The effect of medroxyprogesterone acetate on gonadotropin secretion in girls with precocious puberty

Abstract

Plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) as detected by radioimmunoassay have been found to be present in prepubertal children and show a gradual rise until the onset of puberty. Children with idiopathic true precocious puberty have plasma gonadotropin levels which are appropriate for their advanced degree of sexual development. A potent progestational agent, 6-methyl-17-hydroxyprogesterone acetate or medroxyprogesterone has been used in the treatment of precocious puberty and will suppress its physical manifestations. In this study the effect of medroxyprogesterone on gonadotropin levels was investigated in seven girls with true precocious puberty. Plasma LH values were found to be significant lower in patients receiving this agent than in a group of normal prepubertal girls. FSH values did not differ from the control group. One patient was evaluated prior to treatment and showed decreasing levels of LH after therapy was begun. These data suggest that medroxyprogesterone may act on the pituitary-hypothalamic axis to suppress the pubertal levels of LH.

PIP: Plasma LH (luteinizing hormone) and FSH (follicle stimulating hormone) have been detected by radioimmunoassay in prepubertal children and show a gradual rise until the onset of puberty. Children with precocious puberty have plasma gonadotropin levels appropriate for their advanced sexual development. A clinical study was undertaken to determine whether Depo-Provera administered to girls in precocious puberty would have an effect on the serum gonadotropin levels. 7 girls aged 5-10 who manifested signs of prococious puberty were treated with Depo Provera and compared with 15 normal 5-10-year old girls. The Depo Provera succeeded in lowering plasma LH levels significantly below those in normal prepubertal girls. The Depo Provera had no effect on FSH levels. The mechanism whereby Depo Provera decreases LH levels is unclear. It is possible that it affects the hypothalamic releasing factor. Another explanation is that it may act as a nonspecific pituitary suppressor or may inhibit the rise in LH which seems to occur during sleep in normal pubertal children.