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INTERVENTION(S): The GnRH-a were withdrawn when E(2) levels continued to increase during coasting.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RESULT(S): In the GnRH-a withdrawn group E(2) levels decreased by 63% (18,043-6,656 pmol/L) without cycle cancellations or cases of severe OHSS.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-Müllerian 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.