FSH in GnRH-AntagoniST Controlled Ovarian Hyperstimulation Cycles (FAST)

Inclusion Criteria: * Age: 18-38 years old; * BMI: 18-28 kg/m2; * Less than 3 previously completed IVF cycles; * Basal FSH \<10 IU/L and E2 \<80 pg/ml; * TSH \< 2.5 mIU/L * \>10 and \<30 antral follicles 2-10 mm in size for both ovaries combined * AMH: \>1 ng/ml (7.15 pmol/l) and \<5.6 ng/ml (40.0 pmol/l) * Presence and adequate visualization of both ovaries; * Within 12 months of the beginning of the study, uterine cavity consistent with expected normal function as assessed through transvaginal ultrasound, hysterosalpingogram, sonohysterogram or hysteroscopic examination; Exclusion Criteria: * Primary ovarian failure or women known as poor responders; * PCO and PCOS; * Severe OHSS in a previous COH cycle; * Uterine malformation that may impair the possibility to get pregnant; * Ovarian cysts \>10 mm; * Hydrosalpinx that have not been surgically removed or ligated; * Endometriosis stage 3 or 4; * Oocyte donation; * Severe male factor; * Pathologies associated with any contraindication of being pregnant; * History of recurrent miscarriage (more than 3 previous miscarriages); * Hypersensitivity to the study medication; * Abnormal bleeding of undetermined origin; * Uncontrolled thyroid or adrenal dysfunction; * Neoplasias; * Severe impairment of renal and/or hepatic function.