Ovarian Hyperstimulation Syndrome (OHSS) is one of the most dangerous complications of Assisted Reproductive Technologies (ART) cycles. The use in clinical practice of the GnRH antagonist has made it possible to perform the trigger with GnRH analogues reducing the risk of OHSS. The trigger with analogue increases the Abortion Rate (AR) and reduces the Ongoing Pregnancy Rate (OPR), because the luteal phase in these cycles is particularly deficient. To reduce this occurrence several studies have focused on the importance of support of the luteal phase. The aims of study is to evaluate OPR and AR in patients at intermediate risk of OHSS (<18 recovered oocytes) which performed GnRH trigger and rescue protocol.

Inclusion Criteria:

AMH ( antimullerian hormone) > 3.5 ng / ml, AFC (antral follicles count) > 15 follicles and if more than 18 follicles with diam. 12mm to induction

Exclusion Criteria:

high risk of OHSS ( ovarian hyperstimulation syndrome)

In HR patients (AMH> 3.5 ng / ml, AFC> 15 follicles and if more than 18 follicles with diam. 12mm to induction) the trigger was obtained with triptorelin 0.2 mg / sc. In patients considered to be at intermediate risk of OHSS a rescue protocol has been implemented (HCG 1500 IU / sc the day of the pick up + estradiol 4 mg + vaginal progesterone 400 mg daily) and fresh embryo transfer.