Time Course of the Serum Gonadotropin Surge, Inhibins, and Anti-Mullerian Hormone in Normal Newborn Males during the First Month of Life

BERGADA IGNACIO; MILANI CARLOS; BEDECARRAS PATRICIA; ANDREONE LUZ; ROPELATO MARIA GABRIELA; GOTTLIEB SILVIA; BERGADA CESAR; CAMPO STELLA; REY RODOLFO A

JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM

Año: 2006 vol. 91 p. 4092 - 4098

0021-972X

Context. Newborns with ambiguous genitalia or males with non palpable gonads usually require an early assessment of the presence and functional state of testicular tissue. Objective. To characterize the precise ontogeny of the serum patterns of gonadotropins, testosterone, AMH and inhibins in normal newborn boys. Design. Cross-sectional and longitudinal study. Subjects. Serum samples were obtained in 57 boys and 13 girls at day 2 of life. A second sample was obtained at days 7, 10, 15, 20 and 30 (boys), and at day 30 (girls). Main Outcome Measures. Serum levels of gonadotropins, testosterone, AMH and inhibins. Results. In males, LH and FSH were undetectable or very low at D2. By D7, LH increased to 3.94 ± 1.06 IU/L (mean ± SEM) and FSH to 2.04 ± 0.56 IU/L. LH/FSH ratio was 0.40 ± 0.11 (D2) and 2.02 ± 0.20 (D30). AMH rose from 451.5 ± 48.8 pmol/L (D2) to 699.0 ± 73.7 pmol/L (D30), and inhibin B from 214.4 ± 85.9 ng/L (D2) to 360.5 ± 27.9 ng/L (D30). Pro-aC remained stable during the first month of life. Testosterone levels were 72.5 ± 16.1 ng/dL (D2), 81.7 ± 8.0 ng/dL (D20) and 210.3 ± 45.8 ng/dL (D30). A sexual dimorphism was observed in AMH and inhibin B (lower in girls at D2 and D30), in LH/FSH ratio (lower in girls at D30) and in testosterone (lower in girls at D30). Conclusions. Sertoli cell markers AMH and inhibin B are the earliest useful markers indicating the existence of normal testicular tissue.