Normal Sexual Development and Puberty

Puberty is the hormonally mediated process of physical changes that occur during the transition of childhood to adulthood.   Activation of the hypothalamic-pituitary-gonadal axis triggers the onset of puberty. Gonadotropin hormone-releasing hormone (GnRH) is the major regulator of the reproductive axis.  GnRH stimulates the anterior pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn activate the gonads to produce sex steroids. Thelarche is stimulated by estrogen and is usually the first sign of puberty in girls. Adrenarche, although associated temporally with puberty, is mediated by the adrenal cortex and is unrelated to pubertal maturation. A growth spurt occurs mid-puberty.  Menarche, usually occurring 2-3 years after thelarche, is considered the end of puberty. After menarche, only about 1-2 additional inches of height are accrued.  Understanding what is considered the normal timeline of sexual development allows better recognition of precocious or delayed puberty, both of which may be associated with serious underlying health issues This review contains 4 tables, 5 figures, and 29 references. Keywords: puberty, pubertal development, hypothalamic-pituitary-gonadal axis, thelarche, menarche, normal sexual development