In the Netherlands all pregnant women receive the possibility of testing the health of their unborn baby. Part of these tests consist of calculation of probability where your individual change of having a baby with one of the following chromosomal abnormalities will be determined:
Chromosomal abnormalities
- Downsyndrome: one extra chromosome is 21 (trisomia)
- Edwardsyndrome: one extra chromosome 18
- Pautaussyndrome: one extra chromosome 13
The Non-Invasive Prenatal Test
The Non-Invasive Prenatal Test (NIPT) is a blood test for pregnant women. In the blood, the DNA of the placenta will be examined. The DNA of the placenta matches the baby’s DNA in most cases. By examining this DNA, the baby will be checked for possibly having chromosomal abnormalities. In the Netherlands the NIPT test is provided inside the Trident study only. The NIPT is safe for pregnancy and does not give an increased risk of miscarriage.
When: The NIPT can take place from 11 weeks pregnancy
Calculation of probability
The NIPT is a quite accurate calculation of probability. Non-deviant results are accurate for more than 999 out of 1000 women. When the results do show abnormalities, the chance of accuracy differs per syndrome. For down syndrome the accuracy is 75%, for Edwards syndrome 24% and for Pataus syndrome 23%. In these cases, a Chorionic villus test or amniocenteses will have to provide more certainty.
Ancillary findings
There is a possibility that different chromosomic abnormalities are found in the DNA of the child, placenta or (very rarely) the pregnant mother herself. We call these findings ancillary findings.
There are several kinds of ancillary findings: from very severe to less severe disorders. Out of every 1.000 pregnant women that choose NIPT, about 4 turn out to have a chance of an ancillary finding. To be sure about the kind of ancillary finding further examination is necessary, usually a chorionic villus test or amniocenteses.
Insurance coverage
Because the NIPT is part of the Trident study, health insurance covers a part of it out of the basic insurance. It also involves a personal contribution of approximately € 175,00. In case of a medical indication or enlarged risk, the follow-up tests will be covered out of the basic insurance.