LAUSR

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 7th, 2020-September 30th, 2020) and second wave (October 1st - April 17th, 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.