Background: Emergency cervical cerclage (ECC) is of potential value in twin pregnancy, when the cervix is dilated to >1cm. McDonald and Shirodkar were two main techniques of transvaginal cerclage at present. As ECC at extremely high risk of spontaneous preterm birth (sPTB) especially for twins with cervical dilated ≥ 3cm and prolapsed membranes, so which technique has more advantages is still uncertain. Objectives: The aim of our study was to evaluate the effectiveness of ECC performed with combined McDonald-Shirodkar technique in twin pregnancies between 18–26 weeks with painless cervical dilation 1-6cm. Methods: A retrospective, cohort study matched with the degree of cervical dilation was conducted. The study group (case group) included twin pregnancies who underwent combined McDonald-Shirodkar approach with cervical dilation ≥1 cm between 18–26 weeks of gestation at four institutions, from December 2015 to December 2022. To minimize confounding factors, we elucidated the causality structure using a DAG (Figure 1) and performed 1:1 case-control Matching. A control group performed McDonald approach. The primary outcome was gestational age (GA) at delivery. The secondary outcomes were pregnancy latency, the rates of sPTB at <28, <30, <32, <34 weeks, and neonatal outcomes. Additional sub-analysis was performed by dividing the patients into two subgroups of cervical dilation ≥ 3cm and < 3cm. Results: 84 twin pregnancies were managed with either combined McDonald-Shirodkar approach (case group: n=42) or McDonald approach (control group: n=42). Demographic characteristics were not significantly different in two groups(p>0.05). After adjusting for confounders which were represented by a directed acyclic graph (DAG, Figure 1), median GA at delivery was significantly higher (30.5 vs 27 weeks, Bate: 3.40, 95% confidence interval (CI): 2.13-4.67, p<0.001) and median pregnancy latency was significantly longer (56 vs 28 days, Bate: 24.04, 95% CI: 13.31-34.78, p<0.001) in the case group compared with the control group. Rates of sPTB at <28, <30, <32, and <34 weeks were significantly lower in the case group than in the control group. For neonatal outcomes, there were higher birth weight (BW) (1543.75 vs 980g, Bate: 420.08, 95%CI: 192.18-647.98, p<0.001) and significantly lower overall perinatal mortality (7.1% vs 31%, aOR: 0.16, 95% CI: 0.04-0.70, p=0.014) in the case group compared with the control group. And when cervical dilation ≥ 3cm, combined McDonald-Shirodkar procedure can significantly reduce perinatal mortality (8.3% vs 46.7%, aOR:0.09, 95%CI: 0.01-0.77, p=0.028), significantly decrease the risk of delivery at <28, <30weeks, prolong GA at delivery and pregnancy latency compared with McDonald procedure. Conclusions: ECC performed with the combined McDonald-Shirodkar procedure in twin pregnancies with cervical dilation 1-6 cm in mid-trimester pregnancy may reduce the rate of sPTB and improve perinatal and neonatal outcomes compared with McDonald procedure, especially for twins with cervical dilation of 3-6 cm and prolapsed membranes.

Objective: To develop the prediction models for identifying fetal occiput rotation and vaginal delivery based on intrapartum sonographic findings. Design: Prospective observational study. Setting: Hangzhou, China. Population: Nulliparous women with a singleton cephalic presentation at term. Methods: Serial intrapartum ultrasonography were performed in the latent phase (T1) and every three hours after that (T2, T3 and T4). The managing clinicians performed paired digital vaginal examinations to assess labor progress. Main Outcome Measures: Delivery mode and successful internal fetal head rotation to the occiput anterior (OA) position. Results: 614 women were included, of whom 524 underwent vaginal delivery, and 90 required cesarean section. The percentage of women with fetuses in non-occiput anterior position at the latent phase was 53.9% (331 cases), as 257 women underwent spontaneous rotation to OA position before delivery, 74 were with persistent occiput posterior or transverse position. We developed a model on the basis of the maternal height and middle angel to predict the spontaneous fetal occiput rotation, with the area under the receiver operating characteristic curve (AUC) was 0.667 (95%CI 0.583-0.751). Moreover, a prediction model based on the maternal height and angle of progression to evaluate whether women underwent vaginal delivery was also developed, of which the AUC was 0.738(95% CI: 0.763-0.793). Both models showed satisfactory calibration. Conclusion: Simple models based on maternal characteristics and intrapartum ultrasound findings might provide useful information for predicting vaginal delivery and internal fetal occiput rotation.