Factors associated with vaccination against Covid-19 in pregnant and hospitalized postpartum women: A retrospective cohort study

Objective To analyze the characteristics associated with vaccination against Covid-19 in pregnant and postpartum women with Severe Acute Respiratory Syndrome in Brazil and to investigate a possible association between vaccination and the clinical course and outcome of the disease. Methods Retrospective cohort study of hospitalized pregnant and postpartum women diagnosed with Severe Acute Respiratory Syndrome (SARS) by SARS-CoV-2, presenting onset of signs and symptoms between May and October 2021. Secondary data were used, available in the Influenza Epidemiological Surveillance Information System (SIVEP-Gripe). Data were analyzed using the SPSS statistical program, medians were applied to present continuous variables and frequencies, and proportions were calculated for categorical variables, using logistic and multivariate regression analysis. Results The final study population included 3,585 pregnant and postpartum women, of whom 596 (16.6) were vaccinated: 443 (74.3%) received one dose and 153 (25.7%) received two doses. They were factors associated with non-vaccination against Covid-19 age <= 19 anos (OR: 2.57; IC95% 1.40;4.71), non-white women (OR: 1.34; IC95% 1.07;1.67) and those who required ventilatory support (OR: 1.51; IC95% 1.19;1.90) and invasive ventilation (OR: 2.05; IC95% 1.37;3.08). On the other hand, vaccination was associated with advanced maternal age (OR: 0.60; IC95% 0.48;0.76), presence of comorbidities (OR: 0.57; IC95% 0.45;0.72) and loss of taste (OR: 0.63; IC95% 0.48;0.82). Conclusions Demographic, ethnic-racial and clinical characteristics were associated with the vaccination status of pregnant and postpartum women with SARS by SARS-CoV-2 in Brazil. Vaccination against Covid-19 in the obstetric population has already shown positive results in the evolution of severe cases, which reiterates its importance. It is essential that health services advance vaccination against Covid-19 in the obstetric population, especially adolescentes and non-white women.