Background Despite the existence of numerous published models predicting the risk of caesarean delivery in women undergoing induction of labour (IOL), validated models are scarce. Objectives To systematically review and externally assess the predictive capacity of caesarean delivery risk models in women undergoing IOL. Search strategy Studies published up to 15 January 2021 were identified through PubMed, CINAHL, Scopus and ClinicalTrials.gov, without temporal or language restrictions. Selection criteria Studies describing the derivation of new models for predicting the risk of caesarean delivery in labour induction. Data collection and analysis Three authors independently screened the articles and assessed the risk of bias (ROB) according to the prediction model risk of bias assessment tool (PROBAST). External validation was performed in a prospective cohort of 468 pregnancies undergoing IOL from February 2019 to August 2020. The predictive capacity of the models was assessed by creating areas under the receiver operating characteristic curve (AUCs), calibration plots and decision curve analysis (DCA). Main results Fifteen studies met the eligibility criteria; 12 predictive models were validated. The quality of most of the included studies was not adequate. The AUC of the models varied from 0.520 to 0.773. The three models with the best discriminative capacity were those of Levine et al. (AUC 0.773, 95% CI 0.720–0.827), Hernández et al. (AUC 0.762, 95% CI 0.715–0.809) and Rossi et al. (AUC 0.752, 95% CI 0.707–0.797). Conclusions Predictive capacity and methodological quality were limited; therefore, we cannot currently recommend the use of any of the models for decision making in clinical practice. Tweetable abstract Predictive models that predict the risk of cesarean section in labor inductions are currently not applicable.

Background: Vaginal dinoprostone (PGE2) is currently used as the prostaglandin of choice in many obstetric units. However, few studies have evaluated its safety, especially in women who previously had a cesarean section. Objective: To evaluate the efficacy and safety of PGE2 in pregnant women who are undergoing induction of labor (IOL), and who have had a previous cesarean section. Materials and Methods: A prospective observational study was conducted in La Mancha Centro Hospital in Alcázar de San Juan, Spain, from 1 February 2019 to 30 August 2020. Obstetric and neonatal outcomes, following IOL with PGE2, in 47 pregnant women who wanted a trial of labor after cesarean (TOLAC), and 377 pregnant women without a history of cesarean section, were analyzed. The outcomes were analyzed by bivariate and multivariate analyses using binary and multiple linear regression. Results: A total of 424 women were included in this study. The percentage of cesarean sections in the TOLAC group was 44.7% (21), compared with 31.6% (119) in the group without a history of cesarean section (adjusted odds ratio: 1.4; 95% CI: 0.68–2.86). In the multivariate analysis, no statistically significant differences were observed between both groups for obstetric and neonatal outcomes (p > 0.05). However, two uterine ruptures (4.3%) occurred in the group of patients with a history of cesarean section who underwent IOL with PGE2. Conclusions: The induction of labor with vaginal dinoprostone (PGE2), in patients with a previous history of cesarean section, was not associated with worse obstetric or neonatal outcomes compared with the group of patients without a history of cesarean section in our study sample. However, further research is needed regarding this IOL method, and it should be used with caution in this population group.

Purpose: To evaluate the effect and safety of vaginal dinoprostone in pregnant women with PROM who undergo induction of labor (IoL). Materials and Methods: Prospective observational study conducted at La Mancha Centro hospital from 1 February 2019, to 30 August 2020. Obstetric and neonatal variables of 94 pregnant women with PROM who underwent IoL with vaginal dinoprostone were analyzed, and the results were compared with 330 patients without PROM who also underwent IoL. Bivariate and multivariate analyses were performed using binary and multiple linear regression. Results: A total of 424 women were included in this study. A greater response to cervical ripening (Bishop score > 6) with PGE2 was observed in the PROM group (odds ratio (OR) 2.73, 95% confidence interval (CI) 1.50–4.99, p = 0.001), as well as a shorter total duration of IoL (mean difference (MD) 2823.37 min (min), 95% CI 1257.30–4389.43, p < 0.001). Cesarean sections were performed in 28.7% (n = 27) of patients in the PROM group vs. 34.2% (n = 113) of patients in the non-PROM group, with no significant differences (OR 0.87%, 95% CI 0.47–1.60, p = 0.652). There were no significant differences in changes in the cardiotocographic record (CTG), postpartum hemorrhage (PPH), uterine rupture, or adverse neonatal outcomes between the two groups. Conclusions: The use of vaginal dinoprostone in pregnant women undergoing IoL with PROM is safe for the mother and the fetus, shortens the total delivery time, and does not increase the risk of cesarean section compared with pregnant women undergoing IoL without PROM.