ABSTRACT
An increased serum FSH level on day 3 of the menstrual cycle is a biomarker for ovarian reserve decline and is believed to indicate a reduced reproductive potential35. Women with elevated FSH levels may require consistently more gonadotropin stimulation than women with a low range of FSH levels36. It has been known that women with higher basal FSH levels have a poor outcome compared with those with a normal range of FSH levels37,38. As FSH levels rise, there is a progressive decline in the pregnancy rate, suggesting that basal FSH is a better predictor than age with regard to pregnancy and cancellation rates39. Therefore, basal serum FSH level is the most widely used test of ovarian reserve and is strongly associated with poor ovarian response to gonadotropin stimulation40. However, there remains a group of young women with an apparently normal basal FSH level and ovarian reserve who do not respond well. In this case, the small antral follicle counting may be a better prognostic indicator of poor response before controlled ovarian stimulation for IVF treatment41. Another ultrasound marker of ovarian response may be ovarian volume42.
