Prenatal Test - AFP Test

Prenatal Test - AFP Test

AFP Testing a blood test that is conducted during weeks 16 and 18 of your pregnancy.  AFP, or alpha-fetoprotein, is a protein which is made by unborn babies and excreted through the liver into your blood.  A too low or too high reading of AFP signals that the pregnancy should be checked carefully. 

AFP testing can indicate that a pregnancy could be further along then originally though, or not as far along.  It can detect multiple fetuses and identify risks such as premature delivery or a low birth weight baby.  Additionally, it can identify neural tube defects and other severe birth defects.

Neural tube defects are birth defects that include the brain or part of the spinal cord.  These include anencephaly and spina bifida.  Babies with anencephaly are almost always stillborn or die shortly after birth.  Spinal bifida is when the spinal cord and nerves are exposed outside the body.  Babies that survive with spinal bifida usually have medical problems, and some can be quite severe.  There are other types of spinal bifida where the defect is covered by skin.  The medical problems are usually still present, although less severe.  This type of spinal bifida is usually not detected by an AFP test.

The AFP test is simple and safe.  It is minimally invasive, and includes a laboratory blood draw.  It can give your doctor information to indicate if your pregnancy should be considered high risk and can help determine if your due date needs to be adjusted.  If an abnormal level of AFP is found your doctor might recommend further testing to determine the cause because  AFP is only a screening test.

There is some controversy over the accuracy of this testing, some studies suggest that there is an 80% (or greater) chance of inaccurate results.  While there is no great risk to having an AFP test, a false result could lead to further testing that might hold a greater risk.

AFP has been recommended by The American College of Obstetricians and Gynecologists to be offered to all pregnant women.  However, this test is not mandatory.  Your doctor may ask you to sign a waiver if you refuse to have this test. 

Each pregnancy, expectant mother, and unborn child is different. Your pregnancy may not progress the same as the information found here. The information here is based on the average pregnancy. It's not meant to be a replacement for any advice your may receive from your doctor. If you have any concerns about your pregnancy, we advise you to contact your doctor.

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