Objective To assess the incidence of uterine rupture, its association with previous uterine surgery and vaginal birth after a caesarean section (VBAC), and the maternal and perinatal implications. Design Population-based retrospective study. Setting Shanghai, China. Participants A total of 209,112 deliveries were attended and 41 uterine rupture cases were included. Methods All pregnant women treated for ruptured uterus in one center between 2013 and 2020 were included. Their case folders retrieved from the medical records room were retrospectively reviewed. Main outcome measure Adverse maternal and neonatal outcomes. Results The incidence of uterine rupture was 1.96/10 000 births. 16 (39.0%) had maternal and fetal complications. There were no maternal deaths secondary to uterine rupture, while perinatal mortality attributable to uterine rupture was 7.32 %. Among all case, 38 (92.68%) were scarred uterus and 3(7.32%) were unscarred uterus. The most common cause of uterine rupture was previous cesarean section while cases with a history of laparoscopic myomectomy often had serious adverse outcome. 24 (59%) of ruptures were anterior lower uterine segment. Fetal heart rate monitoring changes are the most reliable presenting clinical symptom in our study. Conclusion Incidence of uterine rupture in the study area was consistent with developed countries. Further improvement in obstetric care and strong collaboration with referring health facilities was needed to ensure maternal and perinatal safety.

Objective: To investigate reliable biomarkers for predicting histological chorioamnionitis (HCA). Design: In this retrospective study, PPROM mothers were treated with a course of dexamethasone. Blood tests for serum indictors were conducted continuously after first injection. Setting: One Shanghai hospital Population: PPROM mothers before 34 0/7 weeks of gestation Methods: Data were compared by General Linear Model analysis. The diagnostic accuracy in predicting HCA were evaluated with ROC curve. Main Outcome Measures: The response of infectious indictors to dexamethasone treatment; the diagnostic accuracy for CRP and PCT in predicting HCA. Results： We found 98 HCA women (62.42%) and 59 CON women (37.58%) in 157 PPROM mothers. WBC and neutrophil significantly increased 24 hours after the first injection in both groups, followed by a decrease at 72 hours post first injection (P<0.05). No significances were found between two groups in WBC, neutrophil and lymphocyte. Both CRP and PCT were significantly higher in the HCA group after first injection. PCT had both high specificity and sensitivity, especially at the baseline (cutoff, 0.031 ng/ml). Furthermore, the positive predictive values (PPV) of PCT were respectively 0.946 and 0.960 at 48 (cutoff, 0.049 ng/ml) and 72 (cutoff, 0.051 ng/ml) hours, which were better than the corresponding PPV of CRP. Conclusion: The response of WBC, neutrophil and lymphocyte to dexamethasone could be differentiated from uterine infection; PCT could be a reliable biomarker for early diagnosis of HCA. Funding: Shanghai Municipal Commission of Health and Family Planning (GWIV-26, 202040128); Pudong Commission of Health and Family Planning (PW2019D-13).