Prenatal Diagnostics

How is "risk" determined?

The methods of prenatal tests were developed especially for couples with an above-average risk for a child with a certain disease or impairment.

Among other things, an above-average risk exists, if

• the pregnant woman, her partner or relatives are affected by a hereditary disease or disability
• there is a history of an already born child having a hereditary disease or disability
• the pregnant woman has been treated before or during pregnancy with certain medication or radiotherapy
• the pregnant woman is over 35 years old and thus there is a slightly increased risk of chromosomal defects in the child.

The developments in the previous years have led to a strong growth in the number of prenatal tests carried out amongst women and couples even without special risk.

Genetic risk from the age of 35?

Every pregnancy can lead to a random maldistribution of chromosomes. This risk increases with the age of the pregnant woman and is very low in younger women.

In accordance with the maternity guidelines, women of and above the age of 35 years are advised to seek consultation regarding the prenatal tests for Amniocentesis or Chorionic villus sampling and can have them carried out upon request.

Although, this does not mean that these women suddenly have a much higher risk than the women of or above 34 years of age. The so-called "age risk" from the age of 35 results from a purely statistical analysis between the risk of miscarriage due to amniocentesis and the risk of chromosomal maldistribution.

Example of Down syndrome

The probability of having a child with Down syndrome depends on the age of the pregnant woman:

The number of children with Down syndrome per 1,000 pregnant women is as follows:

• 30 years: 1
• 35 years: 3
• 40 years: 10
• 45 years: 40

According to recent findings, the age of the father does not play any significant role in determination of risk factor.
If a woman has already given birth to a child with a numerical chromosomal disorder (e.g. Down syndrome), the risk of recurrence increases by one percent in every age group.

Also for women over 35 years of age, there is no obligation to have the advised prenatal tests carried out.

The Gene Diagnostics Act (GenDG)

Since 2010, the framework conditions for prenatal tests that can determine hereditary diseases or health disorders of the embryo or foetus have been stipulated in the Genetic Diagnostics Act.

A prenatal test may not be carried out without comprehensive information and your written consent.

You can revoke your consent at any time. You are also at liberty to exercise your right not to know.

Genetic counselling

Before and after a prenatal test, genetic counselling is statutory.

In addition to the medical facts, the counselling also addresses the psychological and social issues that may arise during the test. In addition, you must also be recommended further options of assistance and support to help you cope with psychological stress.

There must be a reasonable time gap for reflection between the genetic consultation with the doctor and the conduction of the tests.  The examining doctor can carry out the consultation himself or refer you to a doctor of human genetics.

These counselling services are optional for you. If you wish to not have them carried out, the doctor will have you confirm this in writing, as he/she is obligated to draw your attention to these consultation offers. However, you are also at liberty not to know, and you can exercise this right at any time.
The tests within the framework of general prenatal care are not affected by this. The usual three ultrasound tests are not considered prenatal tests within the meaning of the law.

Genetic tests may only be carried out for medical purposes and you may also have only those characteristics examined, which impair the health of the child.

Genetic tests for the sole purpose of sex determination or for diseases that occur only after the age of 18 may not be carried out.

What genetic tests can be carried out?

Genetic tests may only be carried out for medical purposes and you may also have only those characteristics examined, which impair the health of the child.

Genetic tests for the sole purpose of sex determination or for diseases that occur only after the age of 18 may not be carried out.

Psychosocial counselling

Psychosocial counselling is a form of counselling that aims at finding room for one's own fears and feelings in addition to valuable specialist information. Don’t let the term "psychosocial" confuse you, this counselling has nothing to do with psychotherapy or anything alike.

Psychosocial counselling can also mean long-term support for a couple or a woman, and is therefore very different from a visit to the doctor.

In the context of prenatal tests, this counselling can be done BEFORE or AFTER a test and also WHILE WAITING for the result of a TEST.

Before a prenatal examination

Before carrying out any prenatal test, it makes sense to carefully consider the advantages and disadvantages of such a test and the reasons for having it carried out. Many women think that prenatal tests are part of pregnancy or that the more tests they perform, the healthier their child will be.

Here are some things you might want to consider

• What exactly do I want to know?
• Can this test provide me with this knowledge?
• What can the test not do?
• What risk am I prepared to take during the test (e.g. miscarriage)?
• What would I/would we do, if something abnormal was discovered during the test?

After an abnormal finding has been found

• What happens next?
• Should further tests be carried out?
• To what extent is your child affected?
• What therapies are available?

If you wish to continue your pregnancy after an abnormal finding

• What could a life with a handicapped child look like?
• What aids are available for your family?
• Who can accompany or support you?

If you have decided to have an abortion or would like to find out more about the possibility of an abortion

• How is an abortion performed?
• How can you say goodbye?
• Who can be there for you in your grief?

Psychosocial counselling does not replace the legally prescribed genetic counselling by the doctor.

Before pregnancy

Human genetic counselling can be useful before pregnancy, if a hereditary disease is known in the woman's or partner's family or if there is a history of an already born child having a hereditary disease. In human genetic counselling, it can be clarified whether the disease can be examined prenatally and how high the risk is for the expected child.

Human genetic counselling/examination can also be useful for women who have already suffered three or more miscarriages.

Women who have undergone chemotherapy, who have been particularly exposed to radiation during or before pregnancy, or who have had to take medication that is harmful to the child, can further clarify the potential risk for the existing pregnancy in this consultation.

During pregnancy

If an abnormal genetic finding has been found after prenatal examinations, you can be referred to a human genetics doctor for further genetic counselling.

Further links

German Society for Human Genetics: Addresses of Human Genetic Counselling Centres and Specialists

Verein psychosoziale Aspekte der Humangenetik e.V. (Society for Psychosocial Aspects of Human Genetics)

A basic distinction is made between "non-invasive" prenatal tests and "invasive" tests.

"Invasive" means "penetrating the body".

Non-invasive tests have no health risk, while invasive tests are associated with the risk of miscarriage. Depending on the type of diagnosis, the rate of miscarriage is indicated to be 0.5-1.5 percent and the experience of the attending physician always plays a crucial role.

Here, we have compiled an overview of all analytical methods for you.