The first question that arises in a patient’s mind after an IVF failure is ‘Why did my cycle fail? It is painful because your dreams are shattered, your hard-earned money has gone down the tube and you do not know what to do next!
Sometimes it is difficult to understand the reason why IVF cycle couldn’t succeed, when we obtain eggs and sperm, combine them in a successful laboratory to develop embryos and put what appear to be healthy dividing embryos into the uterus. They have done everything possible, improved their diets, reduced their stress levels, and taken their medication religiously. After two weeks wait finally, the test date arrives and it’s not a positive result. The first question that arises in a patient’s mind after an IVF failure is ‘Why did my cycle fail? It is painful because your dreams are shattered, your hard-earned money has gone down the tube and you do not know what to do next!
Nevertheless, there are some specific factors that we have identified that can occasionally lead to IVF failure.
Egg Abnormalities: The most important factor for IVF failure is the Egg. The eggs are responsible for successful fertilization and embryo development. Once sperm and egg fused together they lead to the formation of embryo. The single cell embryo subsequently divides into daughter cells through a process regulated by the organelles that reside within the cytoplasm of the egg.
As the cells divide, half of the chromosomes migrate in one direction and the other half migrate in the exact opposite direction, resulting in two identical cells. With time, these migrating tracts can become defective resulting in abnormal separation of the chromosomes. The result is an embryo with an abnormal number of chromosomes that, depending on the severity of the error, may stop growing at an early stage in the lab or eventually ends as a biochemical pregnancy or first trimester miscarriage.
Age has a great impact on the egg. After age 30 egg quantities and quality begin to decline and the rate accelerates after age 35, so that by age 40 only about 10% of a woman’s eggs are normal. The decrease in egg number, when combined with poor egg quality, often translates into a lower chance of creating a normal embryo with IVF.
Sperm Abnormalities : It is less common factor affecting the success of IVF cycle. In order for sperm to migrate to the egg, they must be motile; in other words, the tail of the sperm must be able to propel the sperm through the female reproductive tract to the egg.
The genetic material packed within the sperm head may be abnormal even when a routine semen analysis shows normal sperm concentration, motility, and morphology. Damage to sperm DNA can be caused by exposure to chemicals, free radicals and oxidants (byproducts of metabolism), and tobacco use. Fertilizing an egg with an abnormal sperm can result in an abnormal embryo.
Embryo Selection Method: It depends on three factors
Day three, embryos that have developed to at least the 6 cell stage have a much better prognosis for success than embryos that have 5 or fewer cells. An embryo that gradually reaches the 8 cell stage by day three is much more likely to do well than an embryo that has delayed fertilization and rapid growth towards the end of this time period. Embryos that are of a better grade (grade 1, 2 or even 2.5) are much more likely to implant that those embryos with lower grades (3 or 4).
Embryo Transfer: During embryo transfer procedure one of the most important steps of the entire cycle – embryos must be placed in the correct location. Embryo transfer is difficult task, because of cervical stenosis or acute angulations of cervix. Prior to the stimulation cycle, a trial transfer is routinely performed to map the uterus and determine the optimal placement site for the embryo. Placement of a cervical traction stitch after egg retrieval can help counteract a sharply tilted uterus. Ultrasound guidance can also be helpful in guiding the transfer catheter to the appropriate site.
There are lots of other reasons for failure of the IVF cycle, but these are the most common.
