Objective To investigate the incidence of placental abruption in the third trimester of pregnancy in Hebei Province,identify its associated risk factors,and develop a corresponding nomogram prediction model.Methods Data from pregnant women at 22 monitored hospitals in Hebei Province,collected between 2013 and 2023,were analyzed to assess the incidence,trends,and associated risk factors of placental abruption.A prediction model was developed and visualized using R programming to generate the receiver operating characteristic(ROC)curve.The model's predictive performance was evaluated using the area under the curve(AUC)and calibration curve parameters.Results A total of 480 690 pregnant women were included in this study over the specified period.The incidence of placental abruption was 0.29%(1 395 out of 480 690),with an average annual percentage change of 2.73%,indicating a stable trend(P=0.34).Multivariate logistic regression analysis revealed that pregnancy-related anemia,preeclampsia,placenta previa,vaginal bleeding before 28 weeks'gestation,and between 28 and 31+6 weeks'gestation were significant risk factors for placental abruption(all P<0.05).In contrast,regular prenatal examinations(7～11 visits)and multiple pregnancies were identified as protective factors against placental abruption(both P<0.05).The area under the curve(AUC)for the nomogram model constructed based on independent risk factors for placental abruption was 0.79,and the calibration curve demonstrated that the predicted values closely aligned with the observed values.Conclusions Prenatal examinations should be prioritized,especially for women with preeclampsia,placenta previa,or a history of vaginal bleeding before 28 weeks of gesta-tion.Management of pregnancies between 28 and 31+6 weeks is also crucial to reduce the incidence of placental abruption and mitigate adverse maternal and neonatal outcomes.The nomogram model constructed based on these factors exhibits excellent predictive performance,providing a solid theoretical foundation for the prevention and clinical management of placental abruption.

Objective To investigate the incidence of placental abruption in the third trimester of pregnancy in Hebei Province,identify its associated risk factors,and develop a corresponding nomogram prediction model.Methods Data from pregnant women at 22 monitored hospitals in Hebei Province,collected between 2013 and 2023,were analyzed to assess the incidence,trends,and associated risk factors of placental abruption.A prediction model was developed and visualized using R programming to generate the receiver operating characteristic(ROC)curve.The model's predictive performance was evaluated using the area under the curve(AUC)and calibration curve parameters.Results A total of 480 690 pregnant women were included in this study over the specified period.The incidence of placental abruption was 0.29%(1 395 out of 480 690),with an average annual percentage change of 2.73%,indicating a stable trend(P=0.34).Multivariate logistic regression analysis revealed that pregnancy-related anemia,preeclampsia,placenta previa,vaginal bleeding before 28 weeks'gestation,and between 28 and 31+6 weeks'gestation were significant risk factors for placental abruption(all P<0.05).In contrast,regular prenatal examinations(7～11 visits)and multiple pregnancies were identified as protective factors against placental abruption(both P<0.05).The area under the curve(AUC)for the nomogram model constructed based on independent risk factors for placental abruption was 0.79,and the calibration curve demonstrated that the predicted values closely aligned with the observed values.Conclusions Prenatal examinations should be prioritized,especially for women with preeclampsia,placenta previa,or a history of vaginal bleeding before 28 weeks of gesta-tion.Management of pregnancies between 28 and 31+6 weeks is also crucial to reduce the incidence of placental abruption and mitigate adverse maternal and neonatal outcomes.The nomogram model constructed based on these factors exhibits excellent predictive performance,providing a solid theoretical foundation for the prevention and clinical management of placental abruption.