COVID-19 Evidence Alerts
from McMaster PLUS^TM

BACKGROUND: There are limited data regarding COVID-19 vaccination during pregnancy.

OBJECTIVES: To evaluate the effects of COVID-19 vaccination received during pregnancy on SARS-CoV-2 infection, COVID-19-related hospitalisation, COVID-19-related intensive care unit (ICU) admission and maternal-fetal complications.

SEARCH STRATEGY: MEDLINE, CINHAL, Embase, Scopus and CENTRAL databases, as well as ClinicalTrials.gov, reference lists, related articles and grey literature sources.

SELECTION CRITERIA: Randomised controlled trials, non-randomised studies of interventions, pregnant women, COVID-19 vaccination during pregnancy.

DATA COLLECTION AND ANALYSIS: Study selection, risk-of-bias assessment, data extraction and assessment of the certainty of evidence using the GRADE method were performed independently by two authors. Meta-analyses were performed using Cochrane RevMan 5.4. PROSPERO registration number: CRD42022308849.

MAIN RESULTS: We included 14 observational studies (362 353 women). The administration of a COVID-19 vaccine during pregnancy resulted in a statistically significant reduction in SARS-CoV-2 infection (OR 0.46, 95% CI 0.28-0.76) and COVID-19-related hospitalisation (OR 0.41, 95% CI 0.33-0.51). The effect appeared to be greater in fully vaccinated women, for both infection (OR 0.31, 95% CI 0.16-0.59) and hospitalisation (OR 0.15, 95% CI 0.10-0.21). However, the certainty of evidence was very low. The difference in COVID-19-related ICU admission between vaccinated and unvaccinated individuals did not reach statistical significance (OR 0.58, 95% CI 0.13-2.58). Finally, there were no statistically significant differences in any of the maternal-fetal complications considered in the included studies.

CONCLUSIONS: COVID-19 vaccination administered during pregnancy seems to reduce SARS-CoV-2 infection and COVID-19-related hospitalisation, with no significant effects on maternal-fetal complications.