SARS-CoV-2 infection and COVID-19 vaccination rates in pregnant women in Scotland

Abstract

Population-level data on COVID-19 vaccine uptake in pregnancy and SARS-CoV-2 infection outcomes are lacking. We describe COVID-19 vaccine uptake and SARS-CoV-2 infection in pregnant women in Scotland, using whole-population data from a national, prospective cohort. Between the start of a COVID-19 vaccine program in Scotland, on 8 December 2020 and 31 October 2021, 25,917 COVID-19 vaccinations were given to 18,457 pregnant women. Vaccine coverage was substantially lower in pregnant women than in the general female population of 18-44 years; 32.3% of women giving birth in October 2021 had two doses of vaccine compared to 77.4% in all women. The extended perinatal mortality rate for women who gave birth within 28 d of a COVID-19 diagnosis was 22.6 per 1,000 births (95% CI 12.9-38.5; pandemic background rate 5.6 per 1,000 births; 452 out of 80,456; 95% CI 5.1-6.2). Overall, 77.4% (3,833 out of 4,950; 95% CI 76.2-78.6) of SARS-CoV-2 infections, 90.9% (748 out of 823; 95% CI 88.7-92.7) of SARS-CoV-2 associated with hospital admission and 98% (102 out of 104; 95% CI 92.5-99.7) of SARS-CoV-2 associated with critical care admission, as well as all baby deaths, occurred in pregnant women who were unvaccinated at the time of COVID-19 diagnosis. Addressing low vaccine uptake rates in pregnant women is imperative to protect the health of women and babies in the ongoing pandemic.

Fig. 1. Populations invited for COVID-19 vaccination in Scotland over time.

Summary of population cohorts invited for COVID-19 vaccination over time in Scotland from the start of the vaccination program on 8 December 2020 (left) and policy changes relevant to vaccination in pregnant women (right).

Fig. 2. Summary of participants in the COVID-19 in Pregnancy in Scotland cohort.

Flow chart summarizing participants in the COPS cohort. Counts for molar pregnancies, ectopic pregnancies, miscarriages, terminations and deliveries are numbers of pregnancies. Live births, stillbirths and neonatal deaths are numbers of babies.

Fig. 3. COVID-19 vaccination uptake and coverage.

a, Monthly uptake of COVID-19 vaccination in all women 18−44 years and in pregnant women. b, Monthly uptake of COVID-19 vaccination in pregnant women by age group. c, Monthly uptake of COVID-19 vaccination in pregnant women by SIMD quintile. SIMD, Scottish Index Multiple Deprivation, with SIMD 5 being least deprived and 1 being most deprived. d, Vaccine coverage in the general female population in women age 18−44 years (purple) and percentage of pregnant women vaccinated before the time of birth (green). Numbers of women 18−44 years were derived from 2020 mid-year population estimates.

Fig. 4. SARS-CoV-2 in pregnancy and outcomes by vaccination status.

a, SARS-CoV-2 in all women 18−44 years per 100,000 women and in pregnant women. b, Monthly rates of SARS-CoV-2 per 100,000 pregnant women by age group c, Monthly rates of SARS-CoV-2 per 100,000 pregnant women by SIMD. d, Percentage of cases of SARS-CoV-2 infection in pregnancy occurring 1 December 2020 to 31 October 2021 inclusive, cases with associated hospital admission and cases with associated critical care admission, by vaccination status at the date of onset of COVID-19. Unvaccinated is defined as no COVID-19 vaccination before the date of onset of COVID-19 or one dose of vaccination ≤21 d previously in line with standard definitions used by Public Health Scotland.

Fig. 5. Preterm birth and perinatal mortality after SARS-CoV-2 in pregnancy.

a,b, Preterm birth (<37 weeks gestation) rate per 100 live births (a) and extended perinatal mortality rates (b) (stillbirths (death in utero ≥24 weeks gestation) and neonatal deaths within 28 d of birth per 1,000 total births) in different cohorts during the pandemic. Background rate is the rate for all babies born during the pandemic period (1 March 2020 to 31 October 2021); no confirmed SARS-CoV-2 is the rate for babies born during the pandemic period (1 March 2020 to 31 October 2021) to women with no confirmed SARS-CoV-2 infection during pregnancy; any SARS-CoV-2 is the rate for babies born to women who had confirmed SARS-CoV-2 during their pregnancy 1 December 2020 to 31 October 2021; SARS-CoV-2 within 28 d of birth is the rate for babies born to women who had confirmed SARS-CoV-2 during their pregnancy 1 December 2020 to 31 October 2021, restricted to babies born within 28 d of the date of onset of maternal infection; Any COVID-19 vaccination is the rate for babies born to women who had COVID-19 vaccination during their pregnancy 1 December 2020 to 31 October 2021; COVID-19 vaccination within 28 d of birth is the rate for babies born to women who had COVID-19 vaccination during their pregnancy 1 December 2020 to 31 October 2021, restricted to babies born within 28 d of the date of maternal vaccination.

Fig. 6. Hospital and critical care admissions after SARS-CoV-2 and COVID-19 vaccination in pregnancy.

a, Percentage of cases of SARS-CoV-2 infections in pregnancy associated with hospital admission (defined as hospital admission ≤14 d after the date of diagnosis of SARS-2-CoV infection or if the date of diagnosis occurred at any point during a hospital admission) and COVID-19 vaccinations in pregnancy associated with hospital admission (defined as hospital admission ≤14 d after the date of COVID-19 vaccination) occurring 1 December 2020 to 30 September 2021. b, Percentage of SARS-CoV-2 infections in pregnancy associated with critical care admission (defined as critical care admission ≤21 d after the date of diagnosis of SARS-CoV-2 infection or if the date of diagnosis occurred at any point during a critical care admission) and COVID-19 vaccinations in pregnancy associated with critical care admission (defined hospital admission ≤21 d after the date of COVID-19 vaccination) occurring 1 December 2020 to 30 September 2021. Definitions are as per Public Health Scotland standards for associated hospital admission and critical care admission. Data are restricted to infections and vaccinations occurring up to 30 September 2021 due to incomplete follow-up times.