[The ovary at puberty]

Our investigation includes two groups of subjects in which the relationships between ovarian growth, steroidogenesis and gonadotropin secretion were studied. The first group consists of premenarchal girls studied in a cross-sectional program; the second group includes girls after menarche with irregular cycles who were investigated with a long term follow up. In the first group an increase in ovarian volume and in the number of developing follicles were seen with increasing chronological age and pubertal stages. With advancing pubertal development, a progressive increase of LH pulse frequency and amplitude can be observed. These variables appear strongly linked to the ovarian morphological and functional development as the significant correlation between LH mean levels and pulsatile characteristics on the one hand, and ovarian volume and steroid production on the other hand demonstrate. In the maturational stage just before menarche, the ovaries may show increased volume and a very dishomogeneous structure; ovarian steroidogenesis may be often mainly directed towards the androgen synthesis. After menarche ovarian volume and structure continue to change and normal or enlarged ovaries, with homogeneous, multifollicular or polycystic structure can be frequently observed. However normal and homogeneous ovaries prevail in adolescents with regular and ovulatory cycles, while enlarged and dishomogeneous ovaries prevail in irregular anovulatory cycles. A trend towards normal adult ovarian morphology and structure is present in ovulatory subjects with normal gonadotropin pulsatile release and steroid synthesis. On the other hand, deranged gonadotropin profiles imply irregular cycles anovolation, hyperandrogenemia and enlarged polycystic ovaries during adolescence.(ABSTRACT TRUNCATED AT 250 WORDS)