Abstract
<title>Abstract</title> <p> Objective To explore placenta previa (PP) incidence trends and its effects on maternal perinatal features and pregnancy outcomes. Methods A multicenter retrospective nested-case-control study analyzed 195,440 pregnant women delivering in three Hangzhou tertiary hospitals from 2014 to 2023. A total of 1,939 cases in the PP group and 1,982 cases in the non-PP group were randomly selected. Chi-square tests were used for univariate comparisons, while multivariate logistic regression evaluated PP risk factors. Results The incidence of PP among pregnant women decreased from 2.71% in 2014 to 0.60% in 2023, stabilizing between 0.60% and 1.00%. Significant differences in PP incidence were observed for factors such as floating population, urban/rural household registration, gravidity, parity, length of hospital stay, mode of delivery, gestational age at delivery, hypertensive disorders of pregnancy (HDP), and year of delivery (all <italic>P</italic> < 0.05). Multivariate logistic regression analysis revealed an increased risk of PP in elderly pregnant women (≥ 35 years old) (aOR = 1.47), with higher risks observed in non-Hangzhou floating populations (aOR = 85.66) and rural populations (aOR = 1.36). The risk of PP increased with gravidity and parity. The occurrence of PP was associated with an increased risk of cesarean section (aOR = 83.54) and prolonged hospital stay (aOR = 1.38). Conclusion The incidence of PP in Hangzhou is 0.99%. Affected by perinatal characteristics and other factors, PP poses significant risks to pregnancy outcomes. Early monitoring and treatment of PP should be implemented to reduce adverse pregnancy outcomes. </p>