Background
Early in the COVID-19 pandemic, there was no evidence that COVID-19 posed greater risk to pregnant people. Over the subsequent year, it became clear that pregnancy rendered more at higher risk of severe COVID-19. There is, however, a paucity of data regarding COVID-19 perinatal outcomes in low-middle income countries (LMIC). The aim of this study was to evaluate the effect of SARS-CoV-2 infection on adverse maternal and perinatal outcomes in a reference maternity hospital, in a low income setting in Rio de Janeiro during the COVID-19 pandemic.
Methods
The study was conducted a prospective cohort study of 1,185 pregnant people ≥ 16 years admitted to a maternity hospital and their infants from March 2020 to March 2022. Participants with laboratory confirmed SARS CoV-2 infection were considered infected. An exploratory analysis of qualitative variables was conducted with absolute and relative frequencies and 95% confidence intervals calculated. Survival functions were estimated by the Kaplan-Meier method, and the Cox proportional hazards model was employed to interpret the effects of SARS-CoV-2 infection on time to adverse maternal and perinatal outcomes, adjusted for vaccination, comorbidity and gestational trimester.
Results
A total of 21% (249/1185) patients were infected with SARS-CoV-2, with a median age of 26 (range: 16–47). Cesarean section deliveries were performed in 54% (135/249) SARS CoV-2 + participants vs 41.7% (391/936) of uninfected, p = < 0.001. SARS CoV-2 vertical transmission was observed in 6 of 169 (3.6%) tested neonates. Preterm deliveries occurred more frequently in patients testing positive for SARS-CoV-2 (30.7% vs 23.6). In the survival analysis, no effect of SARS-CoV-2 infection was observed on prematurity (HR: 0.85, 95% CI: 0.66–1.11) and adverse perinatal outcomes including fetal distress (HR: 0.94, 95% CI: 0.59–1.49); stillbirth (HR: 0.84, 95% IC: 0.42–1.71) and neonatal death (HR: 0.91, 95% CI: 0.39–2.14), even after adjusting for vaccination, comorbidity and gestational trimester of infection. Intensive care unit admission and/or death occurred in 68 of 1185 participants (5.7%); 44 of 249 participants (17.7%) infected with SARS CoV-2 vs. 24 of 936 uninfected participants (2.5%). Patients infected with SARS-CoV-2 were at greater risk of adverse maternal outcomes (crude HR: 6.12, 95% CI: 3.70-10.14; adjusted HR: 5.60, 95% CI: 3.35–9.37) than uninfected pregnant participants. All 21 participants who died were unvaccinated against COVID-19.
Conclusion
The risk of maternal death due to COVID-19 highlights the need for adequate preventive measures, particularly vaccination, during the prenatal and postpartum periods.
