High serum concentrations of dimeric inhibins A and B in normal newborn girls

Abstract

Objective: To establish the serum pattern of dimeric inhibins in normal girls during the newborn period and to examine its relationship with the postnatal gonadotropic surge. Design: Retrospective study. Setting: Division of endocrinology of a children’s hospital. Patient(s): Thirty-one girls 4 to 65 days of age. Main Outcome Measure(s): Serum levels of FSH, LH, and inhibin A and B. Result(s): High serum concentrations of both dimeric inhibins were detected during the first weeks of life. Concentrations tended to decrease through the second month of age. Inhibin A and B concentrations positively correlated with age only during the first 2 weeks of life ( r = .57, P<.05 and r = .70, P<.01, respectively). Inhibin A and B were positively and significantly correlated with LH ( r = .57, P<.05 and r = .52, P<.05, respectively) and with each other ( r = .68, P<.0001). No correlation was found between dimeric inhibins and FSH. Conclusion(s): The high inhibin concentrations observed in newborn girls, which indicate advanced follicular development and granulosa cell differentiation, may be useful markers for congenital gonadal disorders.