Pregnancy SmartSite^TM

• Home
• Email
• Site Map
• Contact

• Normal Pregnancy
• Labor & Delivery
• Complications
• After Your Child Is Born

Normal Pregnancy

Staying Healthy

Alcohol and pregnancy Managing your weight gain in pregnancy Steps to take before you get pregnant When you need to gain more weight during pregnancy

What to expect during pregnancy

Aches and pains during pregnancy Choosing the right practitioner Common symptoms during pregnancy Hyperemesis Gravidarum Morning sickness Pregnancy and travel Pregnancy and work Problems sleeping during pregnancy Skin and hair changes during pregnancy Teenage pregnancy

Preparing to go home with your baby

Cribs and crib safety Eat right during pregnancy Preparing your other children

Visits and Tests

Amniocentesis Chorionic villus sampling Genetic counseling before pregnancy Glucose tolerance test-pregnancy Monitoring your baby before labor Nuchal translucency Prenatal care in your first trimester Prenatal care in your second trimester Prenatal care in your third trimester

Prolactin blood test

Definition

Prolactin is a hormone released by the pituitary gland. The prolactin blood test measures the amount of prolactin in the blood.

How the Test is Performed

A fasting blood sample is needed.

How to Prepare for the Test

No special preparation is necessary.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

Prolactin is a hormone released by the pituitary gland. The pituitary is a small gland at the base of the brain. It regulates the body's balance of many hormones.

Prolactin stimulates breast development and milk production in women. There is no known normal function for prolactin in men.

Prolactin is usually measured when checking for pituitary tumors and the cause of:

• Breast milk production that is not related to childbirth (galactorrhea)

• Decreased sex drive (libido) in men and women

• Erection problems in men

• Not able to get pregnant (infertility in women)

• Irregular or no menstrual periods (amenorrhea)

Normal Results

The normal values for prolactin are:

• Men: less than 20 ng/mL (20 µg/L)

• Nonpregnant women: less than 25 ng/mL (25 µg/L)

• Pregnant women: less than 500 ng/mL (500 µg/L)

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

People with the following conditions may have high prolactin levels:

• Chest wall injury or irritation

• Presence of nipple rings

• Disease of an area of the brain called the hypothalamus

• Thyroid gland does not make enough thyroid hormone (hypothyroidism)

• Kidney disease

• Pituitary tumor that makes prolactin (prolactinoma)

• Other pituitary tumors and diseases in the area of the pituitary

• Abnormal clearance of prolactin molecules (macroprolactin)

Certain medicines can also raise prolactin level, including:

• Antidepressants

• Butyrophenones

• Estrogens

• H2 blockers

• Metoclopramide

• Opioid medicines

• Phenothiazines

• Risperidone

• Verapamil

Marijuana products can also raise prolactin level.

If your prolactin level is high, the test may be repeated in the early morning after an 8-hour fast.

The following can temporarily increase prolactin levels:

• Emotional or physical stress (occasionally)

• High-protein meals

• Intense breast stimulation

• Recent breast exam

• Recent exercise

Interpretation of an abnormally high prolactin blood test is complicated. In most case, your provider will need to refer you to an endocrinologist, a doctor who specializes in hormone problems.

Risks

There is little risk in having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding

• Multiple punctures to locate veins

• Fainting or feeling lightheaded

• Hematoma (blood buildup under the skin)

• Infection (a slight risk any time the skin is broken)

References

Guber HA, Oprea M, Rusell YX. Evaluation of endocrine function. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 25.

Weiss RE. Anterior pituitary. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 205.

Review Date: 7/21/2024

Reviewed By: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.