LUTEINIZING HORMONE

Females :

• Normally Menstruating :
• Follicular Phase : 1.9 -12.5 mIU/ml
• Midcycle peak : 8.7 -76.3 mIU/ml
• Luteal Phase : 0.5 - 16.9 mIU/ml
• Pregnant : < 0.1 - 1.5 mIU/ml
• Post Menopausal : 15.9 - 54.0 mIU/ml

Children  : 

• <0.1 -6.0 mIU/ml

Males

• ( 20-70 years ) : 1.5 -9.3 mIU/ml
• >70 years : 3.1 – 34.6 mIU/ml

• Luteinizing hormone is a glycoprotein hormone secreted by the anterior pituitary gland . LH and FSH are called Gonadotropins because they stimulate the Gonads – in males , the testes and in females the Ovaries . They are necessary for Reproduction.
• In woman of child bearing age, several hormones (LH,FSH, estrogen and progesterone ) rise and fall in a specific sequence during each menstrual cycle. A menstrual cycle is divided into follicular and luteal phase, with each phase lasting about 14 days. Near the end of follicular phase, there is a mid cycle surge of FSH and LH. This surge triggers ovulation.
• During the luteal phase , the site where egg follicle ruptured becomes a corpus luteum . LH release stimulates corpus luteum to produce progesterone. FSH and LH level decline, while progesterone and estradiol concentrations increase. If the egg is not fertilised , these levels decrease and menstruation starts.
• In men , LH stimulates leydig cells in the testicles to produce Testosterone .LH levels are relatively constant in men after puberty.
• LH levels are used in Prediction of ovulation; a rising serum LH titer anticipate impending follicle rupture
• LH titers are chronically elevated in women with ovarian failure along with FSH
• In polycystic ovarian disease, LH is released in excessive pulsative bursts. Thus repeated LH measurements between 15 and 40 mIU/ml in association with normal or low FSH strongly support the diagnosis of PCOD
• Conversely LH, in association with normal FSH, may be suppressed to chronically low levels of <5 mlU/ml in women with hypogonadotropism, such as in anorexia nervosa.
• LH/FSH ratio is valuable predictive tool for hyperstimulation syndrome (OHS). Most OHS patients will have LH./FSH >1
• LH levels are also used in the different diagnosis of male hypognadism

• In adults when a woman has irregular or absence of menstrual periods, Infertility
• When a man has low testosterone levels , or when he has low muscle mass or decreased sex drive
• In Children when puberty is not attained at an appropriate age

• Menopause
• Primary ovarian hypofunction
• Polycystic ovary disease in females
• Primary hypogonadism in males
• Increased in Castration, ovarian failure
• Anorchia
• Hypogonadism
• Klinefelter's syndrome
• Precocious puberty
• Turner's syndrome
• Complete testicular feminization syndrome
• Luteal phase of menstrual cycle

• Primary ovarian hyperfunction in females
• Primary hypergonadism in males
• Hypopituitarism
• Gonadotropin deficiency
• Kallmann syndrome
• Pituitary LH or FSH deficiency