LAB TEST

Fetal-maternal erythrocyte distribution blood test

The fetal-maternal erythrocyte distribution test is used to measure the number of the unborn baby's red blood cells in a pregnant woman's blood.

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is necessary for this test.

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

Rh incompatibility is a condition that occurs when the mother's blood type is Rh-negative (Rh-) and her unborn baby's blood type is Rh-positive (Rh+). If the mother is Rh+, or if both parents are Rh-, there is no reason to worry about Rh incompatibility. If the baby's blood is Rh+ and gets into the mother's Rh-…

Normal Results

In a normal value, no or few of the baby's cells are in the mother's blood. The standard dose of Rh immune globulin is enough in this case. 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…

What Abnormal Results Mean

An abnormal test result means that blood from the unborn baby is leaking into the mother's blood circulation. The more of the baby's cells there are, the more Rh immune globulin the mother must receive.

Risks

There is little risk involved with 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…

References

Cooling L, Downs T. Immunohematology. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 36. Moise KJ. Red cell alloimmunization. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem…

This is a summary. Read the full article at www.ucsfbenioffchildrens.org (reviewed 31/07/2024).

This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.