Serum FSH Monitoring for Identification of an Optimal Range During Ovarian Stimulation

Women between 18 and 39 years old, with regular 21 - 35 days cycles, BMI between 19 - 30 kg/m2, serum AMH level between 1.5 to 3 ng/ml, a total antral follicle count between 10 to 24, endogenous early follicular phase serum FSH level \<10 IU/L, normal glomerular filtration rate who is planned to undergo ovarian stimulation in a Gonadotropin hormone-releasing hormone (GnRH) antagonist protocol can be included. Exclusion will be for women with hypogonadotropic hypogonadism, history of ovarian surgery, permanent ovarian cysts of any form, older than 39 years, abnormal thyroid function (TSH level outside the normal range), renal disease, elevated prolactin levels. intake of oral contraceptives 3 months before stimulation start and estradiol pretreatment will be excluded.