Development and validation of nomograms for predicting preterm delivery

OBJECTIVE: The objective of the study was to develop a statistical model for predicting risk of preterm delivery after in utero transfer for threatened preterm delivery in tertiary care centers. STUDY DESIGN: This study was an observational study including a total of 906 patients transferred for threatened preterm delivery at Paule-de-Viguier and Croix-Rousse University Hospitals. Clinical and sonographic data from 1 series were used to construct logistic regression models for predicting preterm delivery and were validated on an independent series. An Internet-based tool was developed to facilitate the use of the nomograms. RESULTS: Based on multivariate analyses, 2 nomograms were built: 1 to predict delivery within 48 hours after transfer and 1 to predict delivery before 32 weeks. Discrimination and calibration of the predictive models were good when applied to the validation set (concordance index 0.73 and 0.72, respectively). CONCLUSION: We developed and validated nomograms to predict the individual probability of preterm birth after transfer for threatened preterm delivery.