Reference intervals for reproductive hormones in prepubertal children on the automated Roche cobas e 411 analyzer.

OBJECTIVES: To establish reference intervals for luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), progesterone (P), total and free testosterone (T) and sex-hormone binding globulin (SHBG) in prepubertal children and to assess age- and gender-related differences. DESIGN AND METHODS: A total of 948 subjects, 480 girls and 468 boys, between 1 and 11 years of age, were included in this study. All assays were performed on a Roche cobas e 411 immunoassay analyzer. Reference intervals have been evaluated according to the most recent CLSI guidelines. RESULTS: Median values of LH, FSH and T were significantly higher in subgroups ranging from ≥ 8 to < 11 years, for both genders. In girls of that age, reference values of E2 were significantly higher than in younger ones, and in boys of the corresponding age. CONCLUSION: Established reference intervals are applicable to other laboratories that use the same instrumentation.

Anti-Müllerian hormone: a unique biochemical marker of gonadal development and fertility in humans.

Anti-Müllerian hormone (AMH) is a glycoprotein belonging to the transforming growth factors (TGF-P). AMH plays a fundamental role in the regression of Müllerian ducts in male embryo. In its absence, Müllerian ducts develop into female inner reproductive organs. In boys, it is significantly produced in Sertoli cells of testes until puberty and then slowly decreases to residual values for the rest of the men's life. AMH serves as a biochemical marker of the presence of testes in cryptorchidic males. In females, AMH is secreted by granulosa cells of small follicles in the ovary. Serum values are almost undetectable during infancy and then rapidly increase with the onset of puberty, reflecting the initial recruitment of primordial follicles. AMH is produced in growing follicles until they reach a stage when dominant follicle is detached from a cohort of antral follicles. The measurement of serum AMH levels during woman's reproductive life represents an ideal tool for the assessment of the ovarian follicular reserve. The advantage of AMH in relation to the ovarian steroid hormones is that serum levels do not fluctuate significantly during the menstrual cycle. In addition, circulating AMH strongly correlates with antral follicle count (AFC), visualized by ultrasound in the follicular phase of the cycle. As the number and quality of the oocytes diminish throughout the woman's reproductive life, serum concentrations of AMH gradually decrease and fall below detectable levels in menopause. This could be of particular interest in subfertile and infertile women undergoing assisted reproductive techniques (ART) in achieving pregnancy.