Dear future parents
|First of all, let us say that we share in your happiness at becoming parents! The birth of your child will take place in only a few months time. You may feel excited anticipation and ask yourself a question which so many other expectant parents pose, namely whether the offspring to be born will be in good health. From your friends and in the media, you have most probably heard about prenatal examinations for pregnant women and their unborn children.|
It has been long known that the overall statistical risk for a child to develop certain diseases increases with the mothers age. However, this is by far not indicative of the individual risk, i.e. your personal risk, let alone of an actual disease of your child. By the same token, many other children and also younger mothers may be affected just the same because a major share of diseases found in children occurs irrespective of the mothers age.
|A new, easy and complication-free examination during the first 11 to 14 weeks of early pregnancy, performed in conjunction with an analysis of a maternal blood sample, offers quantified risk assessment for many diseases that a child may develop.|
|This is the so-called first-trimester screening. It consists of a simple ultrasound test to assess the so-called "nuchal translucency thickness" of the fetus, and it includes the collection of a maternal blood sample. It is important to know the following:|
|Nuchal translucency thickness (also called NT or "neck fold thickness") is determined by performing an ultrasound scan of the fetus`s neck. Low nuchal translucency values are categorised as normal. However, as nuchal translucency increases, so does the risk of the fetus to develop a disease. The examination requires a high-resolution ultrasound device and an experienced examiner. The FETAL MEDICINE FOUNDATION Germany (FMF-Germany) trains colleagues in this method. You can recognise these physicians by their Certificate of Competence issued by the FMF-Germany which must be re-obtained every year. When measuring nuchal translucency, the size and the structural health of your child are also examined. In parallel, two pregnancy hormones (free beta-hCG and PAPP-A) are analysed from the mother`s blood sample. Certain changes in their concentration, evaluated in relation to a statistically determined normal level of concentration (the so-called median value), must be interpreted as an indication of chromosomal aberrations and further diseases (e.g. heart defects). Based on these biochemical results and on the ultrasound data, an overall risk is determined with consideration to your individual maternal age risk. This individual overall risk of your child is assessed by means of the most exact method currently available for risk evaluation in early pregnancy.|
|What does the test result mean?|
|This risk evaluation test statistically quantifies your individual risk. Some five percent of all examinations performed may indicate a suspicious result. The test cannot make a definite diagnosis, however, up to 90 percent of all trisomy 21 pregnancies can be allocated to a risk group. A suspicious test result is not necessarily indicative of a pregnancy with chromosomal aberration. It only states that this pregnancy must be assigned to a risk group. In this case, specific follow-up examinations may be performed, e.g. amniocentesis, chorionic villus sampling and subsequent chromosome analysis, which will allow either the definite exclusion or an accurate diagnosis of chromosomal aberration.|
|By the same token, however, an unsuspicious result does not constitute an absolute guarantee that the child to be born will be free of chromosomal abnormalities. Only direct chromosome analysis can provide the certainty of definite exclusion.|
|However, the invasive intervention it requires poses more complications than the described risk evaluation test and always involves a risk of miscarriage, however small this may be. This new risk evaluation test (the so-called first-trimester screening) therefore aims at reducing further invasive examinations to the indispensable minimum - in order to keep any risk to your pregnancy as low as possible - thanks to a reliable, quality-assured risk assessment method.|
|What to do in case of an increased risk?|
|If an increased risk has been identified, your gynaecologist or a geneticist should provide you with extensive counselling in order to discuss options for further diagnostic testing. Following this careful consultation, a prenatal diagnostic procedure may be performed which will yield an accurate result regarding chromosomal aberration. In order to shorten the waiting period, which is usually felt to be stressful, a rapid prenatal test (FISH test) can be carried out in many cases which will provide a result within only one or two days.
In the vast majority of cases, the test result is unsuspicious. However, in the case of an increased nuchal translucency with at the same time unsuspicious results of chromosome analysis, a further ultrasound examination should be conducted at about the 20th week of pregnancy so that heart defects and other non-chromosomal anomalies can be excluded.
If you have further questions, your gynaecologist will be available to answer them.
|With kind regards|
Tel.: +49 (0) 5506 - 999 760