Clinical and endocrine response to the withdrawal of gonadotropin-releasing hormone agonists during prolonged coasting.

Objective To compare the clinical and endocrine response of cycles in which GnRH agonists (GnRH-a) were stopped with cycles in which the agonists were continued during coasting. Design Retrospective study of stimulation cycles using flare and luteal agonist protocols. Setting Academic. Patient(s) Fifty-nine IVF and intracytoplasmic sperm injection (ICSI) treatment cycles in 57 women, coasted for 3 or more days. Intervention(s) The GnRH-a were withdrawn when E 2 levels continued to increase during coasting. Main Outcome Measure(s) Hormone concentrations, ultrasound findings, cycle cancellation, ovarian hyperstimulation syndrome (OHSS), oocyte retrieval, fertilization, embryo transfer, and clinical pregnancy rates (PR). Result(s) In the GnRH-a withdrawn group E 2 levels decreased by 63% (18,043–6,656 pmol/L) without cycle cancellations or cases of severe OHSS. In the agonist continuation group, the spontaneous E 2 decrease was 29% (14,205–10,132 pmol/L) with cycle cancellation and severe OHSS rates of 9.5% (4/42) and 4.8% (2/42), respectively. Oocyte retrieval, fertilization, embryo transfer, and clinical PRs were not compromised by stopping the agonists. Variations in the dynamic responses of FSH, LH, anti-Mullerian hormone, P, and androstenedione (A) levels in these cycles are described. Conclusion(s) Withdrawal of GnRH-a during coasting interrupted increasing E 2 levels, prevented cycle cancellation, and mitigated the risk of OHSS in this high risk group without compromising oocyte retrieval, fertilization, embryo transfer, or PRs.