The most recent study results published in the Fertility and Sterility bring information which is important for infertile couples. According to the reports, performing the specialised pre-implantation diagnosis within the IVF programme can increase the chance of getting pregnant even twice. The project was carried out by a team of researchers from infertility treatment centres in Poland and in the UK. The analysis covered the effects of treatment in nearly 100 female patients from the study and the control group.
Preimplantation genetic diagnosis – PGD – is a vital component of reproductive medicine. It enables the detection of abnormalities in the genotype of the embryo before its transfer to the uterus. It is estimated that 50% to 90% of embryos at the cleavage stage is genetically abnormal – says Professor Krzysztof Łukaszuk, MD, the initiator of the project, from the INVICTA Fertility Clinic. According to experts, the early detection of defects and selection of healthy embryos increases significantly the chances of obtaining the pregnancy and its normal development. Patients can also avoid difficult situations associated with miscarriage or the loss of a child.
The genetic studies were carried out by scientists on the basis of the so-called next generation sequencing – NGS. This is currently the most modern method, considered the model for all others. It enables obtaining the huge amount of information, particularly as regards changes in chromosomes and mutations in single genes –stresses Sebastian Pukszta, MD, Deputy Head of the INVICTA Medical Laboratories and co-author of the study
In the framework of the project, PGD tests were carried for aneuploidies, i.e. disorders in the number of chromosomes. They represent the most common cause of failure of embryo implantation and of miscarriages. The abnormalities of this type result in the occurrence of serious defect syndromes in live-born children, such as Down syndrome, Edwards syndrome, Klinefelter’s syndrome, Patau syndrome or Turner syndrome. A total of 252 embryos obtained from 45 patients were subjected to genetic diagnosis. The control group consisted of 53 women subjected to the treatment without the use of genetic diagnosis. In order to increase the reliability of the analysis, all patients had similar causes of infertility, hormone levels and underwent already at least 2 unsuccessful attempts at in vitro fertilisation in the past.
Our most important observation concerned the increase in the percentage of pregnancies after PGD diagnosis. It amounted to nearly 85%. In patients where the genetic testing of embryos was not carried out, the pregnancy was confirmed in 41.5% of cases – Professor Łukaszuk from INVICTA summarises the results. Furthermore, the analysis confirmed the 30%increase in the proportion of implanted embryos. According to the researchers, the completed project – although it requires the extension of the study group and continuation of work – is so far the largest study with the NGS PGD carried out for aneuploidies and the milestone in terms of a better understanding of the method. The results obtained in terms of a significant increase in implantation and pregnancy rates seem to be very interesting in the context of increasing the effectiveness of treatment of infertile couples. The use of the next generation sequencing in preimplantation diagnosis provides a hitherto unattainable sensitivity and credibility. With thousands of repetitions we can obtain huge amount of information. This in turn allows for the identification of virtually every known genetic change – adds Doctor Pukszta.
The indications for genetic testing of embryos include the infertility of unknown origin, woman’s age over 35 years, confirmed genetic burden, recurrent pregnancy loss, as well as earlier failed in vitro programmes. The INVICTA Fertility Clinics are the forerunner of preimplantation diagnosis in Poland (first performed in 2005). Currently, the centre is ranked 6th in the world in terms of number of performed PGD tests.