Alpha fetoprotein is a protein made by the liver cells of an unborn baby. The level of fetoprotein can be tested by checking the expected mother’s blood and is used to detect any abnormalities in an unborn baby.
Alpha fetoprotein test is a part of the triple screening test. In addition to blood results, a screening test also considers other factors such as age and ethnicity etc.
Hence in case of a positive test further confirmatory tests should be done to confirm the problem. This test thus helps to find out the problems such as spina bifida, anencephaly, omphalocele and also the chromosomal problems like Edwards syndrome ( trisomy 18), Down syndrome ( trisomy 21) etc
Alpha Fetoprotein Test
This test is done by drawing blood from the expected mother’s vein and the result is obtained in one to two weeks time. Normally very low levels of alpha fetoprotein are seen in expected mother’s blood but when this level increases then it indicates the need for further tests.
Usually this test has to be done between 14th to 22nd weeks of pregnancy and the most accurate results are obtained during 16th to 18th weeks of pregnancy. As the level of alpha fetoprotein changes according to the pregnancy period, accurate pregnancy period plays a major role in determining the result.
Even though pregnant women can undertake this test it is usually recommended for those who are above 35 years or have family history of birth defects or have diabetes or had used harmful medications during pregnancy.
The results obtained are then compared with the pregnancy date, age of the mother, ethnicity etc and if the levels are high then the growing baby may have chances of abnormal neural tube such as anencephaly or spina bifida or there may be defect in baby’s esophagus or abdomen.
If the test result is low and if other screening tests such as estriol and hCG are showing abnormal results then the chances for chromosomal abnormalities like Down syndrome, Edwards syndrome etc are more.
Abnormal levels of alpha fetoprotein can also be a reason of multiples pregnancy or can be a pregnancy with inaccurate dating. If the first screening tests are abnormal then most of the doctors recommend for a second series of screening tests and then for amniocentesis or high definition ultra sound scanning.
These results help the couple to decide whether they want to discontinue pregnancy or can prepare themselves for a child who needs special care. Alpha fetoprotein test has no side effects and can be carried out without any risk.