Background: COVID-19 may be associated with adverse maternal and neonatal outcomes in pregnancy, but there is little controlled data to quantify the magnitude of these risks or to characterize the epidemiology and risk factors.
Objective: To quantify the associations of COVID-19 with adverse maternal and neonatal outcomes in pregnancy and to characterize the epidemiology and risk factors.
Methods: We performed a matched case-control study of pregnant patients with confirmed COVID-19 (cases) who delivered between 16 and 41 weeks’ gestation from March 11-June 11, 2020. Uninfected pregnant women (controls) were matched to COVID-19 cases on a 2:1 ratio based on delivery date. Maternal demographic characteristics, COVID-19 symptoms, laboratory evaluations, obstetrical and neonatal outcomes, and clinical management were chart abstracted. The primary outcomes included (i) a composite of adverse maternal outcome, defined as preeclampsia, venous thromboembolism, antepartum admission, maternal intensive care unit admission, need for mechanical ventilation, supplemental oxygen, or maternal death; and (ii) a composite of adverse neonatal outcome, defined as respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, five-minute Apgar score <5, persistent category 2 fetal heart rate tracing despite intrauterine resuscitation, or neonatal death. In order to quantify the associations between exposure to mild and severe/critical COVID-19 and adverse maternal and neonatal outcomes, unadjusted and adjusted analyses were performed using conditional logistic regression (to account for matching), with matched-pair odds ratio (OR) and 95% confidence interval (CI) based on 1000 bias-corrected bootstrap resampling as the effect measure. Associations were adjusted for potential confounders.
Results: 61 confirmed COVID-19 cases were enrolled during the study period (mild disease: n=54, 88.5%; severe disease: n=6, 9.8%; and critical disease: n=1, 1.6%). The odds of adverse composite maternal outcome were 3.4 times higher among cases compared to controls (18.0% versus 8.2%, adjusted OR 3.4, 95% CI 1.2-13.4). The odds of adverse composite neonatal outcome were 1.7 times higher in the case group compared to the control group (18.0% versus 13.9%, adjusted OR 1.7, 95% CI 0.8-4.8). Stratified analyses by disease severity indicated that the morbidity associated with COVID-19 in pregnancy was largely driven by the severe/critical disease phenotype. Major risk factors for associated morbidity were Black and Hispanic race, advanced maternal age, medical comorbidities, and antepartum admissions related to COVID-19.
Conclusions: COVID-19 during pregnancy is associated with increased risk for adverse maternal and neonatal outcomes, an association that is primarily driven by morbidity associated with severe/critical COVID-19. Black and Hispanic race, obesity, advanced maternal age, medical comorbidities, and antepartum admissions related to COVID-19 are risk factors for associated morbidity.