Physiologic adaptations and changes in immune regulation may increase the risk of morbidity and mortality in pregnant women with respiratory infections.1,2 The effects of coronavirus disease 2019 (COVID-19) in pregnancy have not been fully delineated. We compared the clinical characteristics and outcomes of hospitalized women who gave birth with and without COVID-19.
Women giving birth and discharged between April 1 and November 23, 2020, were identified by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes within the Premier Healthcare Database, an all-payer database encompassing approximately 20% of US hospitalizations.3 Race and ethnicity were self-reported, and COVID-19 status (ICD-10 code U07.1), comorbidities, and in-hospital outcomes were identified using ICD-10 and billing codes (eTables 1 and 2 in the Supplement). Discharge disposition and in-hospital death were reported in all patients.
Data were collected and deidentified by Premier Inc, which curates the Premier Healthcare Database, then analyzed at Brigham and Women’s Hospital in Boston, Massachusetts. The Mass General Brigham Institutional Review Board approved the study protocol and waived the requirement for patient informed consent. Multivariable logistic regression was used to derive a propensity model estimating the probability of COVID-19 (eMethods in the Supplement). Associations between COVID-19 and in-hospital outcomes were examined using propensity score-adjusted regression. Factors associated with in-hospital death or mechanical ventilation use among pregnant women with COVID-19 were identified using forward stepwise logistic regression (eMethods in the Supplement). Analyses were conducted using Stata, version 15.0 (Stata Corp) with a 2-tailed P value less than .05 considered significant. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.4
Among the 406 446 women hospitalized for childbirth over the 8 months of the study, 6380 (1.6%) had COVID-19. Compared with pregnant women without COVID-19 (n = 400 066), the women with COVID-19 were younger and more often Black and/or Hispanic and with diabetes and obesity (Table 1).
Of the 6380 women with COVID-19 who gave birth, 6309 (98.9%) were discharged to home, 212 (3.3%) needed intensive care, 86 (1.3%) needed mechanical ventilation, and 9 (0.1%) died in the hospital (Table 2). Although in-hospital mortality was low, it was significantly higher in the women with COVID-19 than in those without COVID-19 (141 [95% CI, 65-268] vs 5.0 [95% CI, 3.1-7.7] deaths per 100 000 women). Rates of myocardial infarction and venous thromboembolism (VTE) were higher in the women with COVID-19 who gave birth than in those without COVID-19 (myocardial infarction: 0.1% vs 0.004%; VTE: 0.2% vs 0.1%; P < .001). COVID-19 was associated with higher odds of preeclampsia (adjusted odds ratio [aOR], 1.21 [95% CI, 1.11-1.33]) and preterm birth (aOR, 1.17 [95% CI, 1.06-1.29]) but not with significantly higher odds of stillbirth (aOR, 1.23 [95% CI, 0.87-1.75]). Use of chest imaging, intensive care treatment, and mechanical ventilation was higher among the women who gave birth with COVID-19 compared with those without COVID-19 (Table 2).
Among women with COVID-19 who gave birth, age (OR, 1.91 [95% CI, 1.31-2.77] per 10 years), morbid obesity (OR, 3.85 [95% CI, 2.05-7.21]), diabetes (OR, 4.51 [95% CI, 2.10-9.70]), kidney disease (OR, 21.57 [95% CI, 7.73-60.10]), eclampsia (OR, 116.1 [95% CI, 22.91-588.50]), thrombotic events (OR, 45.10 [95% CI, 17.13-118.8]), and stillbirth (OR, 7.88 [95% CI, 2.39-25.98]) were associated with higher odds of mechanical ventilation use or in-hospital death.