How Does The Triple Blood Test In Pregnancy Work?


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Julii Brainard answered
When the triple test is done a small sample of blood is taken from the pregnant woman to check for various blood markers (proteins) that are associated with a pregnancy where the fetus has a significant birth defect. The triple test (also sometimes called the AFP, or Alphafetoprotein test) is especially effective at detecting spinal bidufa (a developmental disorder) and Down's syndrome (a chromosone defect).

The result of the test is a single statistic, which gives your odds of the fetus having one of thse conditions. It's important to remember that the test only results in a statistic, not a definite diagnosis. Even if the results were (for example) a 1 in 3 chance of a problem, that's still a 67% chance of no such problem at all.

It's an uncomfortable fact of this type of antenatal testing that women need to think very carefully about what they will want to do with the information. You may know that there is no way you would terminate a pregnancy even if the fetus had such problems, in which case the test might be useless to you to undergo (would only serve to worry you).

It's also worth knowing that the triple test is more accurate for older women, especially after the age of 35.

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