COVID‐19 Antibody Positivity at Delivery in Low‐ and Middle‐Income Countries: A Prospective, Observational Study of the Global Network With Results Through July 2022

Abstract

ABSTRACT Objectives Limited population‐based data have evaluated COVID‐19 infections during pregnancy in low‐ and middle‐income countries (LMICs). We updated COVID‐19 antibody positivity rates and relationships to pregnancy outcomes in unvaccinated women in LMICs. Design COVID‐19 antibody testing was conducted for pregnant women at delivery. We evaluated pregnancy outcomes using data collected in a prospective registry. Setting The Maternal and Newborn Health Registry (MNHR) is a prospective, population‐based study in specific geographic communities in Kenya, Zambia, the Democratic Republic of the Congo (DRC), Bangladesh, Pakistan, India, and Guatemala. Methods From October 2020 to October 2021, we conducted COVID‐19 antibody testing at delivery among women enrolled in the MNHR ( n = 14 015). Results include women delivering from November 2021 to July 2022 ( n = 8204). Outcomes among women who were COVID‐19 positive versus negative at delivery were compared among women unvaccinated for COVID‐19. Outcome Measures COVID‐19 antibody positivity rates, stillbirth, neonatal mortality, maternal mortality, and morbidity. Results Vaccination among pregnant women increased from < 1% (October 2020–October 2021) to 30.4% (November 2021–June 2022). In the final period, COVID‐19 vaccination rates ranged from 0.1% in DRC to 67.4% in Guatemala. Among unvaccinated women, the antibody positivity rate overall was 14.0% (October 2020–December 2020), increasing to 69.5% during May–July 2022. Over time, antibody positivity rates increased until January 2022 for women in all sites, when the positivity rates remained relatively stable through July 2022. In the final period, antibody positivity rates ranged from 59.4% (DRC) to 88.0% (India). After adjusting for site and maternal characteristics, antibody positivity was not associated with any adverse fetal/neonatal outcome. Conclusions In the pregnant populations across seven LMICs, COVID‐19 infections occurred in over 50% of unvaccinated women overall. Adverse pregnancy outcomes, including preterm birth, low birthweight, stillbirth, neonatal death, and antepartum hemorrhage, were not increased in women who were antibody positive compared to women who were antibody negative in either time period.