Are in-hospital COVID-19-related mortality and morbidity in pregnancy associated with gestational age?

Abstract

Objective: Pregnancy involves dynamic changes in the maternal immune system, thus potentially affecting women's response to infection. The aim of this study was to investigate whether gestational age at the time of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with mortality and morbidity related to coronavirus disease 2019 (COVID-19) in hospitalized pregnant women.

Methods: This was a cohort study of pregnant women with confirmed SARS-CoV-2 infection at any gestational age (categorized into trimesters) who were hospitalized in Brazil from February 2020 to November 2021. Sociodemographic and epidemiological characteristics, signs and symptoms, comorbidities, interventions, vaccination status and type of healthcare establishment were obtained from a nationwide database. Multivariate logistic and Cox regression analyses were used to identify independent risk factors for in-hospital COVID-19-related mortality and morbidity (defined as time from hospital admission to recovery).

Results: A total of 7461 SARS-CoV-2-infected pregnant women were included in the study (9.3%, 28.4% and 62.3% in the first, second and third trimesters, respectively). After adjustment for sociodemographic, epidemiological and clinical characteristics, and intervention-related variables, gestational age at infection was found not to be associated with COVID-19-related mortality and morbidity. Women admitted to establishments with an obstetric center, compared to hospitals without, were 38% less likely to die from SARS-CoV-2 infection (adjusted odds ratio, 0.62; 95% CI, 0.48-0.80), while patients who received private not-for-profit healthcare had a 13% shorter time to recovery (adjusted hazard ratio, 1.13; 95% CI, 1.07-1.20) compared to those who received public healthcare.

Conclusions: Despite a higher percentage of women being admitted in the third trimester, we found no association between gestational age and COVID-19 mortality and morbidity. The previously reported increase in morbidity and mortality in the third trimester in pregnant women with COVID-19 may be attributable to other gestational-age-affected variables for which adjustment was made in our study. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Keywords: COVID-19; SARS-CoV-2; gestational age; morbidity; mortality; trimester.

Figure 1

Flowchart showing inclusion in study cohort of pregnant women who were hospitalized with confirmed SARS‐CoV‐2 infection in Brazil from February 2020 to November 2021. PCR, polymerase chain reaction.

Figure 2

Multivariate logistic regression analysis of predictors of in‐hospital mortality in pregnant women who were hospitalized with confirmed SARS‐CoV‐2 infection in Brazil. ICU, intensive care unit. , crude odds ratio; , adjusted odds ratio.

Figure 3

Multivariate Cox regression analysis of predictors of time from hospital admission to recovery in pregnant women with confirmed SARS‐CoV‐2 infection in Brazil. ICU, intensive care unit. , crude hazard ratio; , adjusted hazard ratio.