Risk charts to identify low and excessive responders among first-cycle IVF/ICSI standard patients

Ovarian stimulation carries a risk of either low or excessive ovarian response. The aim was to develop prognostic models for identification of standard (ovulatory and normal basal FSH) patients’ risks of low and excessive response to conventional stimulation for IVF/intracytoplasmic sperm injection. Prospectively collected data on 276 first-cycle patients treated with 150 IU recombinant FSH (rFSH)/day in a long agonist protocol were analysed. Logistic regression analysis was applied to the outcome variables:low (seven or less follicles) and excessive (20 or more follicles) response. Variables were woman’s age, menstrual cycle length, weight or body mass index, ovarian volume, antral follicle count (AFC) and basal FSH. The predictive performance of the models was evaluated from the prediction error (Brier score, %) where zero corresponds to a perfect prediction. Model stability was assessed using 1000 bootstrap cross-validation steps. The best prognostic model to predict low response included AFC and age (Brier score 7.94) and the best model to predict excessive response included AFC and cycle length (Brier score 15.82). Charts were developed to identify risks of low and excessive ovarian response. They can be used for evidence-based risk assessment before ovarian stimulation and may assist clinicians in individual dosage of their patients.