Lower levels of inhibin A and pro-alphaC during the luteal phase after triggering oocyte maturation with a gonadotropin-releasing hormone agonist versus human chorionic gonadotropin.

OBJECTIVE To investigate the effect of triggering oocyte maturation with GnRH agonist on corpus luteum function by measuring luteal phase levels of inhibin A and pro-alphaC. DESIGN Prospective randomized trial. SETTING In vitro fertilization (IVF) program at a university hospital. PATIENT(S) Infertile women undergoing IVF-ET treatment. INTERVENTION(S) Controlled ovarian hyperstimulation with FSH and GnRH antagonist, triggering of final oocyte maturation with either hCG (n = 8) or GnRH agonist (n = 8), IVF-ET, and collection of blood samples every 2-3 days during the luteal phase. MEASUREMENTS AND MAIN RESULTS Luteal phase serum levels of inhibin A and pro-alphaC, P, and E(2). RESULT(S) Levels of inhibin A, pro-alphaC, estrogen, and P were significantly lower from day 4 to day 14 after triggering final oocyte maturation by GnRH agonist compared with hCG. Maximal luteal serum inhibin A and pro-alphaC levels were 91.5 +/- 23.6 and 184.1 +/- 23.5 pg/mL in the GnRH agonist-treated women compared with 464.7 +/- 209.1 and 7,351.6 +/- 934.3 pg/mL in women treated with hCG. CONCLUSION(S) Triggering final oocyte maturation with GnRH agonist instead of hCG in IVF cycles dramatically decreases luteal levels of inhibins, reflecting significant inhibition of the corpus luteum function. This effect may explain, at least in part, the mechanism of ovarian hyperstimulation syndrome prevention by the use of GnRH agonist.