SEO

An ultrasound examination that will be offered during pregnancy, but is not mandatory, is the Structural Ultrasound Examination (SEO). This examination is also called the 20-week ultrasound and can be performed from 18 to 22 weeks. Ideally, this ultrasound should be scheduled around 19 weeks of pregnancy. This examination is intended to detect physical abnormalities in the baby, such as spina bifida or skull. In addition, the sonographer will look at all visible structures and organs of the baby during this ultrasound The baby's growth will also be measured and the amniotic fluid and placenta will be examined. The examination is reimbursed by the health insurer. During the first check-up, the midwife will tell you more about this ultrasound examination and this topic will also be discussed during the second check-up. For more information, explanations and video pns ... you can also look at the RIVM website and read the leaflet.

video pns

kun je ook op de website van het RIVM kijken en de folder lezen.

Biometric Ultrasound

If you have an increased risk of having a small or too large baby, we will arrange additional growth ultrasounds (biometrics). During a growth ultrasound we measure the size of the head, the waist circumference and the leg length, this combination gives an estimated weight. We also check the amount of amniotic fluid and look at the position of the baby. Often these are several ultrasounds with an interval of two weeks. With us, everyone gets standard growth ultrasounds at 30 and 34 weeks of pregnancy. It may be that we need more ultrasounds. We always discuss this with you.

Eerste trimester SEO

The 13-week ultrasound is a medical examination for physical abnormalities in the baby. The 13-week ultrasound is very similar to the 20-week ultrasound. In both examinations, an ultrasound technician uses an ultrasound machine to check whether the baby has any physical abnormalities. For example, the sonographer looks at the skull, heart, abdomen, arms and legs and spine during a 13-week ultrasound. The sonographer also looks at the placenta and whether the amniotic fluid is normal. The baby is smaller and less developed at around 13 weeks than at the 20-week ultrasound. Many deviations are not yet visible. But some, often serious abnormalities do. These can be so severe that the baby dies during or shortly after pregnancy. The purpose of the 13-week ultrasound is to detect these serious abnormalities at an early stage. The sonographer can't see everything. If she doesn't see any abnormalities, this is no guarantee that the baby is healthy. Examples of possible physical abnormalities: 

  • Open skull 
  • Open back 
  • Severe abnormalities of the brain 
  • Fracture or large hole in the abdominal wall 
  • Severe facial deformities 
  • Heart defects Abnormalities of arms or legs 

You can only opt for the 13-week ultrasound if you participate in the scientific IMITAS study. The aim of the IMITAS study is to investigate whether the advantages of the 13-week ultrasound outweigh its disadvantages. Click here to read more about the IMITAS study. The research will be reimbursed. During the first check-up, the midwife will tell you more about this ultrasound examination and, if desired, give you more information about it. You will be counselled whether you want to participate in the study For more information, visit the RIVM website RIVM,, watch the video  video and read the leaflet folder




More information about the IMITAS study here 

Placental localisation

Usually as a follow-up to the SEO, the examination is repeated at 34 weeks for a low-lying placenta (placenta praevia). In our practice, growth is then determined as standard. If the placenta is on the back wall, we would also like to check internally whether the placenta is not too close to the cervix.

Gender ultrasound/fun ultrasound

If you want to look at the baby more often, it is also possible to have a fun ultrasound made with us. This is not covered by your health insurance and costs 40 euros. From about 14 weeks, a gender ultrasound is possible. During this ultrasound it is possible to see your baby and you will find out whether it is a boy or a girl. You can let us know if you would prefer that write down the gender and put it in an envelope for you.


Vitality ultrasound at 7-8 weken

An early ultrasound around 7-8 weeks of pregnancy, the sonographer checks whether the fertilized egg has implanted in the right place in the uterus (not ectopic) and whether the heart is beating. Then we check whether there are multiple births. Ultrasound can be done in two ways, externally through the abdomen or internally through the vagina. For ultrasounds before 10 weeks, we prefer an internal ultrasound. The early ultrasound is best seen with an internal vaginal ultrasound. That is why we advise you to urinate prior to this examination. Even in a later period, it can be decided to switch to an internal ultrasound if the external ultrasound does not give good image quality.

CRL/dating scan at 10-12 weken



During the ultrasound, the midwife or sonographer will measure the baby. This measurement is the CRL measurement, which is an abbreviation of the Crown-Rump Length. This measurement can be used to determine exactly how many weeks (and days) you are pregnant. This is because all babies grow at almost the same rate during the first 15 weeks. After that, there will be more individual growth differences. If the final due date after measuring the CRL measurement differs from the date calculated from the first day of your period, the ultrasound date will always be used and the due date will be adjusted.

Vitality scan at 7-8 weeks

A early scan around 7-8 weeks of pregnancy is performed to check if the fertilised egg has implanted correctly in the womb (and not ectopically) and whether the baby's heart is beating. The sonographer will also check if it is a multiple pregnancy.

Ultrasound can be done externally via the abdomen or internally via the vagina. For scans before 10 weeks, we prefer to perform an internal vaginal scan. Therefore, we recommend that you empty your bladder before this examination. In some cases, even at later stages, we may switch to an internal scan if the external one doesn’t provide clear imaging.

Dating scan at 10-12 weeks

During the dating scan, the midwife or sonographer will measure the baby. This measurement is called the CRL, which stands for Crown-Rump Length. It measures the distance from the top of the baby’s head (crown) to the bottom of their spine (rump). This measurement allows us to determine exactly how many weeks (and days) pregnant you are because all babies grow at nearly the same rate during the first 15 weeks of pregnancy.

After this period, individual growth differences start to appear. If the calculated due date based on the CRL measurement differs from the one based on your last menstrual period, we will adjust the due date according to the scan.

Structural Ultrasound Examination (SEO)

The Structural Ultrasound Examination (SEO), also known as the 20-week scan, is an ultrasound offered during pregnancy, though it is not mandatory. This scan can be performed between 18 and 22 weeks, with the ideal time being around 19 weeks. The purpose of this examination is to detect any physical abnormalities in the baby, such as spina bifida or anencephaly.

During this scan, the sonographer will check all visible structures and organs of the baby. They will also measure the baby’s growth, and assess the amniotic fluid and placenta. This scan is covered by health insurance.

Your midwife will provide more details about this scan during the first check-up, and it will also be discussed again at your second check-up. For more information, explanations, and a video about the SEO, you can visit the RIVM website and read the information leaflet.

First trimester scan

The 13-week scan is a medical examination that looks for physical abnormalities in the baby. It is similar to the 20-week scan, where a sonographer uses an ultrasound machine to check for physical abnormalities. During the 13-week scan, the sonographer examines the baby’s skull, heart, abdomen, arms, legs, and spine, as well as the placenta and amniotic fluid to ensure they are normal.

At 13 weeks, the baby is smaller and less developed compared to the 20-week scan. While many abnormalities may not yet be visible, some serious conditions can be detected. These conditions may be so severe that they could lead to the baby’s death during or shortly after pregnancy. The aim of the 13-week scan is to identify these serious conditions early. However, it’s important to note that even if no abnormalities are found, this does not guarantee that the baby is healthy.

Examples of possible physical abnormalities

  • Open skull
  • Spina bifida (open spine)
  • Severe brain abnormalities
  • Large defects in the abdominal wall
  • Severe facial malformations
  • Heart defects
  • Limb abnormalities

You can only opt for the 13-week scan if you participate in the IMITAS study. The goal of this study is to determine whether the benefits of the 13-week scan outweigh its risks. Click here to read more about the IMITAS study.

The 13-week scan is covered by insurance. Your midwife will explain more about this scan during your first check-up, and you will receive counseling on whether or not to participate in the study. For more information, visit the RIVM website, watch the video, or read the information leaflet.

Placental localisation

Typically, following the 20-week scan (SEO), if the placenta is found to be low-lying, another scan is performed at 34 weeks to check its position. In our practice, we also routinely check the baby's growth during this scan. If the placenta is positioned on the back wall, we prefer to conduct an internal examination to ensure that the placenta is not too close to the cervix.This additional check is important to assess any potential risks and ensure a safe delivery plan.

Growth scans (Biometry)

If there is an increased risk of your baby being either too small or too large, we will arrange extra growth scans (biometry). During a growth scan, we measure the size of the baby's head, abdomen, and femur length, which together provide an estimated weight. We also check the amount of amniotic fluid and assess the baby's position. These scans are often scheduled at two-week intervals.

In our practice, all expecting parents receive standard growth scans at 30 and 35 weeks of pregnancy.

If additional scans are necessary, we will always discuss this with you.

Elective ultrasound (gender determination)

If you’d like to see your baby more often, it’s possible to book an elective ultrasound with us. This is not covered by insurance and costs €40. From around 14 weeks, a gender determination scan can be done. During this scan, you’ll be able to see your baby, and you’ll find out whether it’s a boy or a girl.

You can also request that the sonographer writes down the gender and seals it in an envelope if you'd prefer to find out later.