Testosterone (for Female), Serum

Specimen requirement

Adult patient (for female):

 

Clotted blood tube (Serum gel separator clot activator tube)

 

Minimum blood volume: 5 mL
Paediatric patient:

Paediatric clotted blood tube

Number of vials: 1

Minimum blood volume: 0.8 mL

Authorisation code required

No (for female or unknown sex);
Yes (for male)

24 Hr available service

No

Method

Liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Reference interval (nmol/L)

(Unit: nmol/L)

Age Female (F) Male (M) Unknown Sex (U)
0 – < 1 month < 0.8 < 6.5

F: < 0.8;
M: < 6.5
1 – < 3 months < 0.6 2.5 – 11.9 F: < 0.6;
M: 2.5 - 11.9
3 – < 5 months < 0.5 < 7.0
F: < 0.5;
M: < 7.0
5 – < 7 months < 0.5 < 2.0 F: < 0.5;
M: < 2.0
7 months – < 1 year < 0.5 < 0.6 -
1 – < 6 years < 0.5 < 0.5 -
6 – < 8 years < 0.7 < 0.9 -
8 – < 11 years < 1.2 < 1.5 -
11 – < 12 years < 1.4 < 9.0 -
12 – < 14 years < 1.4 < 14.6 -
14 – < 18 years < 1.4 < 34.7 -
> 18 years < 1.7 8.3 – 32.9 -

(Source:

  1. Paediatrics (< 18 years): Modified from Quest Diagnostics Laboratory (https://www.questdiagnostics.com/testcenter/TestDetail.action?ntc=15983&searchString=testosterone)
  2. Adult females (> 18 years): Reference Range was derived locally from 180 apparently healthy females.
  3. Adult males (> 18 years): Modified from Mayo clinic.
    (https://www.mayocliniclabs.com/test-catalog/Clinical+and+Interpretive/83686) (accessed on 10/9/2020))

Clinical indication

Testosterone (for female) is measured by LC-MS/MS method with enhanced sensitivity and specificity. This test measures total testosterone and is intended for paediatric and female patients who are expected to have low testosterone level.

Assessment of hyperandrogenism in females with clinical symptoms of hirsutism, virilisation and oligomenorrhoea. Evaluation of ambiguous genitalia, delayed or precocious puberty in paediatric patients. Diagnosis of androgen-secreting tumor.

Result interpretation

Testosterone is secreted by the adrenal glands and testes in males and by the adrenal glands and ovaries in females. Testosterone exists in serum as both unbound (free) fractions and bound fractions to albumin and sex-hormone-binding globulin (SHBG).

Excessive production of testosterone induces premature puberty in boys and masculinity in girls. In females, excess testosterone production results in varying degrees of virilisation, including hirsutism, acne, oligomenorrhea, or infertility.

Causes of pronounced elevation in testosterone level include congenital adrenal hyperplasia (CAH); androgen-secreting adrenal, testicular, and ovarian tumors; and exogenous use of testosterone or gonadotrophins.

Measurement of uncertainty

See table.

Frequency of measurement

Weekly