Fig. 2: Kaplan–Meier graph of time to cumulative live births by randomized group (intention-to-treat population).

HR, hazard ratio. Shaded areas indicate 95% confidence intervals (CI). Median time to live birth in the blastocyst group was 344 days (95% CI, 334–353 days); median time to live birth in the cleavage-stage group was 373 days (95% CI, 353–416 days). Hazard ratio and the associated 95% CIs were estimated by using a Cox proportional hazards model. Source data are provided as a Source Data file.