Table 2.

Changes in the plasma kisspeptin levels in each phase of assisted reproductive technology (ART)

	Phase I	Phase II	Phase III	Phase IV	P‐value	P‐value
						Phase I vs phase III	Phase I vs phase IV
Kisspeptin level (pg/mL) (mean ± SD)	5.62 ± 2.29	6.85 ± 3.24	7.75 ± 2.10	7.21 ± 2.83	.008	.003	.002

Values are the mean ± SD of the plasma kisspeptin levels in each phase of ART. Phases III and IV were significantly higher than phase I. Phase I, the beginning of stimulation (after menstruation); Phase II, the day the schedule for the ovum pick‐up (OPU) was decided (2‐6 days before the OPU); Phase III, the day of the OPU (35 h after the 10 000 IU human chorionic gonadotrophin injection); Phase IV, the day of the embryo transfer (2‐6 days after the OPU).