Background: The SARS-CoV-2 pandemic and associated social, economic, and clinical disruption have been widely speculated to affect pregnancy decision-making and outcomes . While a few US-based studies have examined subnational changes in fertility, preterm birth, and stillbirth, there remains limited knowledge of how the pandemic impacted childbearing and a broader set of perinatal health indicators at the national-level throughout 2020 . Here, we use recently released national-level data to fill this gap . Importantly, we, unlike earlier work, use time-series methods to account for strong temporal patterning (e.g., seasonality, trend) that could otherwise lead to spurious findings .
Methods: For the years 2015 to 2020, we obtained national monthly counts of births and rates (per 100 births) for six perinatal indicators: preterm birth (< 37 weeks gestation), early preterm birth (< 34 weeks gestation), late preterm birth (34-36 weeks gestation), low birth weight birth (< 2500 g), very low birth weight birth (< 1500 g), and cesarean delivery . We use an interrupted time-series approach to compare the outcomes observed after the pandemic began (March 2020) to those expected had the pandemic not occurred .
Results: For total births as well as five of the six indicators (i.e., all but the rate of cesarean delivery), observed values fall well below expected levels (p <.0001 for each test) during the entire pandemic period . Declines in preterm birth and low birth weight were largest in magnitude in both early and later stages of the 2020 pandemic, while those for live births occurred at the end of the year .
Discussion: Our findings provide some of the first national evidence of substantial reductions in live births and adverse perinatal outcomes during the SARS-CoV-2 pandemic . Only cesarean delivery appeared unaffected . These declines were not uniform across the pandemic, suggesting that several mechanisms, which require further study, may explain these patterns.