Triple Test

The triple test is a method of prenatal diagnosis that attempts to draw conclusions about peculiarities in the unborn child based on the concentration of three hormones (see below) in the blood of the pregnant woman. The test is performed between the 15th and 20th week of pregnancy.

Synonym

  • Second trimester screening

Material

  • Serum (2 ml)

From the measured blood values, taking into account the gestational age, it can be calculated whether there is an increased risk for the unborn child to suffer from trisomy 21 (Down syndrome, “mongolism”) or spina bifida (“open back”).

In every pregnancy, there is a small risk for the child to have a disorder in the genetic material and to be born with a disability as a result. The older the pregnant woman, the greater this risk. If the pregnant woman is 25 years old, one in 1,300 children will be affected by Down syndrome. If the pregnant woman is over 35 years old, one in 380 children is affected.

The procedure

Three blood parameters – AFP, HCG, unconjugated estriol – are determined in the blood, which are formed in gravidity and are altered in Down syndrome. The mother’s age (on the calculated date), gestational age (gestational age; gestational week (SSW), sonographic/ultrasound) and the number of fetuses are included in the calculation of risk. Furthermore, the following are taken into account: previous Down syndrome, neural tube defect and insulin-dependent diabetes mellitus (blood sugar disease). Thus, a possible individual risk for trisomy 21 (Down syndrome) of the child can be calculated.

Detection rate

Syndrome name Detected by the test
Down syndrome (trisomy 21) approx. 74 %
Edwards syndrome (trisomy 18) approx. 70
Paetau syndrome (trisomy 13) 100 %
Triploidy 100 %
Turner syndrome (monosomy X) 100 %
Klinefelter syndrome (XXY) 75 %
Neural and abdominal wall defects 80 %

Benefit

The triple test determines your individual risk for trisomy 21 (Down syndrome) in your child. Necessary, further examinations to confirm the diagnosis can be initiated in time.

You increase your own safety and that of your child by taking the triple test.