Effects of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) Delta variant (B.1.617.2) on maternal and neonatal outcomes

Coronavirus 2019 (COVID-19) infection during pregnancy has been reported to increase the risk of adverse maternal and perinatal outcomes. Data from the general population suggests that the Delta variant infection is associated with more severe disease than the Alpha variant. However, there is limited data available on the impact of delta variant infection during pregnancy on perinatal outcomes. This study aimed to evaluate the effects of SARS-CoV-2 delta variant infection during pregnancy on maternal and neonatal outcomes. In this retrospective, single-center study, we included all infants who were born from May 2020 through October 2021 to mothers with COVID-19 infection during pregnancy. At our institution, we started inpatient testing of all obstetric patients on admission on May 29, 2020. In our region, the Delta variant accounted for more than 80% of all COVID-19 infections from July 2021. Maternal and neonatal outcomes were compared between the pre-Delta (May 2020–June2021, n = 20) and Delta groups (July 2021–October 2021, n = 52). In comparing the Pre-Delta to Delta groups, there were no significant differences in the rates of maternal chorioamnionitis, gestational hypertension, diabetes, antepartum bleeding, c-section, maternal ICU admission, maternal COVID-19 symptoms, and maternal survival. All neonates born to these mothers tested negative for COVID-19. The rates of premature birth, Apgar score of less than 5 at 5 minutes, small for gestational age, microcephaly, need for noninvasive or invasive ventilator support, hypoxic ischemic encephalopathy, culture positive sepsis, and neonatal survival were not different between the two groups. There was no difference in placental findings between the two groups. However, infants born to symptomatic mothers in the Delta group had a higher rate of preterm delivery. Based on our study, the Delta variant of COVID-19 can increase preterm birth rates among symptomatic mothers. Further meta-analysis of available studies is needed to evaluate its effect on neonatal outcomes.