Table 1.

Pharmaceutical options for the triggering of final oocyte maturation in ART: summary and recommendations.

Subject	Current knowledge	Recommendations
GnRHa trigger and oocyte/embryo quality: the oocyte donor model	No significant differences in the number of retrieved oocytes (total and mature), fertilization rates, embryo quality, and pregnancy rates in recipients	First line treatment in egg donors
	Substantial decrease in the treatment burden of the egg donor
The luteal phase after GnRH-agonist triggering of ovulation	GnRH-agonist triggering is associated with luteal phase insufficiency despite the standard supplementation with vaginal progesterone and estradiol	Luteal phase rescue protocols:
		1500 IU hCG, 35 h after GnRHa trigger∗
		IM prog + E2 patches adjusted according to serum levels∗
		Repeated bolus of 500 IU hCG
		Repeated bolus of rec-LH
		Freeze-all strategy
OHSS after GnRHa triggering	OHSS cases described in extremely high responders who received the 1500 IU hCG rescue protocol	GnRHa trigger and modified luteal support with one bolus of hCG should be used with caution in extremely high responder patients
		Patients with a higher OHSS risk (>25 follicles) currently benefit from a freeze-all strategy
	Two OHSS cases reported after GnRHa triggering without any type of luteal phase support	Rare event of unknown etiology
		GnRH, FSH, or LH receptor gene mutations presumably involved
Failure of GnRHa triggering of final follicular maturation	A recent large database analysis showed that the incidence of EFS seems to be similar regardless of whether GnRHa (3.5%) or hCG (3.1%) triggering is used for final oocyte maturation	Certain forms of pituitary dysfunctions might be responsible for these outcomes in GnRHa triggered cycles
		Most cases of EFS are related to human error, and, thus, a meticulous counseling and instruction of the patient prior to oocyte retrieval is of outmost importance
Kisspeptins (KP) for final follicular maturation in the horizon	KP are potent stimulators of the hypothalamic-pituitary-gonadal axis	Much remains to be learned about the role of KP in the control of ovulation
	KP signals directly to the GnRH neurons, which in turn stimulates the secretion of both LH and FSH from the anterior pituitary that is able to induce a physiological final follicular maturation	The promising results of a preliminary study need to be further explored in large clinical trials

*Supported by large RCTs.