Gonadotropins and sex hormones in healthy Chinese infants.

This study was conducted to investigate the infantile changing regularity of gonadotropins and sex hormones. Serum samples were obtained from 416 healthy infants (male: 215; females: 201). In male infants, peaks in serum gonadotropins and testosterone concentrations were observed at 2-4 months. In female infants, serum FSH concentrations reached peak at 2-3 months. Before 6 months, serum testosterone and LH concentrations were higher in male, while FSH was on the contrary. Peaks in serum gonadotropins and sex hormones concentrations are reached and sexual dimorphism appears in the early infancy. Defining the range of mean values and the trends for infantile gonadotropins and sex hormones could be helpful for clinical evaluation.