Luteinizing Hormone (LH)
What is Luteinizing Hormone (LH) Test
The luteinizing hormone test measures the level of luteinizing hormone in the blood. It is a reproductive hormone produced by the pituitary gland and plays an important role in the development and functioning of eggs in females and sperms in males. Healthcare providers use this test to determine any fertility issues and disorders of the pituitary gland.
Luteinizing Hormone test is also known as Interstitial Cell Stimulating Hormone, ICSH, Lutropin, and LH.
LH is responsible for production of testosterone in males from Leydig cells of testes, and ovulation in females. It also helps in production of progesterone and estradiol, and regulates menstrual cycle in females.
The LH test determines the pituitary hormone LH levels in the blood. Inadequate levels of LH may lead to hormonal imbalance which may affect the sexual functioning of the body. Thus, getting your LH test is recommended to screen and monitor hormonal causes in case of infertility and pituitary gland diseases.
What is an LH test used for?
The LH test is used to determine:
Irregular menstrual cycles
Sperm functioning
Onset of puberty
Vaginal discharge
Tumours of the pituitary gland
Confirming menopause (end of menstrual cycles)
Who should get tested?
LH test is recommended to be performed frequently for individuals at increased risk of fertility issues. The following factors can increase the risk of infertility and may affect reproductive health:
Irregular periods
Difficulty in conceiving
Infertility
Early or delayed puberty
Sudden weight gain
Reduced or increased appetite
Low sperm count
End of the menstrual cycles (Menopause)
Test Preparation
No special preparation is required for this test. It is typically preferred to collect samples on days 2 or 3 of the menstrual cycle. The normal range may vary among different laboratories. The table below gives the normal range of LH.
Interpretation of results (International units per litre)
LH range in Males
Male: |
Before puberty – 0.3 to 6 IU/L |
Adult - 1.8 to 12.0 IU/L |
LH range in Females
Female: |
Before puberty - 0 to 4.0 IU/L |
During puberty - 0.3 to3 1 IU/L |
Pre-menopausal (follicular) -Â 1- 18 IU/L |
Pre-menopausal (Mid-cycle) - 20 to 105 IU/L |
Pre-menopausal (luteal)Â Â Â Â Â - 0.4-20 IU/L |
Postmenopausal                 - 15.0- 62.0 IU/L |
Deviation from normal results indicates the following:
- For effective reproduction, minimum quantities of LH must be present at periods during the menstrual cycle.
- Women who have high LH levels may have Turner's syndrome, primary ovarian insufficiency, ovarian cancer, or early menopause. Polycystic ovarian syndrome is characterised by a high LH/FSH ratio (PCOS).
- High LH levels in men may be a sign of sperm quality problems, Klinefelter syndrome, or testicular problems. All of these could cause male infertility.
- High levels of LH in children before puberty indicate the early beginning of puberty.
- Decreased levels of LH may prevent ovulation and reduce sperm production, which can affect both women’s and men's fertility. Low levels can result from abnormalities with the hypothalamus or pituitary gland, from being underweight or other problems with the central nervous system.
- Low levels of LH in children may indicate delayed puberty.
FAQs
What is the significance of the LH test in females?
LH promotes the development of eggs in the ovaries and helps in regulating the menstrual cycle in females. The test is used to examine or help diagnose:
- Menopause
- Women having polycystic ovary syndrome, ovarian cysts
- Abnormal vaginal or menstrual bleeding
- Problems becoming pregnant, or infertility
When should LH test be performed?
The LH test is used to diagnose male and female infertility problems. Depending on various factors like women’s age and menstrual stage, results vary. It can be used to identify any dysfunctions or irregularities in the menstrual cycle. It is also used to determine the underlying reason of infertility in women who are having difficulty becoming pregnant.
How is an LH test performed?
During this blood test, a healthcare professional will take a small amount of blood from a vein in your arm, using a small needle, which is then collected in a test tube or vial. This usually gets done in less than a few minutes.
What are the risks associated with the LH test?
There are no known risks associated with the LH test. During a blood test, one may experience minor pain or bruising where the needle was inserted, but most symptoms will subside quickly.
When should I undergo an LH test in case of PCOS?
Polycystic ovarian syndrome (PCOS) is a condition of hormonal imbalance in which ovaries (which produce eggs) produces excess hormones. Ovulation occurs 14 days before the start of your next period. Therefore, it is recommended to start LH testing a few days prior to the ovulation—around day 12.