccination in pregnant individuals prevents infection effectively and has no adverse outcomes, pooled analysis suggests in a recently published study. Regardless of the COVID-19 vaccine type or the trimester in which the pregnant individual received the vaccination, the study showed the lack of significant adverse pregnancy, fetal and neonatal outcomes. This study also emphasized the decrease in COVID-19 infection rate and in COVID-19-related hospitalizations in vaccinated pregnant individuals.
“There is a gap between the current rate of vaccination and the desired rate, owing to doubts regarding the safety of the available vaccines,” the investigators wrote in a recent study in American Journal of Infection Control, titled “Is it safe and effective to administer COVID-19 vaccines during pregnancy? A systematic review and meta-analysis.” They continued, “Our meta-analysis reinforced the lack of adverse outcomes in association with COVID-19 vaccination during and after pregnancy for females and neonates and reiterated the effectiveness of the former as well.”
Investigators included 10 observational studies (n = 326,499) analyzing pregnant women. Their results suggested that COVID-19 vaccination effectively prevents infection (OR: 0.56, 95% CI: 0.47, 0.67; P = < 0.00001) and related hospitalizations (OR: 0.50, 95% CI: 0.31, 0.82; P = 0.006). The vaccination does not change adverse outcomes in pregnancy, according to the results of the study, namely preeclampsia or eclampsia, stroke (4 weeks of delivery), meconium-stained amniotic fluid, spontaneous vaginal delivery, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, and blood transfusions. The COVID-19 vaccine also was observed to shield against neonatal intensive care unit (ICU) admissions from COVID-19 (OR: 0.85; 95% CI: 0.81, 0.90; P = < 0.00001).
The investigators note that their study showed “no adverse pregnancy outcomes in vaccinated females in comparison to the unvaccinated. Current guidelines being followed regarding vaccination of pregnant females enforce the administration of the inactivated influenza vaccine and the inactivated tetanus, diphtheria, pertussis vaccine, with live vaccines such as the measles, mumps, rubella vaccine and the varicella vaccine being contraindicated in pregnancy,” the investigators wrote. “The type of vaccine plays a major role in its respective safety profile, with live vaccines being contraindicated due to the increased risk of perinatal infection and congenital birth defects—while inactivated vaccines do not pose such risks to the mother or fetus.”
In the study, among fetal outcomes, preterm birth numbers decreased after vaccination in Israel (OR: 0.87; 95% CI: 0.76, 0.99; P = 0.03) and Norway (OR: 0.81; 95% CI: 0.71, 0.92; P = 0.001), in comparison to United States and Sweden which showed no difference. The incidence of stillbirth decreased in Norway (OR: 0.42; 95% CI: 0.20, 0.91; P = 0.03) and Sweden (OR: 0.71; 95% CI: 0.52, 0.99; P = 0.04) with no change in the groups from the other locations.
“The Royal College of Obstetricians and Gynaecologists have suggested that pregnant women should preferably take their COVID-19 vaccine after the first trimester, provided they are not at an increased risk for infection with the virus due to the fetus being more susceptible to the development of adverse outcomes during that window,” the investigators said in the study. “Nevertheless, several studies including ours have not shown a significant change in neonatal adverse outcomes, post-vaccination in the first trimester.”
However, the investigators acknowledge large-scale trials in a randomized fashion are needed in the future to confirm results of this study.
Additionally, “Clear guidelines are needed to help health care professionals in advising and implementing the vaccination of pregnant females against COVID-19. Pregnant patients also require the assurance needed to readily take the vaccine. Our meta-analysis can act as a reference for health care professionals and policymakers, for the prompt and much-needed vaccination of pregnant females against the SARS-CoV-2 virus,” the investigators noted.