Hormonal pattern of adolescent menstrual cycles

Serum FSH, LH, PRL, estradiol, pregnenolone, progesterone, 17-hydroxyprogesterone, androstenedione, testosterone, 5 alpha-dihydrotestosterone, and androsterone were measured radioimmunologically in 20 normal girls aged 13-17 yr. Samples were taken every day or every second day during one menstrual cycle. The cycles recorded could be divided into three groups. The first and oldest group consisted of 10 girls with a mean gynecological age (years since menarche) of 2.9 yr. The luteal phase was at least 11 days and the progesterone concentration was at least 5 ng/ml. The testosterone rise (mean, 55%) on the day of LH surge correlated well with the simultaneous progesterone rise (mean, 270%) and the following luteal progesterone secretion. A negative correlation was seen between the FSH concentration on days 3-4 of the cycle and the length of the follicular phase. The second group consisted of 4 girls who had a mean gynecological age of 1.5 yr. The luteal phase was of 4- to 8-day duration and the progesterone secretion was lower than in group I. The follicular phase testosterone concentration was lower in group II as compared to group I. No "periovulatory" testosterone increases were seen, although every cycle displayed an LH and FSH peak. The third group consisted of 6 girls with a mean gynecological age of 1.1 yr. These cycles were anovulatory, as the serum progesterone concentration never exceeded 1.0 ng/ml. In two cycles, signs of follicular maturation were seen. In the four others, the androgen levels tended to be elevated. In two cases, the testosterone and androstenedione concentrations were 2-4 times elevated from the beginning of these two cycles. Thus, the hormonal pattern of adolescent menstrual cycles is far from uniform. It is very likely that in addition to gonadotropins, estradiol and progesterone, androgens may also have a role in the development and maintenance of normal menstrual function in the female.