Meta-Analysis Shows Safety of COVID-19 Vaccination During Pregnancy

Adverse maternal, fetal, and neonatal outcomes did not significantly differ between women who did and did not receive COVID-19 vaccination during pregnancy.

COVID-19 vaccination during pregnancy effectively reduces the risk for maternal and neonatal COVID-19 infection and does not increase the occurrence of adverse maternal, fetal, or neonatal outcomes compared with no vaccination, according to study findings published in the American Journal of Infection Control.

Researchers conducted a systematic review and meta-analysis of studies published through March 2022 related to the safety and efficacy of COVID-19 vaccination during pregnancy. They identified 10 eligible observational studies for inclusion, comprising data from women who were pregnant. A random-effects model was used to assess pooled results, including potential heterogeneity. The primary outcome was the safety of COVID-19 vaccination during pregnancy.

The overall study population included a total of 326,499 patients, of whom 79,460 were vaccinated and 247,039 were unvaccinated against COVID-19 infection during pregnancy.

Analysis of unvaccinated and vaccinated patients showed no difference in the occurrence of preeclampsia (odds ratio [OR], 1.07; 95% CI, 0.78-1.45; P =.68), stroke within 4 weeks prior to or after delivery (OR, 1.13; 95% CI, 059-2.17; P =.71), spontaneous abortion (OR, 1.54; 95% CI, 0.41-5.76; P =.52), or need for blood transfusion (OR, 1.37; 95% CI, 0.90-2.10; P =.15).

Our study clearly outlined the lack of significant adverse pregnancy, fetal and neonatal outcomes after COVID-19 vaccine.

Delivery-related outcomes, such as meconium-stained amniotic fluid (OR, 0.70; 95% CI, 0.42-1.16; P =.17), spontaneous vaginal delivery (OR, 0.90; 95% CI, 0.69-1.17; P =.43), operative vaginal delivery (OR, 0.99; 95% CI, 0.59-1.67; P =.97), cesarean delivery (OR: 1.10; 95% CI, 0.95-1.27; P =.21), and postpartum hemorrhage (OR, 0.88; 95% CI, 0.77-1.01; P =.07) also did not significantly differ between vaccinated and unvaccinated patients.

Compared with unvaccinated patients, no significant differences were noted among vaccinated patients in regard to the occurrence of adverse fetal or neonatal outcomes, including stillbirth (OR, 1.02; 95% CI, 0.82-1.26; P =.87), preterm birth prior to 37 weeks (OR, 1.00; 95% CI, 0.95-1.06; P =.87), Apgar scores lower than 7 (OR, 0.94; 95% CI, 0.86-1.04; P =.22), small for gestational age (OR, 0.99; 95% CI, 0.92-1.06; P =.67), or low (<2500 g) birth weight (OR, 0.99; 95% CI, 0.69-1.42; P =.96). Of note, the occurrence of very low (<1500 g) birth weight (OR, 0.79; 95% CI, 0.18-3.54; P =.76; I2 =82%) was the only outcome with significant heterogeneity between vaccinated and unvaccinated patients.

Receipt of maternal COVID-19 vaccination was found to be associated with significantly reduced rates of neonatal intensive care unit admission (OR, 0.85; 95% CI, 0.81-0.90; P <.00001).

Study limitations include the lack of randomized controlled trials, different standards for what was considered full vaccination, and potential confounding bias.

“Our study clearly outlined the lack of significant adverse pregnancy, fetal and neonatal outcomes after COVID-19 vaccine,” the researchers concluded.


Hameed I, Khan MO, Nusrat K, et al. Is it safe and effective to administer COVID-19 vaccines during pregnancy? a systematic review and meta-analysis. Am J Infect Control. Published online August 22, 2022. doi:10.1016/j.ajic.2022.08.014