During your pregnancy you may choose to have prenatal screening. The screening consists of tests, which can detect potential (chromosomal) abnormalities in your unborn child. Once you have registered at the practice, you will receive an email with additional information on this topic. It is important that you read this information well prior to the first consultation at the practice. During your first consultation we will discuss this in a lot more detail and there will be ample time for us to answer any questions you may have. There are a number of possible tests:
- Non-Invasive Prenatal Test (NIPT)
- Combination test
- Structural Ultrasound Examination (SEO)
Non-Invasive Prenatal Test The NIPT is a test during which the blood of the mother is checked for hereditary material (DNA) originating from the placenta. This DNA is nearly always equal to the baby’s DNA. In the laboratory the DNA is tested for the likelihood of your child having Down-, Edwards- or Patau’s syndrome, also known as trisomy 21, trisomy 18, and trisomy 13. For this examination blood is taken from the arm. This does not increase the chances of a miscarriage. How reliable is the NIPT? The NIPT does not provide 100% certainty. Research shows that the NIPT can indicate the following: – 96 of 100 children with Trisomy 21 – 87 of 100 children with Trisomy 18 – 78 of 100 children with Trisomy 13. The test result of the NIPT can be abnormal or not abnormal. An abnormal test result means that there are strong indicators that the unborn child has a trisomy 21, 18 or 13. However, in the event of an abnormal test result there is still a chance that the child does not have a trisomy. Therefore, a villus test or amniocentesis is required to confirm the NIPT test result. Villus testing and amniocentesis both increase the chances of a miscarriage slightly (0.1-0.2%) The majority of test results are not abnormal. In case of a not abnormal test result, the chances of your child still having a trisomy is so small (smaller than 1:1000) that a subsequent test is not recommended. When pregnant women with an increased change of a trisomy have the NIPT test and the result is not abnormal, a villus test or amniocentesis is no longer required. The NIPT can be carried out from week 11 in your pregnancy. The costs for the NIPT are 175 euro and are not covered by your health insurer. Combination test The combination test is a combination of two tests to which a probability calculation is applied:
- A maternal blood test where certain hormone levels in the blood are reviewed in the laboratory.
- An ultrasound between 11 and 14 weeks pregnancy, where the nuchal fold will be measured. The nuchal fold is a layer of fluid at back of the neck of the baby. The thicker the layer is, the greater the chance of the baby having Downs-, Edwards- or Patau’s syndrome.
An ‘increased chance’ means there is a chance of 1 in 200 of your child having Downs-, Edwards- or Patau’s syndrome. A chance of 1 in 200 means that out of every 200 pregnant women at the time of examination one is carrying a child with Downs-, Edwards- or Patau’s syndrome. The other 199 women carry a child that does not have Downs-, Edwards- or Patau’s syndrome. And increased chance is therefore not the same as a big chance. How reliable is the combination test? The combination test calculates the chance of your child having Downs-, Edwards- or Patau’s syndrome. The test does not provide certainty. In case of an increased chance of your child having Downs-, Edwards- or Patau’s syndrome you may choose to have a subsequent test or not. There is an increased risk starting from a chance of 1 in 200. Subsequent testing is required to establish with certainty whether or not the baby has one of these conditions. If the chance of having a child with Downs-, Edwards- or Patau’s syndrome is less than 1 in 200 (for example 1 in 100), no subsequent testing is required. The combination test does not guarantee 100% certainty. A small change of you child having Downs-, Edwards- or Patau’s syndrome will remain. Research shows that the combination test can indicate the following: – 85 of 100 children with Trisomy 21 – 77 of 100 children with Trisomy 18 – 65 of 100 children with Trisomy 13. The costs for the combination test are 170 euro and are generally not covered by your health insurer. Structural Ultrasound Examination This medical examination is also known as the 20 weeks ultrasound scan and is carried out between 19 and 21 weeks of pregnancy. An ultrasound scan is used to determine whether or not the child has any psychical abnormalities. It does not provide 100% certainty that the child is completely healthy. However, many abnormalities can be detected using an ultrasound scan. In 95 out of 100 pregnancies no abnormalities are observed. Subsequent tests are not required. In case of a suspicion of an abnormality an extensive ultrasound scan is carried out at a centre for Prenatal Diagnostics. This is called an Advanced Ultrasound Examination (GUO). The costs for the Structural Ultrasound Examination are covered by the basic health insurance package. Important websites Information about the NIPT (study format) www.meerovernipt.nl www.onderzoekvanmijnongeborenkind.nl Help centre www.onderzoekvanmijnongeborenkind.nl/keuzehulp-bewust-kiezen Frequently Asked questions about the NIPT www.onderzoekvanmijnongeborenkind.nl/veelgestelde-vragen-nipt Information about the combination test www.onderzoekvanmijnongeborenkind.nl Information about the Structural Ultrasound Examination www.onderzoekvanmijnongeborenkind.nl