COVID-19 reinfection in pregnancy: Assessment of severity and pregnancy outcomes in England

Background: Disease severity and pregnancy outcomes following SARS-CoV-2 reinfections in pregnancy are not well understood. Methods: We linked women aged 18 to 50 years testing positive in the community for COVID-19 between April 2021 and March 2022 to hospital, vaccine and maternal services databases. We compared hospital and intensive care unit (ICU) admission rates following infection and reinfection in pregnant and non-pregnant women, and low birthweight, prematurity and stillbirth in women infected and reinfected during pregnancy. Results: We identified 68,842 pregnant and 3,915,069 infected non-pregnant women. Hospital admission after SARS-CoV-2 reinfection was more common in pregnancy, especially during the third trimester (aOR= 18.56; 95% CI: 9.46 - 36.42) and was similar following reinfection or primary infection in pregnancy (aOR= 0.82; 95% CI: 0.50 - 1.33). All ICU admissions (n=49) in pregnancy occurred after primary infection with delta. There was no notable difference in adverse pregnancy outcomes after primary infection or reinfection with SARS-CoV-2 during pregnancy. Conclusion: Pregnant women remain at higher risk of more severe disease during reinfection compared to non-pregnant women yet; hospitalisation and ICU admissions risk were low during the omicron period. The virulence of circulating variants needs to be assessed to guide maternal COVID-19 vaccination programmes against.