Analytical methods

Ultrasound test

The technical term for ultrasound is sonography (abbreviation: Sono). It artificially generates sound waves of a certain frequency that the human ear cannot hear or feel. These are reflected by the body of the pregnant woman and the child and the echo waves are converted into an image.

General prenatal care includes three ultrasound tests around the 10th, 20th and 30th week of pregnancy . These three ultrasound tests are not regarded as targeted malformation diagnostics in the sense of the German Genetic Diagnostics Act. Therefore neither the written declaration of consent nor the genetic counselling and the reflection period, which are prescribed for all other or further special tests, are statutory for them.

Basic ultrasound and advanced basic ultrasound

In the 20th week, you can choose between the basic and the advanced basic ultrasound (or decide not to get any tests done altogether).  Before the first ultrasound test, your doctor must talk to you about the procedure.

Basic ultrasound can be used to assess whether the unborn child has developed in line with the due course of time. To determine this, the doctor measures the head, stomach and a thigh or upper arm. In addition, the placenta, the amount of amniotic fluid and the heartbeat are also evaluated.

In the advanced basic ultrasound, the head, brain, neck, back, abdominal wall, heart, stomach and urinary bladder are also examined more closely. The doctor must prove a special qualification for its implementation.

What can be determined?

In the first ultrasound examination, the age of the pregnancy, the implantation spot in the uterus and the heart beats of the child are determined in particular. Multiple pregnancies can also be detected. If ectopic pregnancy is suspected and bleeding occurs during early pregnancy, the ultrasound test can clarify the situation.

During the second ultrasound test around the 20th week, the growth and development of the foetus are assessed and special attention is paid to the development of the organs and physical structures. Here, malformations such as heart defects, kidney malformations, neural tube defects (open back) or indications of chromosomal defects can be found out.

Also during the third test around the 30th week, the growth and development of the child are monitored. The position of the placenta is determined, the position of the child and the amount of amniotic fluid are assessed. For instance, during these tests, deficiency in growth or indications of gestational diabetes can be determined and treated accordingly.

What should I bear in mind?

Ultrasound is done so that the health of the pregnant woman and the child is monitored. On the other hand, the tests help detect malformations, if any. Many couples are reassured and happy when everything is fine with ultrasound. Unfortunately, especially with ultrasound, small deviations from the "normal" are found more often than not, which can be very unsettling even though they turn out to be harmless later on. If there are abnormal findings, further tests are usually recommended.

Do not be afraid to talk to your doctor about this before carrying out any tests. As a matter of principle, the pregnant woman is also at liberty “not to know”.

Risks

According to recent findings, there are no known risks for mother and child while undergoing routine ultrasound tests.

Costs

The costs for these tests are covered by the statutory health insurance companies; and are considered to be a benefit within the framework of prenatal care. Since the introduction of so-called IGeL services (individual health services), some practices advise further tests between the three routine ultrasound tests, which are not covered in any insurance. Normally, the three scheduled tests are sufficient.

First trimester test

First trimester means "first third (of pregnancy)". The first trimester test is also called nuchal translucency screening or first trimester screening.

How is the test performed?

Between the 11th and 14th week of pregnancy, the pregnant woman’s blood sample is taken in the first week of pregnancy and an ultrasound test is carried out at the same time.

By measuring the Nuchal translucency and, if necessary, with the help of assessment of the child's nasal bone, maternal blood test results, as well as the maternal age and the week of pregnancy, a statistical value-at-risk for a child with Down's syndrome can be calculated with the help of a computer program.

For a certain level of value-at-risk, it is recommended to carry out further tests such as Chorionic villus sampling or Amniotic fluid test (Amniocentesis).

What can be determined?

The first-trimester test helps determine a purely statistical value-at-risk from several resultant values for the certain numerical chromosome disorders present in the child; although this is not a diagnosis.

Women over the age of 35 can refrain from amniotic fluid test based on these assessments, as this choice offers a lower calculated risk compared to the age risk at hand otherwise. Women under the age of 35 may be at increased risk for the presence of Down syndrome for instance, without resorting to invasive tests.

What should I bear in mind?

In Germany, there are no standardised nationwide guidelines for conducting these tests and hence these tests are handled very differently. The results may vary depending on the computer program used. DEGUM, the German Society for Ultrasound in Medicine, has developed quality standards for the first trimester test. In practices or centres that are certified according to DEGUM levels II and III, you can assume a high detection rate for chromosomal defects or early detectable malformations.

False positive results (i.e. an increased value-at-risk is calculated for a healthy child) occur in two to eight percent of pregnant women under 35 years of age subject to their age. A result in the “abnormal” range can bring great upheaval during pregnancy.

Prenatal blood test

In the prenatal blood test, a blood sample is taken from the pregnant woman. In the laboratory, the DNA components of chromosomes 21, 18 and 13 detectable in the blood are counted in a fully automatic high-tech laboratory device. This allows findings related to trisomy 21, 18 and 13 as well as other numerical deviations of the sex chromosomes such as Turner's syndrome to be obtained.

The test can be carried out from the 9th week of pregnancy . It takes 4-6 working days until you can get your hands on the results. Any abnormal findings are confirmed by an amniotic fluid test.

Since the test falls under the Genetic Diagnostics Act, only prenatal physicians, human geneticists or gynaecologists with the qualification for specialist genetic counselling may advise this test after detailed counselling.

How accurate is the blood test

Studies have shown: Of 753 pregnant women with increased risk, the test detected all women whose children had trisomy 21. However, it should also be duly noted that it also included two women whose child did not have trisomy 21. However, there is not yet enough data to really say how reliable it is in normal application. Further studies are underway.

Costs

The cost of the prenatal blood test depends on the chromosome distribution to be examined. The costs for trisomy21 only cost about 200 €, for trisomy13, 18 and 21 or maldistribution of the sex chromosomes, the costs are 300 and 400 € respectively.

Currently, the prenatal blood test is an individual health service i.e. it has to be paid by the patient. In the past, however, some health insurance companies have already covered the costs of the test in individual cases.

Amniocentesis or amniotic fluid test

Amniocentesis is performed on an outpatient basis in a gynaecological practice, in a special practice or in a clinic. A thin hollow needle is inserted into the uterus through the woman's abdominal wall under ultrasound vision. 10 to 15 ml of amniotic fluid is removed from the amniotic cavity. The position of the needle is constantly monitored by means of an ultrasound image. The puncture is usually performed from the 15th week of pregnancy.

A so-called early amniotic prolapse in the 12th - 14th week of pregnancy can also be carried out, but it is usually associated with an increased rate of miscarriages and unclear findings.

What should I bear in mind?

You may experience a brief moment of pain when piercing the abdominal wall.

The results of the chromosome test are only available after two to three weeks, because cell cultures must first be created before chromosome preparations can be made and evaluated. The duration of the DNA analysis depends on the disease to be tested. The protein and enzyme values as well as the infection diagnosis are usually available within one week.

Amniocentesis

Amniocentesis or amniotic fluid test

Amniocentesis is performed on an outpatient basis in a gynaecological practice, in a special practice or in a clinic. A thin hollow needle is inserted into the uterus through the woman's abdominal wall under ultrasound vision. 10 to 15 ml of amniotic fluid is removed from the amniotic cavity. The position of the needle is constantly monitored by means of an ultrasound image. The puncture is usually performed from the 15th week of pregnancy.

A so-called early amniotic prolapse in the 12th - 14th week of pregnancy can also be carried out, but it is usually associated with an increased rate of miscarriages and unclear findings.

What should I bear in mind?

You may experience a brief moment of pain when piercing the abdominal wall.

The results of the chromosome test are only available after two to three weeks, because cell cultures must first be created before chromosome preparations can be made and evaluated. The duration of the DNA analysis depends on the disease to be tested. The protein and enzyme values as well as the infection diagnosis are usually available within one week.

Rapid test (FISH test)

A 24-hour rapid test can also be carried out on the amniotic fluid cells (fluorescence in situ hybridisation - FISH) after an amniotic fluid test.
The procedure cannot replace the differentiated chromosome analysis, since it is associated with a method-inherent uncertainty factor. In selected individual cases, the rapid test can be carried out parallel to chromosome analysis in order to obtain the quickest possible clarification for specific suspected diagnoses. The costs are only covered by the statutory health insurance in special situations.

Risks of amniocentesis

The punctures in the skin, abdominal wall and uterus close immediately after the puncture. In very rare cases, amniotic fluid may be drained through the vagina and/or bleeding may occur in the placenta. Temporary contractions can also occur. On the other hand, injuries to the child due to the needle are extremely rare.

After an amniotic fluid puncture, miscarriages occur in 0.11 to 1 percent of cases. Above all, the risk of complications depends on the competence and experience of the doctor performing the procedure.

In rare cases, the procedure needs to be repeated because no amniotic fluid could be removed or the test results are not clear.

Costs

The costs for amniocentesis are covered by the statutory health insurance. As a rule, private insurance companies also cover the costs, if the tests and interventions are medically justified.