Predictors of success during the coasting period in high-responder patients undergoing controlled ovarian stimulation for assisted conception

Objective To determine the prognostic factors analyzed during the coasting period that can be used to predict outcomes of IVF cycles. Design Retrospective review of data from a single center. Setting Referral private IVF center. Patient(s) Three hundred forty-six patients who were coasted for the prevention of ovarian hyperstimulation syndrome (OHSS) and 262 patients who were not coasted but having excessive E₂ levels during controlled ovarian hyperstimulation for assisted conception. Intervention(s) Controlled ovarian hyperstimulation, oocyte retrieval, intracytoplasmic sperm injection, and embryo transfer. Main outcome measure(s) Number of total oocytes retrieved, oocyte maturity, fertilization, implantation and pregnancy rates (IR and PR, respectively), and incidence of severe OHSS. Result(s) No difference was found between early onset coasted patients, late onset coasted patients, and uncoasted patients in terms of fertilization rates, IR, PR, and incidence of severe OHSS. Fertilization and PR did not correlate significantly with decreases in E ₂ level during the coasting period. Implantation rates and PR in patients who were coasted ≥4 days were significantly reduced compared with patients who were coasted for 1-3 days. In logistic regression model, the decrease in PR with prolonged coasting was found to be significant; however, there was no correlation between decreased PR and the decrease in E₂ levels during the coasting period. Conclusion(s) Coasting can be applied safely to controlled hyperstimulation cycles without compromising the outcome. The duration of coasting seems to be a prognostic factor for the outcome of IVF. The criteria for initiation of coasting should be based on clinical experience and assessment of the patient.