LH and FSH are released from the pituitary gland in episodic pulses throughout life, due to episodic stimulation by hypothalamic GnRH. The amplitude of the pulses in normal prepuberty is quite small and only detectable by ultrasensitive assays. At the time of puberty, the amplitude, and then the secretory frequency, increase, leading to an overall rise in LH and FSH concentrations. FSH is secreted in greater amounts than LH in girls at all stages of development, but LH is secreted in greater amounts in boys and girls after the onset of puberty than before the onset of puberty.
