Most women of reproductive age have numerous eggs developing in their ovaries at any given time. Eggs grow in small fluid-filled pockets called follicles. In a natural ovulatory cycle, the body produces a female hormone in just the right amount to stimulate one single egg to mature.
Adequate ovarian response to gonadotrophin stimulation leading to the development of several eggs is a prerequisite for successful in vitro fertilization (IVF) treatment. While exaggerated ovarian response can be complicated by ovarian hyperstimulation syndrome (OHSS), poor response may result in cycle cancellation or decreased pregnancy rate. Identification of patients at risk of extremes of ovarian response prior to controlled ovarian hyperstimulation (COH) is of paramount importance in selecting the best treatment protocol and the starting dose of gonadotrophins.
A search for a marker that better reflect the quantity and quality of growing follicles has led to more recent emphasis on anti-Müllerian hormone (AMH) and antral follicle count (AFC) because of their advantages as compared with other predictors such as the hormones measured in the blood follicle stimulating hormone (FSH), oestradiol (E2), inhibin B and ovarian volume.
Anti-Müllerian hormone can be measured at any time throughout the menstrual cycle, making it a versatile and friendly test. Antral follicle count can be performed by ultrasound scan only during the first few days of the menstrual cycle (day 2-4). The inter-cycles variability of AFC is a limitation of its overall predictive capacity. Although the evidence suggests that AMH is superior to AFC in predicting excessive ovarian response to stimulation, both markers were found to be equally effective in prediction of poor response.