The COVID-19 pandemic affects pregnancy complications and delivery outcomes in Japan: a large-scale nationwide population-based longitudinal study

The impact of the coronavirus disease 2019 (COVID-19) pandemic on pregnancy outcomes in Japan at the national level is unclear. This study aimed to assess the impact of the pandemic on pregnancy complications and delivery outcomes in Japan using nationwide population-based longitudinal data. Secondary data from the Japan Society of Obstetrics and Gynecology from 2016 to 2020 were analyzed. Obstetric information, pregnancy complications, and delivery information of pregnant women over 22 weeks of gestation were compared before and during the pandemic. The trends of hypertensive disorder of pregnancy, fetal growth restriction, and APGAR<7 increased, whereas those of preterm birth and low birth weight decreased during the COVID-19 pandemic. Pregnancy complications and delivery outcomes have worsened during the COVID-19 pandemic in Japan. Social changes caused by unprecedented situations may have massively influenced pregnancy in several ways. Our findings suggest that even in mild lockdowns like those in Japan, the introduction of social fear during the pandemic might negatively impact pregnancy outcomes.