Preimplantation genetic testing: Science at… | Prague Fertility Centre

Preimplantation genetic testing: Science at your service 



Preimplantation genetic testing (PGT) is a revolutionary method that increases the chances of a healthy pregnancy and eliminates the transmission of genetic diseases. This article discusses the benefits of PGT, presents interesting data and reveals the ethical aspect associated with this innovative testing technique that enriches the assisted reproductive process.

Preimplantation genetic testing (PGT) is a revolutionary method that allows the genetic testing of an embryo before its transfer into the uterus. This advanced approach to assisted reproductive technology was first used in 1990, and more than thirty years later, its goal has not changed: to shorten the time to successful pregnancy, eliminate traumatic pregnancy losses, and maximize the chances of a healthy baby. In 2023, 217 PGT cycles were performed at our Prague clinic, which represents a significant part of the total of 1 052 cycles of IVF treatment.

One of the most common types of preimplantation genetic testing is PGT‑A, which accounted for 90 % of all cycles performed. This screening test is used to identify chromosomal abnormalities in embryos, which is particularly important in women over 35 years of age or in couples with a history of recurrent miscarriages. Other types of PGT are PGT‑M and PGT-SR, which focus on ruling out specific genetic defects and structural chromosomal rearrangements that may run in families.

Successful cases from clinical practice illustrate the importance of PGT for couples facing genetic problems. The first example is a 43-year-old female patient who repeatedly miscarried in the first trimester. Although her ovarian function was very good, genetic testing revealed new mutations of oocyte origin. After three cycles of stimulation and genetic screening, one embryo was healthy and after transfer to the uterus, a healthy baby boy was born. Another successful example is a couple where both parents were carriers of phenylketonuria. With PGT‑M, three healthy embryos were selected from five prepared blastocysts and one of the embryos was successfully transferred, resulting in the birth of a healthy son without genetic disease.

According to the leading IVF specialist Dr. Lucie Švabíková, Ph.D., the use of PGT requires a medical indication and a thorough genetic examination of both partners in every case. PGT is considered an invasive method and should only be performed in cases where it can actually increase the chances of a healthy pregnancy and childbirth. It is only legal in the Czech Republic under certain conditions, which include a woman’s age over 35, repeated miscarriages, failed treatments or genetic indications based on the pathology of the parents’ genetic testing.

Preimplantation genetic testing (PGT) is a complex and expensive process, costing hundreds to thousands of euros. Although the investment is significant, the results can have a major impact on the quality of life of both parents and their children. With PGT, it is possible to break the chain of serious genetic diseases in affected families and increase the chances of a healthy pregnancy and the birth of a healthy child. In this way, assisted reproduction becomes a hope for many couples who would otherwise face difficult genetic challenges.

[1] Handyside AH, Kontogianni EH, Hardy K, Winston RM. Pregnancies from biopsied human preimplantation embryos sexed by Y‑specific DNA amplification. Nature. 1990 Apr 19;344(6 268):768 – 70. doi: 10.1 038/3 44768a0. PMID: 2 330030.