Adrenarche begins before the rise in gonadotropin secretion. The rising levels of plasma gonadotropins stimulate the ovary to produce increasing amounts of estradiol. The maturation of the ovary at adolescence correlates well with estradiol secretion and the stages of puberty. During puberty, plasma estradiol levels fluctuate widely, probably reflecting successive waves of follicular development that fail to reach the ovulatory stage. Plasma testosterone levels also increase at puberty although not as markedly as in males.
Plasma progesterone remains at low levels even if secondary sexual characteristics have appeared.
A rise in progesterone after menarche is, in general, indicative that ovulation has occured. The first ovulation does not take place until 6-9 months after menarche because the positive feedback mechanism of estrogen is not developed. As puberty progresses, spermatogenesis is initiated and then sustained by FSH and by testosterone produced by the Leydig cells under LH control. A significant increase of plasma testosterone is found only between Tanner pubertal stages P3 and P4. There is accumulating evidence that GH plays a role in pubertal development.