The triple marker screening test is a test that is done in order to detect signs of any genetic abnormalities such as Down syndrome or spina bifida in the baby. The test measures three different substances in the placenta during the pregnancy. The results will show the likelihood of a woman giving birth to a child with a genetic disorder or multiple children.
The Substances Measured
The three substances measured during this test is hCG, AFP and estriol. hCG or human chorionic gonadotropin, is a hormone produced in the placenta. AFP stands for alpha- fetoprotein and is a protein that is created by the fetus itself. Estirol is produced both in the placenta and by the fetus and is an estrogen hormone.
The test is performed between the 14th and the 20th week of pregnancy. The test itself is quite simple, it is quickly done and a noninvasive procedure. One simply draw some blood from the expecting woman. The blood is sent to a laboratory for testing and the results are usually ready within a couple of days.
The test is virtually pain free and over in about 5 minutes. Many intended parents wonder if the test will affect the baby in any way, but there are no known side effects of the triple marker screening test. The procedure is identical to when an ordinary blood test is administered and the woman does not have to prepare in any special way before the test.
The Accuracy of the Test
We highly recommend all pregnant women to take this test. However, it is important to know that the test is not always completely accurate, as is the case with any medical procedures. The triple marker screening test shows only the probability of genetic abnormalities or diseases. In order to find out more, further testing is required. If negative indicators are the result of the triple marker test additional testing, like for example amniocentesis, can be done. Amniocentesis is a medical procedure aimed to identify genetic disorders such as Down syndrome. It is important to remember that negative indicators does not necessarily mean that there is something wrong, it is simply a reason to investigate further.
Although all pregnant women should be offered to take the triple marker screening test it is extra important during certain circumstances. The following are situations when the triple marker screening test is highly recommended:
- If the pregnant woman is 35 years or older
- There is an existing history of genetic defects or diseases in the family
- If the pregnant woman have diabetes and uses insulin
- If the pregnant woman have used medications or drugs that might harm the fetus during the pregnancy
The results of the test are not only derived from the three tested substances. These numbers are taken into consideration and calculated in combination with a few other features in the pregnant woman such as her age, weight, ethnicity, her health status and whether or not she is having a multiple pregnancy. All of these factors combined will determine how high the risk of genetic abnormalities in the fetus will be.