Systematic review and meta-analysis of the effectiveness and perinatal outcomes of COVID-19 vaccination in pregnancy

• Published in: Nature communications 2022-05, Vol.13 (1), p.2414-8, Article 2414
• Main Authors: Prasad, Smriti, Kalafat, Erkan, Blakeway, Helena, Townsend, Rosemary, O’Brien, Pat, Morris, Edward, Draycott, Tim, Thangaratinam, Shakila, Le Doare, Kirsty, Ladhani, Shamez, von Dadelszen, Peter, Magee, Laura A., Heath, Paul, Khalil, Asma
• Format: Article
• Language: English
• Subjects: 631/326/590; 631/326/596/4130; 692/699/255/2514; 692/700/478/174; Birth weight; Coronaviruses; COVID-19 - prevention & control; COVID-19 vaccines; COVID-19 Vaccines - adverse effects; Embolism; Female; Hemorrhage; Humanities and Social Sciences; Humans; Immunization; Infant, Newborn; Intensive care; Intensive Care Units, Neonatal; Meta-analysis; mRNA; multidisciplinary; Neonates; Placenta; Pregnancy; Premature Birth - epidemiology; RNA, Messenger; SARS-CoV-2; Science; Science (multidisciplinary); Severe acute respiratory syndrome coronavirus 2; Stillbirth; Stillbirth - epidemiology; Systematic review; Vaccination; Vaccines
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-30052-w

Safety and effectiveness of COVID-19 vaccines during pregnancy is a particular concern affecting vaccination uptake by this vulnerable group. Here we evaluated evidence from 23 studies including 117,552 COVID-19 vaccinated pregnant people, almost exclusively with mRNA vaccines. We show that the effectiveness of mRNA vaccination against RT-PCR confirmed SARS-CoV-2 infection 7 days after second dose was 89·5% (95% CI 69·0-96·4%, 18,828 vaccinated pregnant people, I 2  = 73·9%). The risk of stillbirth was significantly lower in the vaccinated cohort by 15% (pooled OR 0·85; 95% CI 0·73–0·99, 66,067 vaccinated vs. 424,624 unvaccinated, I 2  = 93·9%). There was no evidence of a higher risk of adverse outcomes including miscarriage, earlier gestation at birth, placental abruption, pulmonary embolism, postpartum haemorrhage, maternal death, intensive care unit admission, lower birthweight Z-score, or neonatal intensive care unit admission ( p  > 0.05 for all). COVID-19 mRNA vaccination in pregnancy appears to be safe and is associated with a reduction in stillbirth. Pregnant women have been disproportionately under-vaccinated against COVID-19, partly because they were excluded from initial trials. This systematic review and meta-analysis supports efficacy of vaccination in pregnancy, and finds no evidence of adverse maternal or perinatal outcomes.