Luteinizing hormone (LH), also called lutropin, is secreted by the anterior part of the pituitary gland. It regulates the egg production and menstrual cycle in females. Women experience a sudden rise of LH prior to ovulation, about midway through the menstruation cycle (day 14 in the 28-day cycle), a process referred to as LH Surge. In males, this hormone stimulates the secretion of testosterone that in turn promotes sperm production. LH is basically a heterodimetric glycoprotein with a chemical structure similar to other glycoprotein molecules such as human chorionic gonadotrophin (hCG), thyroid-stimulating hormone (TSH) and follicle-stimulating hormone (FSH).
What happens if someone has too little luteinizing hormone?
A healthy level of LH is needed for ovarian and testicular function and its deficiency causes the failure of gonads (hypogonadism). In women, poor levels of LH stops ovulation resulting in amenorrhea, while in males, it results in low sperm count. Both these conditions contribute to infertility. Other conditions commonly associated with low LH secretions include Pasqualini syndrome, Kallmann syndrome, hypothalamic suppression, hypopituitarism, eating disorders, female athlete triad and hyperprolactinemia. Individuals with LH deficiency undergo a hormonal therapy during which a physician administers the luteinizing hormone-LH in the form of drugs such as Repronex , Menopur and Luveris.
What happens if LH levels are too high?
Too much of LH in a person’s body can be an indication of infertility. Because the production of LH is strictly controlled by the pituitary-gonadal pair, high levels of the hormone may denote reduced sex steroid production from the ovaries (as found in premature ovarian failure) and the testes. Abnormally high levels of LH may also be due to Klinefelter’s syndrome, in males. In females, it can indicate polycystic ovary syndrome or Turner syndrome. Also, children with high LH levels reach puberty too early.
The Luteinizing Hormone Test:
A luteinizing hormone test, which is performed using a urine or blood sample, determines the hormone’s levels in the body. It is commonly done to find the reason for a couple’s inability to conceive. The test evaluates numerous factors including a women’s egg supply and a man’s sperm count. It helps to determine menstrual problems, such as amenorrhea (absent or irregular periods) and to know if a child is going through precocious puberty (or early puberty). The girls and boys with this condition reach puberty before 9 and 10 years of age, respectively. The LH test also determines the reason for delayed puberty and how a woman responds to medications that stimulate ovulation.
About four weeks prior to taking the LH test, the subject will be asked to stop taking medications containing estrogen or progesterone as they may change test results. Other tests such as bone scan or thyroid scan, when done within 7 days, can also interfere with test results. So, it is mandatory to notify your physician about them before taking the test.