COVID- 19 antibody positivity over time and pregnancy outcomes in seven low- and- middle- income countries: A prospective, observational study of the Global Network for Women's and Children's Health Research

Abstract

Objectives: To determine COVID- 19 antibody positivity rates over time and rela tionships to pregnancy outcomes in low- and middle- income countries (LMICs). Design: With COVID- 19 antibody positivity at delivery as the exposure, we per formed a prospective, observational cohort study in seven LMICs during the early COVID-19 pandemic. Setting: The study was conducted among women in the Global Network for Women's and Children's Health's Maternal and Newborn Health Registry (MNHR), a pro spective, population- based study in Kenya, Zambia, the Democratic Republic of the Congo (DRC), Bangladesh, Pakistan, India (two sites), and Guatemala. Population: Pregnant women enrolled in an ongoing pregnancy registry at study sites. Methods: From October 2020 to October 2021, standardised COVID- 19 antibody testing was performed at delivery among women enrolled in MNHR. Trained staff masked to COVID- 19 status obtained pregnancy outcomes, which were then com pared with COVID- 19 antibody results. Main Outcome Measures: Antibody status, stillbirth, neonatal mortality, maternal mortality and morbidity. Results: At delivery, 26.0% of women were COVID- 19 antibody positive. Positivity increased over the four time periods across all sites: 13.8%, 15.4%, 21.0% and 40.9%. In the final period, positivity rates were: DRC 27.0%, Kenya 33.1%, Pakistan 32.8%, Guatemala 37.0%, Zambia 37.8%, Bangladesh 47.2%, Nagpur, India 57.4% and Belagavi, India 62.4%. Adjusting for site and maternal characteristics, stillbirth, neonatal mortal ity, low birthweight and preterm birth were not significantly associated with COVID- 19. The adjusted relative risk (aRR) for stillbirth was 1.27 (95% CI 0.95– 1.69). Postpartum haemorrhage was associated with antibody positivity (aRR 1.44; 95% CI 1.01– 2.07). Conclusions: In pregnant populations in LMICs, COVID- 19 antibody positivity has increased. However, most adverse pregnancy outcomes were not significantly associ ated with antibody positivity.