Contracting COVID-19 during pregnancy may put expectant mothers at a higher risk of delivering early, according to new data from the U.S. CDC. The CDC’s new report is based on data from almost 4,500 people who were diagnosed with COVID-19 during pregnancy and provided public health departments with information about their pregnancy outcomes. Roughly 3,900 mothers gave information about their baby’s gestational age. Within that group, nearly 13% of babies (about 500) were born preterm—slightly but significantly higher than the 2019 national rate of about 10%.