Effect of prolonged illumination (phototherapy) on concentrations of luteinizing hormone in human infants.

Concentrations of luteinizing hormone in the serums of human neonates were altered when the neonates were exposed to prolonged, intense illumination (phototherapy) with their eyes covered. Concentrations decreased after 48 to 72 hours of exposure, increased 6 to 9 days after phototherapy, and subsequently returned to levels similar to those of controls. These data suggest that light may affect pituitary-gonadal function in the human neonate.