MedlinePlus Medical Encyclopedia: Human placental lactogen

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Human placental lactogen

Contents of this page:
Alternative Names Definition How the Test is Performed How to Prepare for the Test How the Test Will Feel Why the Test is Performed	Normal Results What Abnormal Results Mean Risks Considerations References

Alternative Names

HPL; Human chorionic somatomammotropin; HCS

Definition Return to top

Human placental lactogen (hPL) is a hormone produced by the placenta, the organ that develops during pregnancy to help feed the growing baby. This hormone breaks down fats from the mother to provide fuel for the the growing baby. It can lead to insulin resistance and carbohydrate intolerance in the mother.

A test can be done to measure the amount of hPL in the blood. The test is only done on pregnant women.

How the Test is Performed Return to top

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

How to Prepare for the Test Return to top

No special preparation is needed.

How the Test Will Feel Return to top

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test is Performed Return to top

The test is done to see how well the placenta is functioning.

Normal Results Return to top

A rising HPL value during pregnancy is normal.

What Abnormal Results Mean Return to top

Abnormal results may be a sign of abnormal (usually insufficient) placenta function.

HPL values are decreased with:

HPL values are increased with:

Multiple pregnancies (twins or more)
Placental site trophoblastic tumor
Intact molar pregnancy
Diabetes
Rh incompatibility

Risks Return to top

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others. Other risks are rare, but may include:

Excessive bleeding
Fainting or feeling lightheaded
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)

Considerations Return to top

The uses of this test are limited to certain rare conditions and medical research.

References Return to top

Larsen PR, Kronberg HM, Schlomo M, et al. Williams Textbook of Endocrinology. 10th ed. St. Louis, Mo: WB Saunders; 2003.

Update Date: 5/15/2007

Updated by: Melanie N. Smith, M.D., Ph.D., Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, MA. Review provided by VeriMed Healthcare Network.

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