Synonyms: ICSH; Interstitial Cell Stimulating Hormone; LH

Why It Is Done

Help find the cause for a couple's inability to become pregnant (infertility). LH testing is commonly used to evaluate: * A woman's egg supply (ovarian reserve).* A man's sperm count.* Help evaluate menstrual problems, such as irregular or absent menstrual periods (amenorrhea). * Determine whether a child is going through early puberty. * Determine why sexual features or organs are not developing when they should.* Monitor a woman's response to medications given to stimulate ovulation.

Test Overview

A luteinizing hormone test measures the amount of luteinizing hormone (LH) in a sample of blood. LH is produced by the pituitary gland.

In women, LH helps regulate the menstrual cycle and egg production (ovulation). The level of LH in a woman's body varies with the phase of the menstrual cycle. It increases rapidly just before ovulation occurs, about midway through the cycle (day 14 of a 28-day cycle). This is called an LH surge. Luteinizing hormone and follicle-stimulating hormone levels rise and fall together during the monthly menstrual cycle.

In men, LH stimulates the production of testosterone, which plays a role in sperm production.

How To Prepare

No special preparation is necessary.