Regulation of human gonadotropins. VI. serum follicle stimulating and luteinizing hormone determinations in children

To quantitate gonadotropins from the first year of life to maturity, serum levels of LH and FSH have been measured by radioimmunoassay in 315 children aged 6 months through 20 yr. All results were expressed in terms of 2nd- IRP-HMG, as mlU/ml followed by the standard error of the mean. Normal boys from age 1 through 10 had significantly lower levels of FSH (4.6 ±0.3) than girls (5.4±0.3), while LH levels did not differ significantly between boys and girls (2.8±0.2 vs. 2.7 ±0.2). There was a progressive increase in levels of both LH and FSH from ages 11 through 16 for boys and approximately ages 9 through 12 for girls. The rise of both hormones is earlier in girls than boys. Serum LH levels of postpubertal girls and boys were 3.5- and 2.7-fold higher than comparable levels in prepubertal age groups. FSH, compared in a similar fashion, rose 1.7-fold in girls and 1.6- fold in boys. When attempts were made to relate gonadotropin levels to pubertal development the initial appearance of the physical characteristics of puberty were not accompanied by a rise of LH or FSH in either girls or boys. Among girls, a significant rise of gonadotropins was present when pubescent girls after menarche were compared with those before menarche. Among boys, only the postpubertal group showed a significant increase over the preceding stage of development.