ABSTRACT
Objectives: To identify factors associated with adverse maternal outcomes during the COVID-19 pandemic. Methods: Single-center prospective cohort study at a maternity department in a public general hospital in Rio de Janeiro. All pregnant women evaluated for emergency care, for labor and delivery, for respiratory symptoms, for obstetrical or medical reasons between May 2020 to March 2022 at the participating institution were offered enrollment. The endpoint was maternal mortality or ICU admission. Results: 1609 pregnant women were enrolled; 25.5% participants (n=410) were infected with SARS-CoV-2 based on RT-PCR or an antigen test. There were 21 deaths and 67 ICU admissions in 4% of the cohort. Severe maternal morbidity and mortality incidence was higher during the Gamma than Delta waves (p =0.003). Vaccination conferred protection against the endpoint (RR: 0.4, 95% CI:0.1-0.9, p=0.0169). Factors associated with severe morbidity and mortality included Cesarean section (RR: 3.7, 95% CI: 1.7-7.9, p=0.0008), SARS-CoV-2 infection in the third trimester (RR: 2.4, 95% CI: 1.1-5.6, p=0.0006) and comorbidities (RR: 3, 95% CI= 1.8-5.2, p< 0.0001). Conclusions: : COVID-19 was significantly associated with the risk of severe maternal morbidity and mortality. Immunization of pregnant women against COVID-19 was highly protective against adverse outcomes and should be encouraged during pregnancy.