An alpha-fetoprotein (AFP) test is a simple blood test to assess the degree of AFP, a protein that develops in the fetus’s liver. It is typically a part of the quad or triple screen in the second trimester of pregnancy. AFP is produced by the baby’s liver, GI tract, and yolk sac. Non-pregnant individuals may also have AFP in their blood, but the levels are typically low. But if they are high, they indicate a liver disease.
What does the test detect?
The alpha-fetoprotein test is a routine screening test given to expecting mothers between the 14th and the 22nd weeks of their pregnancy. But doctors say it is most accurate in the 16th to the 18th week. Thus, it helps to know precisely when one conceived the baby. Typically, it is part of the quad screen, but the AFP test also has many other advantages. It can assess one’s levels of:
Estriol: A hormone generated by the baby’s liver and mother’s placenta
Human chorionic gonadotropin (HCG): A hormone yielded by the placenta
Doctors employ the quad screen results to assess the possibility of one’s unborn baby having a congenital disability. Some defects assessed in the alpha-fetoprotein test are Down syndrome or chromosomal abnormalities and spina bifida or other neural tube disorders.
Based on the test results, the doctors can determine if an individual needs further examination for these conditions. Even if the test results are positive, it does not necessarily indicate that the unborn child will have a congenital disability. The plausible advantages of the AFP test are seen more in women who are highly susceptible to bearing children with congenital disabilities. These include women who:
Are 35 or older
Have a family history of congenital disabilities
Have diabetes
Took harmful prescription or non-prescription treatments during pregnancy
Taking the alpha-fetoprotein test can benefit non-pregnant individuals as well. This test can help detect and monitor liver conditions like hepatitis, cirrhosis, and liver cancer. Further, it also helps detect other cancers involving the pancreas, biliary tract, testes, stomach, and ovaries.
How to prepare for the test?
There is no special preparation needed for undergoing the test. Ideally, one must stay hydrated by drinking plenty of water, which helps draw blood faster and more smoothly. Moreover, when a person is hydrated, there is no risk of veins constricting and tightening. Further, it also reduces the susceptibility to changes in blood pressure.
How is it done? – The procedure
The alpha-fetoprotein test is a simple blood test wherein a healthcare provider draws blood from the vein. This blood is then sent to the lab for testing, and the results are ready within one or two weeks from the day of the test. Timing is a very crucial attribute of this test. Typically, it is done between the 15th and 20th week of pregnancy. This is a common blood test that poses minimal risk to both the woman and the fetus. The only potential risks are the usual ones associated with blood tests, such as possible bruising or soreness at the site where the blood is drawn.
When a woman is pregnant, and her AFP levels are higher than usual, it could mean that the developing baby has a neural tube defect. But, it’s important to note that inaccurate dating of the pregnancy is the most common reason for elevated AFP levels. AFP levels can fluctuate significantly throughout pregnancy, so if a woman has been pregnant for a different period of time than she thought, the test results may not be accurate.
Most people find it beneficial to acquire as much information as possible to consider the probable medical interventions, get help or support, and plan for a child with special needs. Further, some people may want to know further details to decide whether or not to carry the fetus to term. Other people might wait until the child is born to fight these issues, if necessary, and it is all a personal choice.
Understanding the results
Typically, the most prevalent cause of an abnormal AFP outcome is an error in estimating the due date. However, an abnormal result may also indicate underlying problems.
Lower than normal levels imply the baby has a genetic disease that may lead to health concerns and intellectual disabilities.
Higher than normal levels mean the baby is susceptible to a neural tube defect like anencephaly or spina bifida.
Further, elevated AFP levels may indicate that one will give birth to more than one baby. Sometimes one may get a false positive result, meaning the results may be abnormal, but the baby is healthy. In case of abnormal results, the doctor will perform further tests.
Cost
The cost of an AFP test can vary between $44 and $71 across different laboratories and healthcare facilities in the country, and appointments are usually not necessary for this test.