AFP is a protein made by the baby and secreted into the amniotic fluid and mother's blood stream. Elevated levels of AFP can be found in certain conditions such as spina bifida, anencephaly (failure of brain and skull development), abdominal wall defects, fetal death, twin gestation, or inaccurate dating of pregnancy. An elevation of AFP, even with a normal amniocentesis, can be associated with a higher risk of problems in the third trimester. Some of these include placental separation (abruption), preterm labor, poor fetal growth, pregnancy induced hypertension, increased risk of stillbirth, and a lack of amniotic fluid. Low levels of AFP have been associated with a higher risk of chromosome problems such as Down syndrome.

Screening of the mother's blood allows us to check for the possibility of some of these potential problems. The blood test that is drawn is called a Quad Screen or Maternal Serum Screen 4. It includes an AFP, an estrogen level, an HCG level, and inhibin A level. The Quad Screen is more accurate at predicting a chromosome problem compared to the AFP alone. The majority of babies born with Down syndrome are born to women under the age of 35, even though the risk of Down syndrome increases at the age of 35. At the age of 35, the risk of having a baby with Down syndrome is 1:270 live births. An amniocentesis is usually recommended for women who will deliver by the time they are 35 or older. For those younger than 35, the Quad Screen will detect about75 percent of Down syndrome babies. The AFP will be elevated in greater than 90 percent of cases involving brain, spinal cord, or abdominal wall defects. An abnormal Quad Screen can be a false alarm, therefore if a quad-screen or AFP is abnormal, an ultrasound is recommended. An amniocentesis could determine if a problem really exists. A normal Quad Screen does not necessarily guarantee a normal baby.

The AFP, Quad Screen, and amniocentesis are recommended, but are all optional tests. A decision whether to have the test or not is usually a personal choice. A woman who would not have an abortion may still want to consider the testing in order to help prepare herself, her family, and her doctors for the birth of a baby with special needs.

A woman who is 35 or older needs to be aware that, even with a normal Quad Screen and ultrasound, there is still the possibility of having a baby with Down syndrome. Most chromosomal abnormalities other than Down syndrome are not detected by the Quad Screen. At times, Trisomy 18 can be detected with an abnormal quad-screen. An amniocentesis or a procedure called chorionic villous sampling (CVS) are the most accurate tests for diagnosing Down syndrome as well as some of the other chromosomal problems.

If you choose to have this test done, the blood work should be drawn between 15 and 18 weeks, along with other prenatal laboratory work. The results are usually returned to our office in approximately one week. If you are 35 or older and are going to have an amniocentesis, we draw just the AFP a few days before your amniocentesis. This will help us determine if you will be at risk of any of the third trimester problems mentioned previously.

I understand and wish to have the Quad Screen done.

Signed: ____________________________________

Date: ________________

I understand and DO NOT wish to have the Quad Screen done.

Signed: _____________________________________

Date: ________________

This information is provided as a resource onlyand not intented to be a recommendation or a substitute for consultationwith your physician regarding your health and needs.