Pregnancy outcomes in Italy during COVID-19 pandemic: a population-based cohort study

Objective. To compare the estimates of preterm birth (PTB; 22-36 weeks gestational age, GA) and stillbirth rates during COVID-19 pandemic in Italy with those recorded in the three previous years. Design. A population-based cohort study of liveborn and stillborn infants was conducted using data from Regional Health Systems and comparing the pandemic period (March 1st, 2020-March 31st, 2021, N= 362,129) to an historical period (January 2017- February 2020, N=1,117,172). The cohort covered 84.3% of the births in Italy. Methods. Logistic regressions were run in each Region and meta-analyses were performed centrally. We used an interrupted time series regression analysis to study the trend of preterm births from 2017 to 2021. Main Outcome Measures. The primary outcomes were PTB and stillbirths. Secondary outcomes were late PTB (32-36 weeks’ GA), very PTB (