Is my baby okay? Will it be born healthy? These questions are asked by many people who are pregnant. In fact, today there are many procedures that can be used to check whether there are indications of certain diseases or fetal malformations. You usually have to pay for some of these prenatal examinations yourself. Some gynaecologists recommend that older pregnant people over the age of 35 should have such examinations. It may also be that your doctor finds certain abnormalities during the three regular standard ultrasound examinations and advises you to have further examinations. Below you will find descriptions of the most common methods of prenatal testing. Before any of these tests, you must receive medical clearance and genetic counselling in accordance with the Genetic Diagnostics Act. Doctors must have special, additional training for this. It is very important that you take time after the consultation to think about it and inform yourself well.
First trimester screening is a combination of different examination procedures that are usually used between the 11th and 14th week of pregnancy to determine the risk of certain chromosomal disorders. Doctors measure the embryo or fetus with a high-resolution ultrasound device. An important part of first trimester screening is the nuchal scan. When measuring, the thickness of the nuchal transparency is compared to the length of thefrom the top of the head to the rump. Values between 1 and 2.5 millimetres are considered normal. If the fetal neck fold is 3 millimetres or more, both the length of the nasal bone and the blood flow in the heart and in the large blood vessels are also checked. In addition, ultrasounds can already exclude some fetal malformations and detect growth disorders. Indications of the increased risk of developing can also be detected and allow for early treatment. In addition, a blood test will be done to check several protein and hormone levels in your blood. From the results of these tests and other data, such as your age, your ethnicity and the exact week of pregnancy, a computer programme calculates the probability that your child has certain chromosomal defects. However, diseases cannot be detected directly and diagnosed with this method.
Amniocentesis is a surgical procedure that can directly and reliably detect diseases and abnormalities in the genetic material of a fetus. It can be done from the 15th week of pregnancy on. To do this, the doctor inserts a fine needle through the abdominal wall and the uterine wall into the amniotic sac and removes some amniotic fluid. The infantile cells floating in it are examined in the laboratory for defects and deviations. The result of the rapid test are available after 2 days. However, a final result will only be available after two to three weeks. The wait can be very stressful for expectant parents. In addition, amniocentesis is not without danger. It can lead to contractions, leakage of amniotic fluid and, in the worst case, miscarriage in one to two out of 1000 cases. The likelihood of these problems also depends on the experience of the examiner.
Chorionic villus sampling is also a surgical procedure. This allows the fetus to be examined for genetic disorders in the womb from the 11th week of pregnancy on. The doctor removes a tiny piece of tissue from the chorionic villi either through the vagina or through the abdominal wall using a hollow needle. This is what theis called at this stage. The cells contained in the tissue are then examined in the laboratory for deviations in the genetic material. After a few days the results are available. Chorionic villus sampling is usually performed without anaesthesia. A stay in hospital is not necessary for this. However, you should take it easy for the first few days after the procedure. Like any procedure, chorionic villus sampling carries risks. Infection, vascular injury, and preterm labour may occur. Chorionic villus sampling requires experience and skill. Physicians who perform such examinations should ideally have a specialisation in obstetrics and perinatal medicine and sufficient practical experience in these procedures.
There are tests that can be done to find out if your baby has a defect in its genetic makeup by taking a blood sample from you. They are called noninvasive prenatal tests, or NIPT for short, and have brand names such as PraenaTest, fetalis, Harmony and Panorama. These tests can be used to look for the most common types of chromosomal abnormalities. These are Down syndrome (also called ‘trisomy 21’), Edwards syndrome (also called ‘trisomy 18’) and Patau syndrome (also called ‘trisomy 13’). In addition, changes in the sex chromosomes X and Y are checked. After the blood sample has been taken, it takes up to seven working days for the result to be available. The reliability of the tests is considered high, but if the result is ‘positive’, an amniocentesis should still follow to confirm the findings. Prices vary depending on the provider and the scope of the test. You can either have a single chromosomal disorder checked or several chromosomal disorders at once.