PRE-IMPLANTATION GENETIC TESTING HELPS BOOST IVF SUCCESS RATES
Every IVF attempt starts with an embryo – the beginning of a baby. However, if repeated efforts to conceive have led to failure, In-Vitro Fertilization (IVF) experts suggest further investigations through a variety of tests to increase chances of success.
Chromosomal abnormalities with the embryo are one of the major reasons for recurrent implantation failure, resulting in more than two-thirds of all unsuccessful implantations. Parental age is one of the major risk factors for having embryos affected by chromosomal abnormalities. The risk of a failed cycle due to genetic problems with a mother aged above 35 is much higher than a mother in her 20s. However, Pre-implantation Genetic Testing (PGT) is a test that can check an embryo for chromosomal defects beforehand, thus resulting in a healthy embryo and further a healthy pregnancy.
Pre-implantation Genetic Testing (PGT) is done to screen the number of chromosomes in the embryos, obtained by In-Vitro Fertilization (IVF) or Intra-Cytoplasmic Sperm Injection (ICSI) prior to the transfer of the embryos into the uterus of the woman. The test identifies chromosomal content of the embryos so that only those with normal chromosomes are transferred. This dramatically improves IVF success rates.
Dr. Francisco Ruiz, Medical Director, IVI Fertility, Muscat, says, “Embryo quality is the strongest predictor of implantation and PGT is the best genetic test to detect any chromosomal abnormalities in the embryo. We are extremely successful with cases where PGT is carried out. The screening is done on cells from the embryo and the procedure involves two steps—opening of the external layer of the embryo (zona pellucida) and removal of the cells. The best moment to perform the biopsy is on day five. A blastocyst, a five-day-old embryo has several hundred cells, so few cells can be safely removed during the biopsy and the results are more accurate. I highly recommend PGT in cases where the woman has a history of recurrent miscarriages, recurrent implantation failure, and those who had a prior pregnancy with a chromosome abnormality or where the man has abnormal sperm analysis. Any one or a combination of these factors could increase the risk of abnormality in embryos.”
While it is true that embryo quality is a major factor for implantation, couples that do not conceive even after Pre-implantation Genetic Testing (PGT), could be facing endometrial conditions. This is called poor endometrial receptivity. Since visual examination by sonography
alone cannot reveal a problem like this, doctors at IVI Fertility turn to more advanced technology called Endometrial Receptivity Array (ERA). This test helps in identifying the receptive status of the endometrium. They then perform embryo transfer at the most appropriate time (Personalized Window of Implantation) to improve the chances of pregnancy.
Previously, doctors had no choice but to repeat In-vitro Fertilization (IVF) cycles till there was success. Now, with the ERA test, individualized embryo transfer is possible, which increases the success rate of pregnancy and reduces the time that patients have to wait to achieve a pregnancy. ERA results are consistent in different cycles of the same patient when hormonal treatment is maintained. The cost of the test is relatively inexpensive when considering the overall costs of fertility treatment and potential benefits of evaluating endometrial receptivity.