Prenatal screening

Every expectant mother in the Netherlands, regardless of age and medical background, has the possibility to determine the risk of having a child with a (serious or not) ailment. The current options are:

Screening for Down’s, Edwards’ and Patau’s syndromes

If you decide to have your child tested for Down’s, Edwards’ and Patau’s syndromes, you can choose to have the NIPT (non-invasive prenatal testing). The NIPT is a ​​​​​screening test in which a blood sample from a pregnant woman is tested. The blood sample is tested in a laboratory. If this screening test shows that the baby may have Down syndrome, Edwards’ syndrome or Patau’s syndrome, follow-up diagnostic testing is needed, just to be sure. You can have a NIPT from week 11 of your pregnancy.

Read more here.

The 13-week ultrasound is a medical examination for physical abnormalities in your child. This ultrasound is very similar to the 20-week ultrasound. In both examinations, a specially trained sonographer examines your child extensively.

The 13-week ultrasound can be performed between 12+3 and 14+3 weeks of pregnancy. So from twelve weeks and three days up to and including fourteen weeks and three days of pregnancy.

Not all abnormalities can be detected yet: Some are too small to be seen at this term and some do not appear until later in the pregnancy. Imaging may also not be optimal for all pregnant women, for example due to overweight, scar tissue in the abdominal wall or position of the child. The 13-week ultrasound is not repeated if the sonographer could not see everything well. (This is in contrast to the 20-week ultrasound, which will be repeated in case of insufficient imaging)

During the 13-week ultrasound, the sonographer purposefully does not check whether it is a boy or a girl.

The sonographer will tell you the results immediately after the ultrasound. In 95 out of 100 pregnancies, the sonographer sees no indication of an abnormality. No further investigation is necessary.

Follow-up research

In about 5 out of 100 pregnant women, the sonographer sees something that could be an abnormality. It is not always clear whether it is indeed an abnormality, how bad the abnormality is and what this means for your child. Did the sonographer see anything abnormal? You can then opt for follow-up research.

If there is a suspicion of abnormalities, a pregnant woman can, if she and her partner so wish, be referred for a GUO (Advanced Ultrasound Examination) in the hospital. This is also an ultrasound that is done by a specially trained gynecologist.


This ultrasound is covered by your health insurance.

For more information, please refer

This information brochure is about screening for physical abnormalities

Scientific research

In the Netherlands you can only opt for the 13-week ultrasound if you participate in the scientific IMITAS study. This study investigates the advantages and disadvantages of the 13-week ultrasound.

This examination using medical ultrasounds looks at structural (physical) abnormalities of the unborn child. Preferably, the SEO is carried out around 20 weeks of amenorrhea (between 18+0 and 22+0 weeks of pregnancy). Hence, it is also known as the 20-week anomaly scan. We aim to complete the SEO before 21+0 weeks. The reason for this is that if abnormalities are found, any follow-up testing is often time-consuming. Once the results of the follow-up tests are available, sufficient time may need to be available to process the new information and to decide whether or not to terminate the pregnancy.

The SEO at a gestational age of 18 to 20 weeks does not find all abnormalities. It depends on the nature of the abnormality how likely it is that it can be seen. Some are too small to be seen at this time and some do not appear until later in the pregnancy. In some cases, the ultrasound imaging may not be optimal either, e.g. due to overweight, scar tissue in the abdominal wall or the current position of the baby.

A normal result of the SEO is reassuring, but it does not rule out that there are abnormalities in the fetus. Not all physical abnormalities can be seen with a medical ultrasound around 20 weeks of pregnancy. In addition, the SEO is not a genetic research either and, for example, mental limitations cannot be determined. It is important for the expectant parents to realize the limitations of SEO.

Pregnant women who decide to have an SEO carried out opt for an examination of the entire baby. The expectant mother cannot choose to not want to be informed about certain abnormalities. In addition to structural abnormalities, other relevant abnormalities may be found that require further analysis/tests (so-called secondary findings).

Follow-up tests

If the SEO rises suspicion of abnormalities, you may be referred to the hospital to carry out a GUO (“Geavanceerd Ultrageluid Onderzoek”, or advanced ultrasound examination). A specially trained gynecologist will perform this examination. There are two types:

GUO type 1: Expectant mothers who need a GUO based on their medical background, because there is a higher risk of abnormalities, are eligible for type 1. They can skip the screening stage.

GUO type 2: Expectant mothers who are referred by their midwife because there is a suspicion of an abnormality are eligible for type 2.


The SEO is fully covered by your health insurance.

This RIVM owned website provides some more background information.

This information brochure is about screening for physical abnormalities

Choose consciously

Many prospective parents find it difficult to make a choice regarding the above. We will explain the tests, if you wish, during a special consult (a counseling consultation) after your intake and hope that this will make your choice a little easier. In addition, the expectant parents receive information leaflets so that they can read them together at home in peace. Sufficient time for reflection is important for making a right choice and of course we are always willing to provide even more explanation during this reflection period.

Please do realize that not all possible abnormalities can be discovered or investigated before childbirth. If examinations and tests indicate that the chance of a child with – for example – Down syndrome is small, it may very well still have this or even another condition.

For more information regarding prenatal screening and follow-up tests, please also refer:



Would you like to register or do you have a question?
Contact us →



New location As of April 1, we will move to our new location near Emiclaer, ‘Het masker 208/210’, is under …

Dutch midwifery system

In Holland we are unique! For some women it is different, another system than in their home country. This film …

English website online

The English translation of our website is complete and now available! We welcome your feedback in case of inconsistencies, mistakes, …