ABSTRACT
Background: People's lifestyles may have changed during the COVID-19 pandemic, which may have a profound impact on pregnant women and newborns. This study aims to assess the effects of the COVID-19 pandemic on uninfected pregnant women and their newborns, including potential environmental factors. Methods: We retrospectively analyzed the pregnancy complications of 802 cases in the pandemic group and 802 controls in the pre-pandemic group in a matched nested case-control study, and evaluated the association with sociodemographic features, lifestyles, and other factors in 311 pregnant women with adverse pregnancy outcomes. Results: Compared to the pre-pandemic group, the rates of anemia, vaginitis, shoulder dystocia, and adverse pregnancy outcomes such as preterm birth were increased in the pandemic group. After controlling for the covariates, we observed a higher risk of adverse pregnancy outcomes in the pandemic group. Pregnant women with adverse pregnancy outcomes had an increased rate of anemia and vaginal candidiasis. Conclusion: COVID-19 pandemic has profound effects on adverse pregnancy outcomes, suggesting the importance of ensuring regular prenatal checkups and keeping a healthy lifestyle.