Pre-implantation diagnostics – treatment, effects & risks
Preimplantation diagnosis
Doctors refer to molecular genetic examinations as pre- implantation diagnostics . Research is carried out into hereditary diseases or anomalies in the chromosomes in embryos that are created as part of artificial insemination .
What is preimplantation diagnosis?
Pre-implantation diagnostics ( PGD ) are medical examinations of embryos that are created through artificial insemination. The embryos are only a few days old and are examined before they are transplanted into the female uterus . In this way, it is possible for doctors, among other things, to detect errors in chromosomes that pose a risk of miscarriage or stillbirth.
The parents can then decide whether or not to transplant into the uterus. Preimplantation diagnosis is one of the controversial medical procedures. Although the method has been used since the 1990s, it has only been approved in Germany since 2011.
Function, effect & goals
Preimplantation diagnostics is used to uncover genetic changes that provide indications of serious illnesses in the unborn child. The genetic material of artificially fertilized egg cells is checked for chromosomal disorders and hereditary diseases . However, the prenatal diagnosis method is only carried out in risk groups where there is a suspicion of a genetic disease.
This can be the case, for example, if Huntington ‘s disease has already occurred several times within a family. There is also the possibility that the woman has already had several failed artificial inseminations ( in vitro fertilization ).
However, the results of pre-implantation diagnostics are not always absolutely reliable. In rare cases, incorrect diagnoses are quite conceivable. To confirm the diagnosis, additional prenatal diagnostics (PND) can be performed, such as a chorionic villus biopsy or an amniocentesis . The genetic diseases for which preimplantation diagnosis makes sense include primarily Huntington’s disease, sickle cell anemia , cystic fibrosis , beta – thalassemia and Marfan syndrome .
Other disorders include Patau syndrome (trisomy 13), Edwards syndrome (trisomy 18), monosomy 21 and Duchenne muscular dystrophy . In the meantime, however, PGD is not just limited to detecting around 200 hereditary diseases. It also serves to increase the success rate of artificial insemination and to select the sexes , although there does not necessarily have to be a connection to a disease. In addition, preimplantation diagnostics also identify diseases that can be examined in the context of prenatal diagnostics, but for which no diagnosis is usually made.
Aneuploidy screening is the most common area of application for PGD . This is increasingly used in infertile couples who are older and have had several unsuccessful attempts at in vitro fertilization or miscarriages. As part of the pre-implantation diagnosis, the embryos that are responsible for the problems that arise should be separated out. In this way, the chances of having a healthy child can be increased.
In some countries, the PID is also used to identify so-called rescuer siblings. This refers to embryos that can help older siblings suffering from a serious illness by donating umbilical cord blood or bone marrow . For this purpose, pre-implantation diagnostics select the appropriate tissue characteristics after artificial insemination.
In order for pre-implantation diagnosis to take place, artificial insemination must first take place. This leads to the formation of several embryos. The fertilization of the female egg cells with the man’s sperm takes place outside the body. After the egg cells have been sucked out of the woman’s body, they are developed into embryos in a test tube. Around three days after fertilization, one or two cells can be removed and examined as part of preimplantation diagnostics, for which different techniques are used.
Risks, side effects & dangers
Pre-implantation diagnosis is always associated with the risks that exist with artificial insemination. This major procedure can have side effects such as pain , breathing difficulties , nausea and blood clotting disorders.In addition, one complication must be expected, which occurs more frequently with artificial insemination in connection with PGD than with other procedures. This is Ovarian Hyperstimulation Syndrome (OHSS). It is divided into mild and severe progressive forms. In the severe forms there is sometimes even a risk of death.
Basically, the woman receives numerous hormones during artificial insemination in order to allow the egg cells to mature in the ovaries . In pre-implantation genetic diagnosis, the amount of hormones must be even higher than in simple test-tube fertilization without PGD. However, this means there is a risk of overstimulation of the ovaries, which becomes noticeable through their strong enlargement. Cysts form inside the ovaries and the abdomen increases in size. In some affected women, fluid can also accumulate in the abdominal region. In addition, the blood increases in viscosity, which in turn causes circulatory disorderskidneys . As a result, there is a risk of dangerous renal insufficiency .
Preimplantation diagnosis is a procedure that has been the subject of heated debate around the world for years. The discussions raise fundamental ethical and political questions about the value of life. Critics accuse PID of not accepting social diversity. In addition, the pressure on parents to have healthy children is increasing. The approval of pre-implantation diagnostics in Germany would damage the value system of the Basic Law on the right to dignity. However, the advocates of PGD see the procedure as an opportunity to spare couples and their children serious hereditary diseases.
Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.