A Juul
Minipuberty refers to a specific period in early postnatal life with high activity of the hypothalamic-pituitary-gonadal (HPG) hormone axis. In infant boys 1 to 3 months of age, high concentrations of follicle-stimulating hormone and luteinizing hormone are released, which results in high levels of gonadal hormones from testicular Leydig cells (testosterone and insulin-like 3) and Sertoli cells (inhibin B and antimüllerian hormone). The HPG axis is also active in infant girls, who have adult levels of follicle-stimulating hormone and luteinizing hormone during this period. Immediately after minipuberty, the HPG axis is silenced for approximately 10 years and is reactivated only with the onset of puberty. Thus, minipuberty represents an early window for diagnosing disorders of sexual differentiation and rare endocrine disorders, such as congenital hypogonadotropic hypogonadism, and may help guide dosing of therapeutic interventions including gonadotropin therapy. Of note, minipuberty predicts adult reproductive capacity.