During this webinar, Dr Manuel Izquierdo, Director of Medical Quality & Consultant Gynaecologist at IVF Life Madrid, discussed the indications for Pre-implantation Genetic Testing (PGT-A) and shared some of his real-life patient cases, showing all the steps that allowed the couples to achieve pregnancy.
Chromosomes are essential structures containing DNA information that determine our genetic makeup. They are arranged in pairs, with 22 pairs known as autosomes and one pair determining the sexual characteristics (X and Y chromosomes). During fertilization, the egg and sperm each contribute half of the chromosomes, forming a complete set in the embryo.
Errors can occur during the division of chromosomes in gametes, resulting in abnormal karyotypes. These abnormalities may lead to conditions like Turner Syndrome (X chromosome deficiency) or Down Syndrome (extra chromosome 21). Many chromosomal abnormalities are not compatible with life, leading to failed implantation or early miscarriages.
Prevalence of Aneuploid Embryos and Maternal Age
A significant percentage of embryos are found to be aneuploid, with around 30% detected in women under 36 years old undergoing IVF. The rate of aneuploidy increases with maternal age, with 90% of day 5 blastocysts being aneuploid in women around 44 years old.
The prevalence of aneuploid embryos negatively affects pregnancy rates in older women. Patients may struggle to conceive, even with regular periods and normal sperm parameters, due to chromosomal abnormalities in their eggs.
The Role of PGT-A in improving pregnancy chances
PGT-A (Preimplantation Genetic Testing for Aneuploidy) is a valuable tool to identify chromosomally normal embryos for transfer. In cases where a woman has a good ovarian reserve and produces multiple embryos, PGT-A can increase the chances of identifying a euploid embryo that has the potential to lead to a successful pregnancy.
As women age, the quality of their eggs and embryos is affected, leading to an increased likelihood of chromosomal abnormalities. PGT-A can be a helpful option for those undergoing fertility treatments, as it allows the identification of chromosomally normal embryos, improving the chances of a successful pregnancy. Though pregnancy rates may decrease with age, the presence of euploid embryos offers hope and the possibility of starting a family.
Defining Repeated Implantation Failure
Dr Izquierdo addressed the concept of repeated implantation failure, where embryos fail to implant after several attempts. While embryo quality and morphological grading are considered, they do not provide perfect information about the embryos’ chromosomal constitution. Hence, it is vital to define repeated implantation failure carefully and consider chromosomal analysis as an option to improve success rates in such cases.
The biopsy procedure for chromosomal analysis is a safe technique. Dr Izquierdo explained that the process is minimally invasive and does not pose a significant risk to the embryos. Additionally, the embryos are frozen while awaiting the analysis results, ensuring their well-being during the process.
In conclusion, factors such as age, previous attempts, and medical history should be carefully evaluated to determine if this option is suitable for each patient. Ultimately, chromosomal analysis can significantly improve the chances of successful implantation, pregnancy, and the birth of healthy babies, making it a valuable tool in fertility treatment.