COASTING DOES NOT ADVERSELY AFFECT CYCLE OUTCOME IN A SUBSET OF HIGHLY RESPONSIVE IN-VITRO FERTILIZATION PATIENTS

Objective: To study the effect of postponing hCG administration while continuing daily GnRH agonist therapy (''coasting'') on highly respons ive patients undergoing NF-ET. Design: Retrospective analysis. Setting : University-affiliated Center for Fertility and Reproductive Medicine .Patient(s): Patients undergoing IVF-ET from March 1995 to March 1997. Intervention(s): Three groups of NF-ET patients were compared to expl ore the effect of coasting on cycle outcome: a group of highly respons ive coasted patients, a group of equally responsive noncoasted patient s, and an age-matched normally responsive control group. Two groups of coasted patients were also compared to assess the effect of E-2 level s at the time that they met the follicular criteria for hCG administra tion. Last, the effect of varying coast duration was examined by regre ssion analysis. Main Outcome Measure(s): Patient characteristics, outc ome parameters, and incidence of ovarian hyperstimulation syndrome (OH SS). Result(s): Coasting had no detrimental effect on cycle outcome in the subset studied. Regression analysis, however, suggests an inverse relationship between coast duration and the number of mature oocytes retrieved as well as the clinical pregnancy rate. Conclusion(s): Coast ing in the studied subset of IVF patients did not adversely affect cyc le outcome parameters or the incidence of OHSS, but prolonged coasting intervals may impair IVF cycle outcome. (C) 1998 by American Society for Reproductive Medicine.