Why IVF fails?
She was angry, frustrated and depressed. She had just failed her attempt at IVF.
“Doc, I have been spending so much time and money trying to conceive. I always think that IVF should work for me as both my partner and I are healthy. In my IVF cycle, my doctor has retrieved 6 “good” eggs from my right ovary and had two of them fertilized after injecting my husband’s sperm into the eggs. The embryos were then transferred to my womb without a hitch," she recounted with tears in her eyes. “Can you tell me what went wrong?”
D, a 36-year-old lady had been married for 4 years and had problems conceiving. Her reproductive system was normal but her husband’s semen analysis was slightly below par. IVF was her last resort as other methods of helping her conceive had failed. Though she had been counselled regarding the chances of success with IVF, she still felt grief and loss.
There are many reasons why IVF fails. The common reasons are as follows:
1.The aging egg:
As the woman ages, the quality of the egg deteriorates. This will affect the chances of pregnancy with IVF. The younger the patient, the higher the chances of success with IVF. For women aged 25, the success rate of IVF is around 30-35 %, but for those aged 40 and above, it is around 5%. Even if the egg retrieved appears normal under the microscope, the genetic material present may not be good.
2. The imperfect sperm:
The DNA within the sperm may be defective even though the semen analysis is normal. Injecting a single sperm into the egg (ICSI) can increase the chance of fertilization but does not ensure that a normal sperm has been chosen. Fertilizing an egg with an abnormal sperm can result in an abnormal embryo.
3.The defective embryo:
Embryo quality is an important contributing factor to IVF failure. Many defective embryos are unable to implant after transfer to the uterus. Embryos that look healthy in a lab may have genetic or chromosomal defects that prevent them from developing. These abnormal embryos are often the reason behind miscarriages and implantation failure during IVF. Some research studies have suggested that defective embryos can account for 50 % of IVF failure.
4. Poor Implantation site:
If the uterine lining is injured during a difficult embryo transfer or if the womb is congenitally malformed with a partition(septum), the embryo may not get implanted. Other implantation issues include the presence of polyps, multiple fibroids, thin lining of the womb and intrauterine adhesions from previous womb surgery.
In addition to the above reasons, there are many other factors that can impact one’s chances for a successful pregnancy with IVF. These include the response of the ovary to stimulation, lifestyle factors of the patient such as body weight and smoking, laboratory techniques and the skill of the specialists performing the egg retrieval and embryo transfer.
After D listened to my explanation with regards to the intricacies and complexities of the IVF process, she finally came to terms with her grief.
“Thanks doc. I will take some time to think through and decide what I will do next,” she said.