Understanding Luteinising Hormone
Luteinizing hormone (LH) is produced and released in the anterior pituitary gland. This hormone is considered a gonadotrophic hormone because of its role in controlling the female and male reproductive system.
What does Luteinising Hormone (LH) do?
LH has several functions regulating the reproductive cycle:
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It causes the ovaries to release an egg during ovulation
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It stimulates the ovaries to produce estradiol
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It stimulates the corpus luteum to produce progesterone to sustain pregnancy
How is Luteinising Hormone (LH) measured?
Luteinising Hormone (LH) can be measured in blood as requested by your doctor. It can also be measured in urine, using ‘ovulation tests’ which you can buy over the counter without a prescription.
You may need several tests to notice a pattern throughout the menstrual cycle. You may notice fluctuations and a surge, which happens just before ovulation. Normal LH values are:
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Midcycle peak: 21.9 to 56.6 IU/L
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Follicular phase: 1.68 to 15 IU/L
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Luteal phase: 0.61 to 16.3 IU/L
Detecting Ovulation with Luteinising Hormone (LH)
You can measure LH levels to detect ovulation. Levels will increase 36 hours before the egg is released from the ovary, giving an indication of the best time to conceive. Your fertile window includes the 5 days before ovulation and the day of ovulation.
Abnormal Luteinising Hormone (LH) values
It is normal for LH values to fluctuate throughout the cycle.
If you have very low values and don't see a midcycle surge, you may not be ovulating. It may be related to a pituitary disorder, anorexia, malnutrition, or stress. If you have very high values, you may have PCOS, a pituitary disorder or be in menopause.
About the author
EmbryoClinic is a state-of-the-art fertility clinic located in Thessaloniki, Greece. The IVF unit boasts highly experienced staff who use the latest technology in a purpose-built assisted reproduction clinic. The staff at EmbryoClinic aim to provide a comfortable environment whilst guaranteeing patients that they will receive the best treatment.