Understanding and making decisions: a detailed look at prenatal tests
Are you pregnant and wondering whether your baby is healthy? Prenatal diagnostics offers various tests that can reveal information about potential illnesses. Which specific prenatal tests are offered, and what does it mean if a result is abnormal?
This article summarises the key information that will help you to make good decisions.
-
Short and simple
Babies can be tested before the birth.
These tests reveal potential illnesses.
There are a variety of tests.
They are always voluntary.
Parents can get help and advice.
Which prenatal tests are available?
Non-invasive prenatal diagnostics (NIPTs Testing)
The term non-invasive prenatal diagnostics refers to tests that do not involve physically entering the mother’s body in any way, meaning that they are not dangerous for the baby. These tests can reveal information about how likely the baby is to have a certain illness or disability. However, they do not provide a clear diagnosis. Invasive tests – i.e. tests that involve entering the body and taking samples – are required for that. In general, non-invasive tests take place before an invasive method is used.
There are four non-invasive prenatal diagnostic methods:
- Ultrasound
- Nuchal translucency test (measurement of the fold at the back of the baby’s neck)
- First trimester screening
- Non-invasive prenatal testing (NIPT)
Among other things, ultrasound scans can be used to assess the baby’s growth and heartbeat, the blood supply to the baby and the quantity of amniotic fluid. It is also possible to see the baby’s position and obtain information about possible organ damage such as heart defects or spina bifida (incorrect development of the spinal cord).
Routine ultrasound scans are conducted at regular intervals, and further scans can be performed at any time in the event of abnormalities.
The nuchal translucency test involves measuring the thickness of the fluid under the skin at the back of the baby’s neck with ultrasound. Small quantities of liquid are entirely normal. If too much liquid is present, however, this can be an indication of a possible chromosomal disorder. The scan takes place between the 11th and 14th weeks of the pregnancy.
The first trimester screening can be carried out between the 12th and 14th weeks of the pregnancy. It is a combination of two tests:
- Measurement of nuchal translucency in the baby
- Blood test in the mother
The results of the tests are combined with the mother’s age to calculate the risk of the most frequent trisomies, 13, 18 and 21. However, this is not a diagnosis – it is merely an indication of the probability.
If the risk is elevated, the next step can be either to perform non-invasive prenatal testing (NIPT) or to carry out invasive tests to obtain a definitive diagnosis.
DNA cells from the baby circulate in the mother’s blood. From the 12th week of pregnancy, non-invasive prenatal testing (NIPT) can be used to analyse the child’s DNA from the placenta. To perform this test, a blood sample is taken from the mother. NIPT can provide indications about the presence of trisomy 13, 18 and 21 in the unborn child. Abnormal findings can be confirmed with invasive tests.
Invasive prenatal diagnostics
Chorionic villus sampling (CVS) is a method that is used to detect chromosomal conditions (e.g. trisomy 21) in the baby. It is carried out if the result of the first trimester screening was abnormal or if a genetic condition is known to run in the family. The examination is performed in or after the 11th week of pregnancy.
During CVS, the doctor inserts a thin needle through the abdominal wall into the placenta and takes a sample of cells, which have the same genetic make-up as the baby. In this way, it is possible to ascertain at an early stage whether the baby has a genetic condition.
Amniocentesis is a method that is used to detect chromosomal conditions (e.g. trisomy 21) in the baby. The test is usually performed in or after the 15th week of pregnancy due to a specific suspicion that the baby has a genetic disorder. Such a suspicion arises when the result of the first trimester screening is abnormal.
In amniocentesis, the doctor takes a sample of amniotic fluid from the amniotic sac. To do this, a thin needle is inserted directly into the amniotic sac through the abdomen and around 10 to 15 ml of amniotic fluid are removed. By using an ultrasound scanner, the doctor is able to monitor the child’s position at all times during the procedure and see exactly where the needle is located. The puncture site closes again immediately and the amniotic fluid is regenerated within a few hours. The amniotic fluid and the cells it contains are then examined in the laboratory.
What prenatal diagnostics cannot do – limits and challenges
Prenatal diagnostic testing can provide a lot of information about the unborn baby’s health. However, the tests do have their limits and involve a number of challenges. These include:
- Inaccurate results: Not all tests are 100% accurate. Sometimes a test will show an abnormality even though the baby is healthy, or it will fail to detect a condition that the baby has. This can create unnecessary concern for the parents or give them a false sense of security.
- Ethical questions: If a test does detect a specific illness or disability in the baby, the parents are faced with some difficult decisions. They might ask themselves questions like «What should we do now?» or «How will life be with our baby?».
- Limited informative value: Some tests only indicate a risk – they do not provide a clear diagnosis. As a result, you will not be able to say with certainty whether your child is ill or not. Furthermore, some diseases cannot be detected with prenatal diagnostics. Some deformities or illnesses can only be diagnosed late in the pregnancy or after the birth.
Prenatal diagnostics – making a well-informed decision
All prenatal tests are voluntary. As parents, you have the right to turn down tests, only take certain tests, or not to be informed of the result. You can also change your decisions at any point during the pregnancy. The decision for or against prenatal diagnostics is a personal and highly significant one. It is therefore important to think about this topic at an early stage and ensure that you are well informed, as this will enable you to make your decision freely and without any pressure.
Take the time you need to find out about prenatal testing and prepare for the consultation with your doctor. There are also a number of independent advice centres that can assist you and provide comprehensive information and support.
-
Information and advice centres
- Profamilia: provides support with questions on sexuality, family planning and partnership
- Sexual Health Switzerland (available in German, French and Italian)
- Association for Holistic Advice and Critical Information on Prenatal Diagnostics (available in German and French)
- Appella: advice centre for questions on contraception, pregnancy, prenatal diagnostics, childbirth, trying for a baby and the menopause (available in German)
-
Checklist: medical consultation on prenatal diagnostics
Prenatal diagnostics: how should I decide?
The following questions can help with making the decision for or against prenatal diagnostics:
- How long does it take to get the result?
- How accurate is the test result?
- What will we do if the finding is abnormal?
- Which diagnoses will we receive with regard to our child during the pregnancy?
- What do we know about children with disabilities?
The decision tree from insieme provides further guidance (available in German and French).
Prenatal testing has delivered an abnormal result – what now?
A test result that indicates an illness or disability in the unborn child can be a very stressful situation for the parents. The receipt of this news often creates a great deal of uncertainty and fear. It is entirely understandable that parents feel overwhelmed and unsure of what to do in such a situation. They are faced with the decision of whether to abort or continue the pregnancy.
It is important to stress that there is no «right» or «wrong» decision here. You should take as much time as you need.
Decision to have the child
What will life be like with a disabled child? Many couples find this hard to imagine. Use this opportunity to obtain all the information you need regarding any medical measures from your doctor. In addition, parent counselling services offer valuable information about life with a child with disabilities. They can also provide contact details of other affected parents.
-
Information and advice centres
- insieme – parents’ associations for people with intellectual disabilities and their family members (available in German and French)
- insieme – parents’ associations for people with trisomy 21 and their family members (available in German)
- Conference of associations of parents of children with disabilities (available in German and French)
Decision to abort the pregnancy
If a test result indicates an illness or disability in the unborn child, the parents also have the option to abort the pregnancy. This is a very difficult and potentially stressful decision. Seek assistance from specialists and accept all the support you are offered before, during and after the termination. There are various services that offer assistance to affected couples.
-
Information and advice centres
- kindsverlust.ch – competence centre for people who have lost a baby during pregnancy, childbirth or infancy (available in German)
- APAC-Suisse – working group abortion and contraception Switzerland (available in German and French)
- Sexual Health Switzerland (available in German, French and Italian)
The CONCORDIA mental health check can offer guidance on coping with the mental burden.Prenatal diagnostics: what does the health insurance pay?
Checked by Pro Juventute!
Experts from our partner Pro Juventute have checked this text for factual accuracy.
