Endocrine and ovarian parameters at various frequencies of ovulation in adolescents.

We assessed ovarian and endocrine function in 86 adolescents over a six month period. Postmenstrual estrone (E1) and estradiol-17 beta (E2) levels, premenstrual FSH levels and pre- and postmenstrual LH, testosterone (T) and androstenedione (A) levels decreased as the frequency of ovulation increased, while premenstrual E2, progesterone (P) and 17 alpha-hydroxyprogesterone levels increased. Both right and left ovarian volume and the per cent of multifollicular ovaries decreased with an increase in the frequency of ovulation. In the premenstrual phase P values correlated significantly with frequency of ovulation for FSH (r = -0.43: P less than 0.001), LH (r = -0.36: P less than 0.01), T (r = -0.31: P less than 0.05) and A (r = -0.26: P less than 0.05). Our data suggest that in the postmenarcheal period the progressive loss of immature endocrine and ovarian characteristics (high LH, FSH, and androgen levels and enlarged, multifollicular ovaries) is linked to an increasing number of ovulations. Progesterone plays a major role in the development of cyclic function characteristic of adult maturity.