Outcomes and proportions of pregnant females during the first and consecutively waves of COVID-19: observational cohort study

Kodde, Cathrin; Bonsignore, Marzia; Hohenstein, Sven; Kuhlen, Ralf; Meier-Hellmann, Andreas; Bollmann, Andreas; Nachtigall, Irit

OBJECTIVES: It has been suggested that pregnant females were affected more severely during the late, as opposed to the early wave of the COVID-19 pandemic. The aim of our study was to compare the proportion of pregnant females among hospitalized females in childbearing age, their rate of intensive care (ICU) admission, need for mechanical ventilation and mortality during the waves. METHODS: The study is a retrospective analysis of claims data on females in childbearing age (16 – 49y) admitted to 76 hospitals with a lab-confirmed SARS-CoV-2 infection. The observation period was divided into first (March 7(th), 2020-September 30(th), 2020) and second wave (October 1(st) - April 17(th), 2021). Comorbidities derived from claims data were summarized in the Elixhauser Comorbidity Index (ECI). RESULTS: 1,879 females were included, 532 of whom were pregnant. During the second wave, the proportion of pregnant females was higher (29.3% (484/1,650) vs. 21.0% (48/229), p<.01), they were older (mean ± standard deviation SD = 29.1±5.9 y vs. 27±6.3 y, p=.02 in the first wave) and had comparable comorbidities (ECI mean±SD=0.3±3.5 vs.–0.2±2.0 p=.30). 6.2% (3/48) of pregnant females were admitted to ICU during the first wave vs. 3.3% (16/484) during the second wave (odds ratio OR=0.51, 95% confidence interval CI=0.14–1.83, p=.30). 2.1% (1/48) were ventilated vs. 1.2% (6/484, OR=0.60, 95% CI=0.07–5.23, p=.64). No deaths were observed among the hospitalized pregnant females in either wave. CONCLUSIONS: Proportionally more pregnant females with COVID-19 were hospitalized in the second wave compared to the first wave but no more severe outcomes were registered.