What is a triple test?
Right away triple test the chance can be determined on a baby with Down Syndrome or an open back. It is a probability test and if the values are not good, additional prenatal tests are always done.
Triple test, how does it work?
With the triple test, blood serum is taken from the mother. Based on the concentration of three substances from this serum, the chance of a child with Down syndrome or a neural tube defect (open back) is calculated. The test can be performed from week 14 of the pregnancy.
The following substances in the mother's blood are measured in a triple test:
- Alpha fetoprotein. A higher than average concentration means an increased risk of a neural tube defect, a lower than average concentration indicates an increased risk of Down syndrome.
- Human chorionic gonadotropin. A higher concentration means an increased risk of Down syndrome.
- Estriol. A lower concentration indicates an increased risk of Down syndrome
The age of the mother is also included in the calculation of the risk of Down syndrome.
The triplet test is therefore a test to be able to calculate the probability of a deviation and unfortunately it does not provide any security. If an increased risk is observed, the amniocentesis will have to provide a definite answer.
Difference triple test and combination test? Read below the difference between these tests with additional information.
The triple test is so named because three substances are used from the blood serum. In addition, the triplet test is only done with clear suspicion. Other tests are the quadruple test on the basis of four substances, which can only be carried out later in the pregnancy. A double test is based on only two substances that occur early in the pregnancy (from 8 weeks).
The triple test was the most common in Belgium and the Netherlands, but has since been overtaken by the 1st trimester Combination Test. The latter is more reliable and the result is known faster.
The first trimester neck fold measurement combination test
In an earlier stage of the pregnancy, a better chance calculation can be determined with the first trimester combination test. The first trimester combination test consists of a blood test, in which Vrij-Beta-hCG and PAPP-A are measured in the mother's blood. These values are combined with the thickness of the neck fold (NT measurement, an ultrasound measurement), in a risk calculation program. Together with the age of the mother, the gestational age eventually gives the chance to a child with a disorder.
How long wait for triple test result
After approximately 3 working days the result of the triple test is known.
The triplet test is mainly performed in women of 36 years and older who are pregnant. From this age the chance of a child with Down Syndrome is greater. If, as a woman, you do not want to have the risk of miscarriage, as is the case with a chorionic test or amniocentesis, then Triple test a better choice.