Prenatal screening and diagnosis
Every pregnant woman has the option of tests early in pregnancy to detect possible abnormalities in her baby. This is what we call prenatal screening. You may never have given it any thought, which is understandable — the great majority of babies are, thankfully, born healthy. There are several forms of screening: the NIPT, the 13-week scan and the 20-week scan. We will discuss these with you at your first appointment if you would like us to.
For both prenatal screening and any follow-up testing, it is entirely your choice whether to have it done. You may also decide not to receive information about the tests at all, or to decline them after having them explained.
Deciding for or against prenatal screening can be hard. What matters is making a choice that fits your own feelings and your ideas about pregnancy and life.
For help in making that choice, see www.pns.nl/nipt/hulp-bij-het-kiezen.
The 13-week scan
The 13-week scan has been offered since 1 September 2021. You can have it from twelve weeks and three days up to and including fourteen weeks and three days of pregnancy.
It is a medical examination to detect physical abnormalities in your baby. The baby's sex is not looked at. The 13-week scan is much like the 20-week scan; the difference is that later in pregnancy the baby is bigger, so more detail can be seen. The scan can usually be done through the abdomen, but sometimes an internal scan gives a better view. It takes about 30 to 45 minutes.
The 13-week scan forms part of the IMITAS research study. If you choose to have it, you automatically take part in that study, anonymously.
See this page for more information.
The 20-week scan
The anomaly scan is commonly known as the 20-week scan. It is done between eighteen and twenty-one weeks of pregnancy and looks for physical abnormalities in the unborn child. This scan examines the development of the organs in detail. It also checks the baby's growth, the amount of amniotic fluid and the position of the placenta.
Examples of things that can be seen at the anomaly scan are spina bifida, an open skull, a cleft lip, water on the brain, heart conditions, a hernia or gap in the diaphragm, a hernia or gap in the abdominal wall, missing or abnormally shaped kidneys, missing or abnormal bones, and abnormalities of the arms or legs.
If something abnormal is seen at the scan, what it means for your baby is not always clear straight away. You will then be offered follow-up testing at a specialist hospital. Our region usually refers to MST in Enschede or the UMC in Nijmegen, where the findings are investigated further. Sometimes an amniocentesis is offered alongside a further scan.
The follow-up may show that there is nothing wrong with your child, in which case you can be reassured. It may also show that you are expecting a child with a physical abnormality. With certain conditions it is better for the baby to be born in a specialist hospital, so that it can receive the right care immediately after birth. Some conditions are so serious that the baby may die before or during the birth. That faces you with difficult choices: continuing the pregnancy or ending it. If a result is abnormal you will always have a conversation with one or more medical specialists, who will give you as much information as they can and help you make the right choice for your pregnancy.
Because the anomaly scan is aimed at detecting physical abnormalities in the unborn child, it is not a keepsake scan.
NIPT
The non-invasive prenatal test (NIPT) is a blood test for chromosomal conditions. It examines DNA from the unborn child, which is present in the pregnant woman's blood. The test cannot cause a miscarriage. The NIPT is paid for by the government. If your NIPT result is abnormal, you can choose to have follow-up testing; your health insurance covers the cost of that from the basic package, though you will usually pay part of your excess first.
The NIPT can be done from 10 weeks of pregnancy by taking blood from your arm. The result is known within ten days and we let you know in writing and/or by telephone. The result is either abnormal or not abnormal. If it is abnormal, there is a strong chance your baby has a chromosomal condition. If it is not abnormal, the chance of one is very small (1 in 1,000). The NIPT does not give complete certainty. About 90% of the DNA in a pregnant woman's blood is her own and about 10% comes from the placenta. The placenta's DNA is nearly always the same as the baby's, but not always, which is why the result cannot be a full guarantee. An amniocentesis can give clarity here.
For more information, see www.pns.nl.