Increased Risk of Severe COVID-19 Disease in Pregnancy in a Multicenter Propensity Score-Matched Study

Background

Respiratory infections have long been associated with higher maternal and perinatal morbidity. Early data did not report an increased risk of SARS-CoV-2 infection or disease severity in pregnancy. However, surveillance data from the Center for Disease Control and Prevention (CDC) indicates a higher risk of severe disease and death in pregnant women with symptomatic SARS-CoV-2 infection, although this data is subject to ascertainment bias.

Objective

To explore the association between COVID-19 disease severity and pregnancy in our university-based hospital system using measures such as COVID-19 ordinal scale severity score, hospitalization, intensive care unit admission, oxygen supplementation, invasive mechanical ventilation, and death.

Study design

We conducted a retrospective, multicenter case-control study to understand the association between COVID-19 disease severity and pregnancy. We reviewed consecutive charts of adult females, ages 18-45, with laboratory-confirmed SARS-CoV-2 infection in six months between March 1, 2020, and August 31, 2020. Cases were patients diagnosed with COVID-19 during pregnancy, whereas controls were not pregnant at the time of COVID-19 diagnosis. Primary endpoints were the COVID-19 severity score at presentation (within four hours) and the nadir of the clinical course. The secondary endpoints were the proportion of patients requiring hospitalization, intensive care unit admission, oxygen supplementation, invasive mechanical ventilation, and death.

Results

A higher proportion of pregnant women had moderate to severe COVID-19 disease at the nadir of the clinical course than nonpregnant women (25% vs. 16.1%, p=0.04, respectively). While there was a higher rate of hospitalization (25.6% vs. 17.2%), ICU admission (8.9% vs. 4.4%), need for vasoactive substances (5.0% vs. 2.8%), and invasive mechanical ventilation (5.6% vs. 2.8%) in the pregnant group, this difference was not significant after the propensity score matching was applied.

We found a high rate of pregnancy complications in our population (40.7%). The most worrisome is the rate of hypertensive disorders of pregnancy (20.1%).

Conclusions

In our propensity score-matched study, COVID-19 in pregnancy is associated with an increased risk of disease severity and an increased risk of pregnancy complications.