The triple test is a non-invasive prenatal test. The test result does not answer the question of whether the baby is he althy. However, it assesses whether you are in a group at increased risk of developing a genetic defect in the fetus. How is the triple test performed and how to interpret the results?

The triple testisaprenatal test that measures HCG, AFP, and estriol (uE3) levels. The triple test is performed to assess the risk of developing chromosomal abnormalities and defects (trisomy) in the fetus - Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and neural tube defects such as spina bifida or a condition called anencephaly. Trisomy 13, or Patau's syndrome, is not detectable by the triple test. The triple test is recommended primarily for women who have not previously performed any tests to assess the risk of congenital abnormalities. The sensitivity of the triple test is lower than that of the PAPP-A test. The triple test detects 6 out of 10 fetuses with one of the syndromes.

Triple test: mileage

The triple test is performed in the second trimester of pregnancy - between 17 and 20 weeks. You don't need to prepare yourself for it. It is safe for you and your baby. Blood is taken from a vein in the crook of the elbow. Then the level of three substances is measured in it: alpha-fetoprotein (AFP), chorionic gonadotropin (beta hCG) and estriol. The test results, your age and weight are entered into the computer. A special program compares this data with the data of a thousand he althy Polish women.

Triple test: interpretation of results

When the test results are normal, the risk of having a sick child is very low. Any abnormalities are a signal that the child's risk of developing the disease is high, and when it is greater than 1: 200, the doctor usually orders an amniocentesis.

  • decrease in AFP and uE3 concentrations and increase in HCG levels indicate the risk of Down syndrome
  • lowering all oestrogens indicates a risk of Edwards' syndrome

Triple test: what influences the reliability of the test?

Whether the test results are reliable depends very much on the correct determination of the age of the fetus. Performing a triple test (as well as a duplicate test or PAPP-A) too early or too late mayfalsify (inflate or lower) the results. Also in twin pregnancies, calculating the risk of Down-Edwards syndrome is also difficult. The results are not influenced by the time of sampling or the performance of tests on an empty stomach or after eating.

Triple test: what can be detected?

The test result does not answer the question if the child is he althy. However, it assesses whether you are in a group at increased risk of developing a genetic defect in the fetus. Incorrect (compared to he althy women) concentration of any of the tested substances is associated with a higher risk of occurrence, e.g. Down syndrome, Edwards, Turner or obstructive uropathies (the outflow of urine from the bladder is difficult, which results in, for example, serious kidney damage).

Category:

Pregnant examinations