Stillbirth and Preterm Birth During Lockdown Periods in 5 Waves of COVID-19 Pandemic in Northern Iran: A Region-Wide Cohort Study in Mazandaran Province

Abstract

Introduction: Conflicting reports for preterm birth and stillbirth during the lockdown imposed during the COVID-19 pandemic have emerged. Most of the studies are related to the initial waves of the pandemic. Objectives: This study aims to evaluate changes in preterm birth and stillbirth rates during various waves of COVID-19 in northern Iran. Methods: This is a retrospective cohort study to evaluate preterm birth and stillbirth rate based on weight distribution per 1000 live births during lockdown periods in 5 peaks of the COVID-19 pandemic using the regional data registration system at Mazandaran University of Medical Sciences in northern Iran. We compared these rates with the corresponding months 4 years before the pandemic. The odds ratio for the primary outcome was estimated by logistic regression. Results: We observed an overall increased rate of preterm birth during the pandemic compared to the pre-pandemic period (4.7% vs 2.8%, P