Development of nomogram to predict the probability of blastocyst formation on day 5: a retrospective study

Abstract

Abstract Background Blastocyst transfer may cause cycle cancellation due to no blastocyst has developed. Could we develop a model for predicting probability of blastocyst formation on Day 5?Methods The model was developed base on 4327 fresh in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles. Univariate logistic regression analysis and multivariate logistic regression analysis were conduct to investigate the relationship between patient and cycle characteristics and the formation of usable blastocysts on Day 5. And the nomogram was developed based on variables selected from multivariate logistic regression analysis. Discrimination and calibration of the model was evaluated by area under the curve (AUC) of the receiver operating characteristic (ROC) curve and calibration curve.Results Female age, type of fertilization, fertilization rate, cleavage rate, number of Day 3 embryo extended culture to blastocyst stage, high-quality rate of Day 3 embryos extended culture to blastocyst stage, were predictors of usable blastocysts formation on Day 5. Results showed AUC in the training cohort was 0.874 (95% CI 0.862–0.887) and AUC in validation cohort was 0.886 (95% CI 0.867–0.905), indicating the good discrimination ability of the model. And the calibration curves in training and validation cohorts were both close to the ideal diagonal line, reflecting good accuracy of the model.Conclusion This model provides an intuitive and simple tool for predicting the probability of usable blastocysts formation on Day 5, and it may be helpful to reduce the cancellation rate of blastocyst transfer.