Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Luteinising hormone (LH) is a glycoprotein produced by the basophilic cells of the anterior pituitary under the control of hypothalamic gonadotropin releasing hormone. LH in females causes ovulation and steroid (oestrogen and progesterone) production by the corpus luteum. In the male, LH stimulates the interstitial cells (Leydig cells) to produce androgens and oestrogens. Circulating LH is regulated via steroid hormones exerting negative feedback on the hypothalamus. The clinical utility of LH determination (and that of FSH) is in the investigation of function of the hypothalamic-pituitary-gonadal axis.
Specimen container paediatric:
serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
0.5 mL
Minimum volume adult:
1 mL blood
Sample stability:
Unseparated sample: 7 days
Separated sample:
3 days at 15-25°C,
14 days at 2-8°C,
6 months at -20°C
Transport requirements:
Ambient
Interpretation:
Elevated LH concentrations are associated with primary gonadal failure. Low LH concentrations may be associated with hypogonadotrophic hypogonadism (i.e. GnRH deficiency) or due to suppression of GnRH secretion due to high concentrations of testosterone in men (e.g. in testosterone replacement therapy) or oestrogens in women (e.g. due to exogenous oestrogens or pregnancy).
Reference ranges:
Male:
1.7 – 8.6 IU/L
Female:
Follicular: 2.4 – 12.6 IU/L
Luteal: 1.0 – 11.4 IU/L
Ovulation: 14.0 – 95.6 IU/L
Postmenopausal: 7.7 – 58.5 IU/L