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Meta-Analysis
. 2022 May 10;13(1):2414.
doi: 10.1038/s41467-022-30052-w.

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

Smriti Prasad #  1 , Erkan Kalafat #  2   3 , Helena Blakeway  1 , Rosemary Townsend  4   5 , Pat O'Brien  6   7 , Edward Morris  6   8 , Tim Draycott  6   9 , Shakila Thangaratinam  10 , Kirsty Le Doare  11 , Shamez Ladhani  12   13 , Peter von Dadelszen  14 , Laura A Magee  14 , Paul Heath  11 , Asma Khalil  15   16
Affiliations
Meta-Analysis

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

Smriti Prasad et al. Nat Commun. .

Abstract

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, I2 = 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, I2 = 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.

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Conflict of interest statement

P.O.B. is co-chair of the Royal College of Obstetricians and Gynaecologists (RCOG) Vaccine Committee. P.O.B. and T.D. are RCOG Vice-Presidents. E.M. is RCOG President. P.H. is a member of the RCOG Vaccine Committee. P.H. is CI of the Preg-Cov trial (UK multicentre COVID vaccination in pregnancy). A.K. is obstetric PI of the Preg-Cov trial (UK multicentre COVID vaccination in pregnancy). A.K. is a member of the COVAX Working Group on COVID vaccination in pregnancy. A.K. is PI of the Pfizer COVID vaccination in pregnancy trial. The remaining authors declare no competing interests.

Figures

Fig. 1
Fig. 1. PRISMA flow diagram.
Flow diagram summarises the number of studies excluded at each stage.
Fig. 2
Fig. 2. Forest plot of studies reporting vaccine effectiveness.
Vertical ticks within the red boxes and horizontal lines show the mean effect and 95% confidences interval for each study. Black diamond at the bottom shows the cumulative effect with 95% confidence intervals.
Fig. 3
Fig. 3. Forest plot of studies reporting stillbirth rate.
Vertical ticks within the blue boxes and horizontal lines show the mean effect and 95% confidences interval for each study. Black diamond at the bottom shows the cumulative effect with 95% confidence intervals.
Fig. 4
Fig. 4. Forest plot of studies reporting hypoxic brain injury.
Vertical ticks within the blue boxes and horizontal lines show the mean effect and 95% confidences interval for each study. Black diamond at the bottom shows the cumulative effect with 95% confidence intervals.
Fig. 5
Fig. 5. Forest plot of studies reporting on preterm birth rate prior to 37 weeks' (a), 34 weeks' (b) and 32 weeks' (c) gestation.
Vertical ticks within the blue boxes and horizontal lines show the mean effect and 95% confidences interval for each study. Black diamond at the bottom shows the cumulative effect with 95% confidence intervals.
Fig. 6
Fig. 6. Forest plot of studies reporting miscarriage rate and accounting for time-varying confounding.
Vertical ticks within the red boxes and horizontal lines show the mean effect and 95% confidences interval for each study. Black diamond at the bottom shows the cumulative effect with 95% confidence intervals.
See this image and copyright information in PMC

References

    1. Polack FP, et al. Safety and efficacy of the BNT162b2 mRNA covid-19 vaccine. N. Engl. J. Med. 2020;383:2603–2615. doi: 10.1056/NEJMoa2034577. - DOI - PMC - PubMed
    1. Voysey M, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2021;397:99–111. doi: 10.1016/S0140-6736(20)32661-1. - DOI - PMC - PubMed
    1. Viana J, et al. Controlling the pandemic during the SARS-CoV-2 vaccination rollout. Nat. Commun. 2021;12:3674. doi: 10.1038/s41467-021-23938-8. - DOI - PMC - PubMed
    1. ACOG. COVID-19 Vaccination Considerations for Obstetric–gynecologic Care, December 2020 (ACOG, accessed 25 August 2021); https://www.acog.org/clinical/clinical-guidance/practice-advisory/articl....
    1. PHE. JCVI Issues New Advice on COVID-19 Vaccination for Pregnant Women, 2021 [PHE, accessed 25 August 2021); https://www.gov.uk/government/news/jcvi-issues-new-advice-on-covid-19-va....