Adult polycystic ovary syndrome begins in childhood.

Polycystic ovary syndrome (PCOS) frequently presents during adolescence and is the commonest cause of menstrual irregularity and hirsutism. The characteristic endocrine abnormalities include hypersecretion of androgens and LH. Metabolic dysfunction is also a feature of many young women with PCOS. Hyperinsulinaemia and insulin resistance, which can be regarded as an exaggeration of the normal metabolic changes that occur during puberty, are further amplified by obesity. The aetiology of PCOS is uncertain but there is evidence for a primary abnormality of ovarian androgen production which is manifest at puberty but may have its origins in childhood or even during fetal development.