Premature ovarian insufficiency (POI) is a clinical syndrome defined by loss of ovarian activity before the age of 40 years. The POI guideline development group of ESHRE recommends the following diagnostic criteria: oligo/ amenorrhea for at least 4 months and an elevated follicle stimulating hormone (FSH) level >25 mIU/mL on two occasion >4 weeks apart. Some clinicians and researchers proposed that POI was a progressive disease and there were three stages of POI: occult POI, biochemical POI, overt POI. However, there is lack of reliable indicators to assess the different stages of POI. The present study is to explore the change of menstruation condition, basal follicle-stimulating hormone, anti-müllerian hormone and antral follicle count during the development of POI, and whether those marks can assess the different stages of POI.

Inclusion Criteria:

• Serum FSH levels ≥10mIU/ml/ serum AMH levels ≤1.0pg/ml/ AFC ≤5, on at least two occasion >4 weeks apart

Exclusion Criteria:

• Polycystic Ovarian Syndrome
• other causes of amenorrhea

patients of occult premature ovarian insufficiency