Throughout your pregnancy, ultrasounds are performed to monitor the evolution and development of the fetus.
Early ultrasound
An ultrasound performed in early pregnancy (between 6 and 11 weeks) serves, in the first place, to define the age of pregnancy and its evolution. It also makes it possible to determine the position of the pregnancy inside the uterus as well as the number of embryos.
First trimester ultrasound
This examination, also called "dating ultrasound" is performed between the 11th and 14th week.
It makes it possible to:
- See that your pregnancy is progressing favorably.
- Confirm the term of your pregnancy.
- Do an initial examination of your fetus' anatomy.
- Screen for certain chromosomal abnormalities.
- Screen for pre-eclampsia.
Chromosomal abnormalities
Combined screening
This screening determines the risk that your fetus is carrying a chromosomal abnormality such as trisomy 21 (Down syndrome). This calculation takes into account maternal factors (e.g. age, ethnicity), blood markers (beta hCG and PAPP-A) and ultrasound measurement of a small fluid space at the nape of the fetus, nuchal translucency. Combined screening can detect trisomy 21 in 90% of cases.
Depending on the risk obtained during this screening, additional tests will be discussed with you.
Non-invasive screening
Non-invasive screening (NIPT) consists of a blood test taken from the mother. DNA fragments from the placenta circulate in the maternal blood. The laboratory is able to detect them. It can thus determine the presence of certain chromosome abnormalities. NIPT can detect trisomy 21 in > 99% of cases.
Screening for pre-eclampsia
Pre-eclampsia is a pregnancy-related disease that can cause maternal and fetal complications.
Screening is based on maternal factors (age, history...), blood markers (PLGF and PAPP-A), ultrasound measurement of blood flow in the arteries of the uterus and your blood pressure.
Knowing that you are at risk of developing this disease allows us to offer you a prophylactic treatment with low doses of aspirin.
Morphological ultrasound
This examination is ideally performed between the 20th and 22nd week of amenorrhea and is used to look for possible fetal malformations.
At this stage of pregnancy, the fetus is sufficiently developed that we can examine its anatomy in detail.
We will also look at the appearance and position of the placenta, the length of the cervix, and the flow of blood through the mother's uterine arteries.
Fetal malformations
It may happen that a malformation is found in your baby. In this situation, our team, which works in a network with other specialists, will accompany you in the care which will include:
- an invasive examination
- genetic analysis
- an antenatal consultation by a specialist paediatrician (for example : cardiologist, neurologist, surgeon, ...)
- regular ultrasound follow-up
- additional tests such as an MRI
We always work closely with your gynaecologist to best support you in this situation.
Third trimester ultrasound
The purpose of the third trimester examination (after 26 weeks) is mainly to assess the well-being of your fetus. It can be indicated in many situations such as :
- Evaluation of fetal growth
- Position of the fetus
- Measurement of the amount of amniotic fluid
- Doppler flow measurement
- Twin pregnancy monitoring
- Follow-up in case of fetal malformations
- Position of the placenta
- Cervical length measurement
- Measuring the thickness of the bottom segment
Invasive examinations
Chorionic villus puncture and amniocentesis are diagnostic tests. The sample is taken through the abdominal wall of the mother. These examinations may be indicated in situations such as :
- A screening test suggesting an increased risk of genetic abnormality
- Ultrasound discovery of a malformation that may be associated with a genetic problem
- A risk of transmission of a genetic abnormality in the family
- Suspicion of a fetal infection
Chorionic villus puncture (PVC)
A chorionic villus puncture involves removing a small amount of placental tissue. It can be performed from 11 weeks.
After locating the position of the placenta on ultrasound, the doctor will disinfect your belly. A local anesthetic will be injected under the skin. The puncture needle will be inserted under ultrasound control to the placenta in order to take the sample.
Amniocentesis
An amniocentesis involves removing a small amount of amniotic fluid from surrounding your baby. It can be done from the 15th week.
After locating the position of the fetus and placenta on ultrasound, the doctor will disinfect your belly. A puncture eel will be inserted under ultrasound control to the amniotic bag in order to take the sample.
