APPLICATION: Investigation of male and female infertility, to distinguish primary gonadal failure from pituitary/hypothalmic failure. Identification of ovulation in the investigation of menstrual cycle disturbances and female infertility. Suspected lutenising hormone (LH) secreting pituitary tumour.
INTERPRETATION: High levels are found in primary gonadal failure. Low levels occur with hypothalmic failure (responds to gonadotrophin releasing hormone) and pituitary failure (no response). LH peak occurs just prior to, and identifies, ovulation. Polycystic ovary syndrome is associated with an increased LH/FSH ratio. Interpretation of LH levels and LH responses to gonadotrophin releasing hormone is often difficult - consult a Chemical Pathologist.
