Clinical Significance
Prolactin, 5 Specimens - During pregnancy and postpartum lactation, serum prolactin can increase 10 to 20-fold. Exercise, stress, and sleep also cause transient increases in prolactin levels. Consistently elevated serum prolactin levels (greater than 30 ng/mL), in the absence of pregnancy and postpartum lactation, are indicative of hyperprolactinemia. Hypersecretion of prolactin can be caused by pituitary adenomas, hypothalamic disease, breast or chest wall stimulation, renal failure or hypothyroidism. A number of drugs, including many antidepressants, are also common causes of abnormally elevated prolactin levels. Hyperprolactinemia often results in galactorrhea, amenorrhea, and infertility in females, and impotence and hypogonadism in males. Renal failure, hypothyroidism, and prolactin-secreting pituitary adenomas are also common causes of abnormally elevated prolactin levels.

Preferred Specimen(s)
1 mL serum per specimen

Minimum Volume
0.5 mL per specimen

Collection Instructions
Note time on tubes

Transport Container
Serum separator tube (SST®)

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 5 days
Refrigerated: 7 days
Frozen: 28 days

Patient Preparation
Overnight fasting is preferred

Methodology
Immunoassay (IA)

Reference Range(s)
Adult Male    2.0-18.0 ng/mL
Adult Female     
  Non-Pregnant    3.0-30.0 ng/mL
  Pregnant    10.0-209.0 ng/mL
  Postmenopausal    2.0-20.0 ng/mL
Stages of Puberty (Tanner Stages)
     Female Observed    Male Observed
Stage I    3.6-12.0 ng/mL    ≤10.0 ng/mL
Stage II-III    2.6-18.0 ng/mL    ≤6.1 ng/mL
Stage IV-V    3.2-20.0 ng/mL    2.8-11.0 ng/mL