Pregnancy Blood Test - Triple Test

What happens when the blood test brings bad news?

Most expecting mothers would be asked by their gynae to take a blood test, especially for women over 35.

This blood test is also known as the Triple Test. It a simple extraction of blood from the mother and it is harmless to both the baby and mother. The triple test is performed between the 15th and 17th week of pregnancy.

The blood sample is measured for the amount of three specific proteins in a pregnant woman's blood mainly used to identify pregnancies which may be at increased risk for Down syndrome, Neural tube defects and possible birth defects. It will take a couple of days for the results to be known.

The triple test is strongly recommended for women who:

  • Are 35 years or older
  • Have diabetes and use insulin
  • Have a family history of birth defects
  • Had a viral infection during pregnancy

If the results show abnormality, it does not mean there is any confirmed birth defect.

When I did my triple test for my second pregnancy, it suggested that I had a 1:120 chance of giving birth to a baby with Down syndrome. That alarmed my husband and me. Our gynae explained it to us in a very simple and effective way. What it meant was that the possibility was higher than comfort level but the probability was like having to draw that single defective ball out of a pail with 119 perfect balls. At the time, 119 don’t seem that many. The good news was my son was born normal and healthy.

Your gynae may suggest doing amniocentesis to confirm the findings. Amniocentesis involves extracting fluid from the amniotic sac (within which the baby lives) inside the uterus for further testing. Unlike the triple test where blood is withdrawn from your arm, amniocentesis poses a possible risk to the baby. Amniocentesis is generally a safe procedure; it has a less than 1% risk of fetal loss.

If your triple test returns with unfavorable results, do you take the amniocentesis test? That is a question I will address in my other article “Down syndrome”. It is a good idea to seek a second opinion or it is recommended by a qualified and experience gynae or genetic counselor before deciding on your next action.

Read article on Down Syndrome »