Delivery outcomes in a cohort of pregnant patients with COVID-19 with and without viral pneumonia

Abstract

Among pregnant people, COVID-19 can lead to adverse outcomes, but the specific pregnancy outcomes that are affected by the disease are unclear. In addition, the effect of the severity of COVID-19 on pregnancy outcomes has not been clearly identified. This study aimed to evaluate the associations between COVID-19 with and without viral pneumonia and cesarean delivery, preterm delivery, preeclampsia, and stillbirth. We conducted a retrospective cohort study (April 2020-May 2021) of deliveries between 20 and 42 weeks of gestation from US hospitals in the Premier Healthcare Database. The primary outcomes were cesarean delivery, preterm delivery, preeclampsia, and stillbirth. We used a viral pneumonia diagnosis (International Classification of Diseases -Tenth-Clinical Modification codes J12.8 and J12.9) to categorize patients by severity of COVID-19. Pregnancies were categorized into 3 groups: NOCOVID (no COVID-19), COVID (COVID-19 without viral pneumonia), and PNA (COVID-19 with viral pneumonia). Groups were balanced for risk factors by propensity-score matching. A total of 814,649 deliveries from 853 US hospitals were included (NOCOVID: n=799,132; COVID: n=14,744; PNA: n=773). After propensity-score matching, the risks of cesarean delivery and preeclampsia were similar in the COVID group compared with the NOCOVID group (matched risk ratio, 0.97; 95% confidence interval, 0.94-1.00; and matched risk ratio, 1.02; 95% confidence interval, 0.96-1.07; respectively). The risks of preterm delivery and stillbirth were greater in the COVID group than in the NOCOVID group (matched risk ratio, 1.11; 95% confidence interval, 1.05-1.19; and matched risk ratio, 1.30; 95% confidence interval, 1.01-1.66; respectively). The risks of cesarean delivery, preeclampsia, and preterm delivery were higher in the PNA group than in the COVID group (matched risk ratio, 1.76; 95% confidence interval, 1.53-2.03; matched risk ratio, 1.37; 95% confidence interval, 1.08-1.74; and matched risk ratio, 3.33; 95% confidence interval, 2.56-4.33; respectively). The risk of stillbirth was similar in the PNA and COVID group (matched risk ratio, 1.17; 95% confidence interval, 0.40-3.44). Within a large national cohort of hospitalized pregnant people, we found that the risk of some adverse delivery outcomes was elevated in people with COVID-19 with and without viral pneumonia, with much higher risks in the group with viral pneumonia.