Funding: The study is funded by an educational grant from Ferring and sponsored by King’s College London
Even with increasing advances in medical technology, the success rate following IVF treatment remains low overall and even lower in women aged 35 years or over. The main reason for the lower success rates is often the poor quality of the embryos containing incorrect amounts of hereditary genetic material.
The genetic material of an embryo is known as DNA, or deoxyribonucleic acid. DNA provides important instructions for the human body and is tightly wound and compacted in structures called chromosomes, which are found in cells within our body and within cells in an embryo. Typically, healthy people have 23 pairs of chromosomes in each cell (46 in total). Research has shown that many embryos have an incorrect number of chromosomes in their cells. The older a woman gets, the higher the chance of her eggs being abnormal, leading to embryos with incorrect chromosome numbers. If a chromosome is lost, or one of them is duplicated, the genetic instructions no longer make sense and the embryo is unable to form a healthy baby. For this reason, most abnormal embryos fail to implant in the uterus or miscarry during pregnancy.
Because of the increased chances of abnormal embryos with increasing age, Pre-implantation Genetic Testing for Aneuploidies (PGT-A), previously known as Pre-implantation Genetic Screening (PGS), can be used as a test alongside IVF. This uses a technology known as Next Generation Sequencing (NGS), a sophisticated method that relies on molecular techniques and advanced computers to determine the likelihood of chromosomal errors within the embryo.
Although it’s not a guarantee of a pregnancy, the above has been suggested as an additional tool in selecting a chromosomally normal embryo for transfer. This may increase the chance of a healthy on-going pregnancy. The belief is that by providing PGT-A and excluding the abnormal embryos, PGT-A will help to prevent the transfer of abnormal embryos which would end up not implanting, miscarrying or resulting in the birth of a child affected by an abnormal number of chromosomes.
However, the use of PGT-A with NGS in IVF has only been studied a few times and, for this reason, further research is needed in this area in order to understand its potential benefits and drawbacks. This research project compares performing PGT-A versus no PGT-A and aims to address the best way of delivering IVF treatment in terms of effectiveness, safety and cost, to our patients. We aim to use the results of this pilot project to plan a bigger study in the future.