Preimplantation testing – A method for reducing the risk of miscarriages

The development of modern medicine has revolutionized reproductive procedures, particularly artificial insemination. During this process, couples who face difficulties with natural conception gain access to new opportunities that allow them to have children. The in vitro fertilization program, as one of the most widespread methods, offers solutions not only for couples struggling with infertility but also increasingly provides options for screening genetic disorders. Professionals, such as Dr. Attila Vereczkey, the medical director of the Versys Clinics Human Reproductive Institute, continuously work to provide patients with the highest level of professional support alongside the most advanced procedures.

Concerns About Birth Defects

In the case of children conceived through the IVF program, the question arises whether there is an increased occurrence of birth defects. According to available data, the rate of abnormalities in IVF babies is similar to that of children conceived naturally, ranging between 1-1.5%. However, for certain procedures, such as intracytoplasmic sperm injection, the chance of defects may increase to 1.5-2%. This technique is primarily used in cases of severe male infertility when sperm quality is poor, or if only one or two sperm can be extracted. There are various theories regarding the causes of this increase, but determining the exact reasons is not always straightforward.

Screening for Genetic Disorders

One of the most effective methods for screening genetic disorders is prenatal genetic testing. This method is conducted at a certain stage of pregnancy, usually around the 10-12th or 16-18th week. The procedure distinguishes between two main groups: invasive and non-invasive procedures.

Invasive procedures involve sampling from the placenta or amniotic fluid, which requires surgical intervention. This method allows for the most accurate determination of the fetus’s genetic status since it provides direct access to fetal cells. During tests, it can be determined with 95-99% accuracy whether the fetus is affected by any genetic disorder.

In contrast, non-invasive procedures obtain information about fetal DNA from maternal blood. This test is performed through venous blood sampling and can also yield highly accurate results, achieving a reliability of 95-98%. However, it is important to note that these tests do not always provide definitive answers, so in the case of unfavorable results, invasive procedures may be necessary to confirm the diagnosis.

Non-invasive tests include fetal ultrasound and blood tests, during which the expectant mother can decide on further steps based on the results obtained.

Preimplantation Genetic Screening

Preimplantation genetic testing, including PGD and PGS methods, allows for the examination of the fertilized egg before implantation. This process enables couples to decide whether to implant the embryo based on the results of the tests. The PGD procedure is specifically recommended for couples at risk of genetic disorders.

During PGS, the fetus’s chromosome composition is examined to identify numerical or structural abnormalities. The most common abnormality is trisomy 16, which can result in miscarriage or stillbirth. With the help of preimplantation genetic screening, couples can avoid the birth of a child with a genetic disorder.

In Hungary, the application of preimplantation genetic testing is legally regulated, but the popularity and availability of the procedure vary. The Versys Clinics Human Reproductive Institute, which I lead, has applied the aCGH method, but recently legal issues have arisen that restrict the performance of these tests. Currently, not all institutions in the Hungarian healthcare system perform preimplantation genetic screening, so it is important for couples to be informed about their options and the available procedures.

The advancement of reproductive technology may offer further opportunities for couples in the future to have healthy children while minimizing the risk of genetic disorders.