The plasma FSH and LH response to synthetic LH-RH in normal pre-pubertal and early pubertal girls--a re-evaluation

Abstract

A standard LH-RH test (50 microgram/m2) given iv was carried out in 65 normal girls, 42 of them pre-pubertal aged from 4 7/12 to 11 years and 23 in the early stage of puberty, aged from 9 to 12 9/12 years. The results indicate that in pre-pubertal girls the basal levels of the plasma gonadotrophins remain steady (LH 0.6 +/- 0.1 mIU/ml; FSH 0.8 +/- 0.1 mIU/ml, m +/- SD) and that there is a small but significant response of LH to LH-RH (1.6 +/- 0.2 mIU/ml). During this period the FSH response to LH-RH is very marked (8.0 +/- 1.0 mIU/ml) with a gradual, significant decrease seen towards the onset of puberty (6.5 +/- 0.9 mIU/ml, P less than 0.001). These results support earlier reports that the LH-RH test is a useful tool to evaluate the secretion of pituitary LH and FSH in early childhood.