Development of a simplified shoulder dystocia risk index: a retrospective single-center study
DOI:
https://doi.org/10.37800/RM.1.2026.609Keywords:
shoulder dystocia (SD), pregnancy, obstetric complicationsAbstract
Relevance: Shoulder dystocia (SD) is a rare but clinically significant complication of vaginal delivery, associated with brachial plexus injury in newborns and obstetric complications in the mother.
The study aimed to develop and internally validate a simplified SD risk index for use in the clinical practice of maternity hospitals in Kazakhstan.
Materials and methods. A retrospective single-center cohort study was conducted, including all vaginal births at ≥ 37 weeks of gestation (01.2020–12.2024; n = 15,285). The outcome was SD, defined as the need to perform ≥ 1 additional maneuver after delivery of the fetal head. The model included four clinically justified predictors: estimated fetal weight (EFW) ≥ 4000 g, body mass index (BMI) ≥ 30 kg/m², diabetes (gestational/pre‑gestational), and induction/augmentation of labor. A Firth logistic regression model was built and subsequently converted into a point-based scoring system.
Results. The frequency of SD was 0.098% (15/15,285). The final predictors and assigned points were: EFW ≥ 4000 g – 3; BMI ≥ 30 kg/m² – 2; diabetes – 2; induction/augmentation – 1. The total score ranged from 0 to 8. The model demonstrated good discrimination (AUC-ROC = 0.82; 95% CI 0.75–0.89) and acceptable calibration (Brier score = 0.00095). At a threshold of ≥ 3 points, sensitivity was approximately 75% and specificity approximately 80%, with a very high negative predictive value.
Conclusion. The simplified SD risk index, based on four readily available predictors, demonstrates good predictive performance and can be used for risk stratification, planning obstetric team preparedness, and rational resource allocation in maternity hospitals in Kazakhstan. External multicenter validation of the model is required.
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