Serum inhibin A and inhibin B in healthy prepubertal, pubertal, and adolescent girls and adult women: relation to age, stage of puberty, menstrual cycle, follicle-stimulating hormone, luteinizing hormone, and estradiol levels

Biochemical assessment of gonadal function during maturation in girls and in adult women can be troublesome. With the recent advent of specific assays for the gonadal peptides inhibin A and inhibin B, it might be possible to achieve a clearer picture of events. We therefore determined serum levels of inhibin A, inhibin B, FSH, LH and estradiol in a cross-sectional study of 403 healthy schoolgirls (aged 6 -20 yr) in relation to age and stage of puberty and in 181 healthy nonpregnant women (aged 20-32 yr) in relation to stage of the menstrual cycle. In addition, inhibin A and inhibin B were measured daily throughout the menstrual cycle in 10 healthy adult women. Levels of inhibin B are low or undetectable in prepubertal girls (median, 26.5 pg/mL; 95% prediction interval,