Introduction
The polycystic ovary syndrome (PCOS) is a common disorder characterized by chronic anovulation and hyperandrogenism, and frequently associated with insulin resistance and type 2 diabetes mellitus. Signs and symptoms of PCOS usually develop during, or soon after, puberty (Ehrmann et al. 1995, Apter 1998), and several features of the PCOS can be recognized in girls with premature pubarche and adolescents with hyperandrogenism (Ibañez et al. 1993).
In the last decade, the concept of PCOS has evolved from being mostly a reproductive disorder to a metabolic disorder. Nowadays, PCOS is described as a heterogeneous disorder presenting with a constellation of different manifestations throughout the life of women (Ibañez et al. 1998c). The familial clustering of women with PCOS suggests that heredity is involved in the pathogenesis of the syndrome, but the underlying mechanisms are unknown.
Polycystic ovary syndrome is the first component of the metabolic syndrome to be detected in many women (Dunaif 1997). The early identification of the syndrome will have important implications in the prevention and treatment of affected women, especially since progression of the full-blown syndrome might be ameliorated and prevent from the lifelong sequelae of PCOS. This chapter reviews the origin of PCOS during childhood and adolescence.
Physiology of puberty in the female
Puberty is the transition period from the sexually immature state to becoming capable of reproducing, which is marked by the appearance of secondary sexual characteristics and acceleration in growth. Two physiological processes, gonadarche and adrenarche, drive the transition to puberty.