Objective:To study the influence of placental morphology and pathological changes on neonatal outcome in patients with premature rupture of membranes(PROM).Methods:100 parturients with PROM were selected as the study group,and 100 nor-mal parturients without PROM during the same period were selected as the control group.HE staining was used to observe the Placental pathological changes and monitor pregnancy outcome.The Placental pathological changes and pregnancy outcome were compared be-tween the two groups.The influencing factors of premature rupture of membranes were analyzed by Single factor and multiple factor Lo-gistic regression analysis.Results:The incidence of placental pathological changes in the study group was higher(P＜0.05).The inci-dence of adverse pregnancy outcome in the study group was higher than that in the control group(23.00%vs.5.00%,P＜0.05).Uni-variate analysis showed that there were no statistically significant difference in the incidence of uterine malformations,cervical dysfunc-tion,polyhydramnios,anemia during pregnancy,placenta previa,and history of induced labor or miscarriage between the two groups(P>0.05).In the study group,gestational diabetes,hypertension,abnormal fetal position,multiple births,reproductive tract infection and unknown causes were all higher(P＜0.05).Logistic regression analysis showed that the abnormal fetal position,multiple births,and reproductive tract infection were all independent risk factors for premature rupture of membranes(P＜0.05).Conclusion:Prema-ture rupture of membranes is affected by abnormal fetal position,multiple pregnancies,and reproductive tract infections,and the placenta of patients with premature rupture of membranes has pathological changes,which will lead to poor neonatal outcome.