Objective:To investigate the incidence of common complications following vaginal delivery and analyze their influencing factors among women of reproductive age.Methods:This prospective cohort study consecutively enrolled women who delivered vaginally at two campuses of the Obstetrics and Gynecology Hospital of Fudan University between February and July 2023. Participants were categorized into groups according to complication occurrence: those with obstetric laceration versus those without, postpartum hemorrhage versus non-hemorrhage, and retained placenta/membranes without hemorrhage vs. non-retention. Data were collected using a self-developed questionnaire on risk factors for vaginal delivery complications. Group comparisons of demographics, obstetric history, intrapartum assessments, and delivery outcomes were performed using Chi-square test (or Fisher's exact test), independent samples t-test, and Mann-Whitney U test. Multivariate logistic regression identified risk factors for the three complication types. Results:Among 1 966 vaginal deliveries, the overall complication rate was 8.1% (159/1 966), with obstetric lacerations representing the most frequent complication at 4.6% (91/1 966), followed by postpartum hemorrhage at 2.7% (53/1 966) and retained placenta/membranes without hemorrhage at 1.4% (27/1 966). Multivariate logistic regression analysis identified distinct sets of independent risk factors for each complication. For obstetric lacerations, adequate gestational weight gain was associated with a reduced risk ( OR=0.547, 95% CI: 0.332-0.900, P=0.018), while precipitous labor ( OR=2.633, 95% CI: 1.321-5.248, P=0.006), shoulder dystocia ( OR=2.495, 95% CI: 1.093-5.691, P=0.030), poor maternal cooperation ( OR=1.887, 95% CI: 1.061-3.359, P=0.031), and specific perineal conditions—particularly reduced skin folds ( OR=2.341, 95% CI: 1.247-4.395, P=0.008) and tight/thick/edematous skin ( OR=2.511, 95% CI: 1.248-5.054, P=0.010)—emerged as significant risk factors. Regarding postpartum hemorrhage, conception through assisted reproductive technology ( OR=3.286, 95% CI: 1.189-9.076, P=0.022), presence of obstetric comorbidities ( OR=2.460, 95% CI: 1.070-5.656, P=0.034), elevated D-dimer levels ( OR=1.157, 95% CI: 1.049-1.277, P=0.004), reduced fibrinogen ( OR=0.521, 95% CI: 0.319-0.851, P=0.009), weak uterine contractions ( OR=20.175, 95% CI: 10.352-39.321, P<0.001), abnormal placentation ( OR=2.434, 95% CI: 1.167-5.078, P=0.018), and absence of early skin-to-skin contact ( OR=0.141, 95% CI: 0.067-0.295, P<0.001) were independently associated with increased risk. For retained placenta/membranes without hemorrhage, prolonged thrombin time ( OR=0.117, 95% CI: 0.034-0.318, P<0.001) and abnormal placentation ( OR=51.843, 95% CI: 14.988-179.324, P<0.001) were identified as primary risk factors. Conclusions:While the overall incidence of complications following vaginal delivery among women of reproductive age is relatively low, high-risk groups warrant particular attention. Precipitous labor, shoulder dystocia, poor maternal cooperation, and unfavorable perineal conditions increase laceration risk. Assisted conception, obstetric comorbidities, elevated D-dimer levels, uterine atony, and placental abnormalities elevate hemorrhage risk. Furthermore, placental abnormalities are strongly associated with retained placenta/membranes without hemorrhage.

Objective:To investigate the incidence of common complications following vaginal delivery and analyze their influencing factors among women of reproductive age.Methods:This prospective cohort study consecutively enrolled women who delivered vaginally at two campuses of the Obstetrics and Gynecology Hospital of Fudan University between February and July 2023. Participants were categorized into groups according to complication occurrence: those with obstetric laceration versus those without, postpartum hemorrhage versus non-hemorrhage, and retained placenta/membranes without hemorrhage vs. non-retention. Data were collected using a self-developed questionnaire on risk factors for vaginal delivery complications. Group comparisons of demographics, obstetric history, intrapartum assessments, and delivery outcomes were performed using Chi-square test (or Fisher's exact test), independent samples t-test, and Mann-Whitney U test. Multivariate logistic regression identified risk factors for the three complication types. Results:Among 1 966 vaginal deliveries, the overall complication rate was 8.1% (159/1 966), with obstetric lacerations representing the most frequent complication at 4.6% (91/1 966), followed by postpartum hemorrhage at 2.7% (53/1 966) and retained placenta/membranes without hemorrhage at 1.4% (27/1 966). Multivariate logistic regression analysis identified distinct sets of independent risk factors for each complication. For obstetric lacerations, adequate gestational weight gain was associated with a reduced risk ( OR=0.547, 95% CI: 0.332-0.900, P=0.018), while precipitous labor ( OR=2.633, 95% CI: 1.321-5.248, P=0.006), shoulder dystocia ( OR=2.495, 95% CI: 1.093-5.691, P=0.030), poor maternal cooperation ( OR=1.887, 95% CI: 1.061-3.359, P=0.031), and specific perineal conditions—particularly reduced skin folds ( OR=2.341, 95% CI: 1.247-4.395, P=0.008) and tight/thick/edematous skin ( OR=2.511, 95% CI: 1.248-5.054, P=0.010)—emerged as significant risk factors. Regarding postpartum hemorrhage, conception through assisted reproductive technology ( OR=3.286, 95% CI: 1.189-9.076, P=0.022), presence of obstetric comorbidities ( OR=2.460, 95% CI: 1.070-5.656, P=0.034), elevated D-dimer levels ( OR=1.157, 95% CI: 1.049-1.277, P=0.004), reduced fibrinogen ( OR=0.521, 95% CI: 0.319-0.851, P=0.009), weak uterine contractions ( OR=20.175, 95% CI: 10.352-39.321, P<0.001), abnormal placentation ( OR=2.434, 95% CI: 1.167-5.078, P=0.018), and absence of early skin-to-skin contact ( OR=0.141, 95% CI: 0.067-0.295, P<0.001) were independently associated with increased risk. For retained placenta/membranes without hemorrhage, prolonged thrombin time ( OR=0.117, 95% CI: 0.034-0.318, P<0.001) and abnormal placentation ( OR=51.843, 95% CI: 14.988-179.324, P<0.001) were identified as primary risk factors. Conclusions:While the overall incidence of complications following vaginal delivery among women of reproductive age is relatively low, high-risk groups warrant particular attention. Precipitous labor, shoulder dystocia, poor maternal cooperation, and unfavorable perineal conditions increase laceration risk. Assisted conception, obstetric comorbidities, elevated D-dimer levels, uterine atony, and placental abnormalities elevate hemorrhage risk. Furthermore, placental abnormalities are strongly associated with retained placenta/membranes without hemorrhage.