Context
Limited data exist regarding whether the endocrine response to the gonadotropin-releasing hormone receptor agonist (GnRHa) triptorelin differs in women with polycystic ovary syndrome (PCOS) compared with healthy women or those with hypothalamic amenorrhea (HA).

Objective
We compared the gonadotropin response to triptorelin in healthy women, women with PCOS, or those with HA without ovarian stimulation, and in women with or without polycystic ovaries undergoing oocyte donation cycles after ovarian stimulation.

Methods
The change in serum gonadotropin levels was determined in (1) a prospective single-blinded placebo-controlled study to determine the endocrine profile of triptorelin (0.2 mg) or saline-placebo in healthy women, women with PCOS, and those with HA, without ovarian stimulation; and (2) a retrospective analysis from a dose-finding randomized controlled trial of triptorelin (0.2-0.4 mg) in oocyte donation cycles after ovarian stimulation.

Results
In Study 1, triptorelin induced an increase in serum luteinizing hormone (LH) of similar amplitude in all women (mean peak LH: healthy, 52.3; PCOS, 46.2; HA, 41.3 IU/L). The AUC of change in serum follicle-stimulating hormone (FSH) was attenuated in women with PCOS compared with healthy women and women with HA (median AUC of change in serum FSH: PCOS, 127.2; healthy, 253.8; HA, 326.7 IU.h/L; P = 0.0005). In Study 2, FSH levels 4 hours after triptorelin were reduced in women with at least one polycystic morphology ovary (n = 60) vs normal morphology ovaries (n = 91) (34.0 vs 42.3 IU/L; P = 0.0003). Serum anti-Müllerian hormone (AMH) was negatively associated with the increase in FSH after triptorelin, both with and without ovarian stimulation.

Conclusion
FSH response to triptorelin was attenuated in women with polycystic ovaries, both with and without ovarian stimulation, and was negatively related to AMH levels.