The findings provide novel information on the outcome in pregnancy that are counter to smaller reports.
Results of an observational cohort study from UT Southwestern in Dallas found that 95% of women with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy did not have a higher risk of experiencing adverse pregnancy outcomes. These findings, published in JAMA Network Open, offer new insight into existing research and contribute to further understanding of SARS-CoV-2 infection in pregnancy.
"We found that 5% of all delivered women with SARS-CoV-2 infection develop severe or critical illness, which is lower than previous reports," said the study's co-author and Contemporary OB/GYN editor-in-chief Catherine Y. Spong, MD.
The study included data of 3,374 pregnant women (mean [SD] age, 27.6  years) who were tested for SARS-CoV-2 infection and delivered between March 18 to August 22 at Parkland Health and Hospital System, a high-volume urban maternity care center with widespread access to SARS-CoV-2 testing in outpatient, emergency department, and inpatient settings. This included 252 women who were SARS-CoV-2 positive and 3,122 who were SARS-CoV-2 negative.1
Testing was performed for outpatient areas, and before May 14, 2020, for inpatient areas on the basis of symptoms (fever, cough, dyspnea, myalgia, loss of smell or taste, vomiting, diarrhea, or sore throat) or specific risk criteria. On May 14, the hospital system implemented a universal testing protocol in its labor and delivery unit. Women presenting for care with external positive testing results were included without repeat testing.
"The rate of hospitalization for the indication of COVID-19 is similar to that of non-pregnant women, at 6% (14/252) – markedly different than prior reports – in June 2020 the CDC reported 31.5% of pregnant women were hospitalized vs 5.8% of non-pregnant women," said Spong.
Neonatal testing protocols included SARS-CoV-2 testing at 24 and 48 hours among infants born within 4 weeks of maternal SARS-CoV-2 diagnosis, or when clinically indicated; admission to a neonatal intensive care unit isolation ward was routine for infants born to symptomatic mothers until maternal transmission-based precautions could be discontinued or until discharge.
Early neonatal SARS-CoV-2 infection occurred in 3% of tested infants, primarily among those born to asymptomatic or mildly symptomatic women.1
Researchers found no difference in outcomes of preterm birth, preeclampsia with severe features, or cesarean delivery for fetal indication among women with and without SARS-CoV-2 infection diagnosed during pregnancy (52 women [21%] vs 684 women [23%]; relative risk, 0.94; 95%CI, 0.73-1.21; P = .64).
According to study findings, maternal illness severity had no association with placental abnormalities. Findings did suggest, however, that that the risk of delivery at less than 37, 34, and 28 weeks increased with worsening maternal COVID-19 illness severity.
According to the results, 5% of all delivered women with SARS-CoV-2 infection present with or developed severe or critical illness. These findings, note the authors, are novel and lower than rates in previous reports.
The authors call for further research to understand whether maternal infection with SARS-CoV-2 is associated with long-term maternal or infant health.