Investigation of primary and secondary amenorrhoea, and/or gonadal failure.
Assessment of hypothalamic-pituitary function. Note that repeated sampling may be necessary in order to demonstrate impaired LH secretion because of oscillations in LH values during the day. In postmenopausal women there is less difficulty, as resting values are higher than in pre-menopausals. A pre-menopausal value in postmenopausal woman is suggestive of hypothalamic-pituitary disease. In males a low plasma testosterone with low or “normal” LH values is suggestive of hypothalamic or pituitary disease.
Detection of pre-ovulatory surge – either spontaneous or in response to clomiphene citrate. A mid-cycle LH peak precedes ovulation by 24 – 48 hours.
Polycystic ovary syndrome – some but not all of these patients (approx. 50%) may have tonically increased plasma LH levels. (FSH is normal).
Time of sampling is not critical (except for some research studies). Details of age, gender, last menstrual period and medications, (especially oral contraceptive or sex steroids) are essential. To avoid confusion with the mid-cycle LH peak it may be necessary to take two samples at least two days apart.
Ambient (8 - 24 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)
Preferably >0.5 mL serum or plasma
During the menopausal transition, which may last several months or longer, values of LH may fluctuate considerably.
Method changed from Beckman Coulter Access to Roche Elecsys on 13/4/2011.
0-9 yrs 0-2.5 IU/L
10-15 yrs Levels rise during puberty towards adult range
Adult male 2-9 IU/L
Adult female Follicular 2-8 IU/L
Mid cycle 10-75 IU/L
Luteal 2-8 IU/L
Post menopause >15 IU/L
Antenatal <1 IU/L
Two-site immunometric assay on Roche Cobas e411 analyser.
$11.56 (Exclusive of GST)
Reference intervals exclude subjects on oral contraceptives or HRT.