Gonadotropin levels at the start of ovarian stimulation predict normal fertilization after hCG re‐trigger in GnRH antagonist cycles

PURPOSE: To assess the appropriateness of human chorionic gonadotropin (hCG) re‐trigger in poor responders to gonadotropin‐releasing hormone agonist (GnRHa) trigger in controlled ovarian stimulation (COS) cycles. METHODS: The 2251 cycles in 2251 patients triggered with GnRHa for oocyte stimulation, with or without requiring hCG re‐trigger between 2013 and 2018, were retrospectively analyzed to compare gonadotropin levels at the start of COS and the rate of normal fertilization between the re‐trigger and non–re‐trigger group. Furthermore, patients in the re‐trigger group were stratified by the rate of normal fertilization (good: ≥60% or poor: <60%) to compare patient demographics, hormone profiles, and clinical outcome between the subgroups. RESULTS: In the re‐trigger group, FSH and LH levels at the start of COS were significantly lower in the good fertilization group than in the poor fertilization group (P < .01). Receiver operating characteristic curves identified cutoff values of the FSH and LH levels of 1.30 and 0.35 mIU/mL, respectively, for predicting ≥60% normal fertilization. CONCLUSION: Gonadotropin levels at the start of COS are predictors of response to GnRHa trigger and hCG re‐trigger necessity, and may serve as indicators to help clinicians appropriately choose hCG re‐trigger rather than abandoning the cycles or continuing the first oocyte aspiration attempt.