The average success rate of IVF globally is under 50 percent. This means that almost half the people have unsuccessful IVF cycles and unfortunately, there is no scientific way to determine the exact reason for failure of IVF.
IVF is an expensive procedure with no guarantee of success. Once you get your head around the cost of IVF, the most important concern for patients is to know about their chances of success.
The IVF clinic you choose, lab factors, the method of performing the procedure, the competence of the embryologist are all factors that can affect your IVF results but over 50 percent of IVF cases will fail even if these conditions are perfect.
If even after choosing the right IVF clinic, you are wondering why did my IVF fail, read the below to get an idea of personal factors that could be causing problem.
Like most biological processes, pregnancy and the development of an embryo inside the human womb is a complex procedure. What we do not know about pregnancy is much greater than what we do know.
However, when looking at the reasons for failure of IVF, infertility specialists have been able to identify some specific factors that may be to blame:
1. Embryo implantation failure
The IVF process is complicated and there is no way to figure out the stage at which the success is being blocked. But one of the most common causes of IVF failure is the failure of embryo to attach to the uterus lining.
Embryo implantation failure could happen either due to problem with the embryos or problem with the uterus, but it cannot be determined for sure which of these has caused the failure in your specific case.
Most infertility specialists believe that arrest of embryos is responsible for implantation failure in over 90 percent of the cases.
Several of the embryos created will die by day 5, but even the good ones that survive the initial days and actually look healthy, also die in some time after being transferred to the uterus.
Now there are a number of causes that can result in poor quality, weak embryos, which do not grow beyond a certain stage, but unfortunately these issues are still considered a “black box” in the IVF world and there is no fail-safe way to ascertain what is wrong with the embryos.
Genetic or chromosomal abnormalities can sometimes make the embryo too weak for IVF, while other times the embryo just does not have enough cells to survive and is unlikely to grow.
One way to improve your chances of IVF success is to opt for PGS testing with IVF to study the genetic content of embryos before transferring them to the uterus. This allows the doctor to select the embryos with most chances of success.
Most of our network IVF doctors in India, Thailand, and Malaysia report success rates between 60%-75% in IVF with PGS.
2. Quality of eggs
Embryo implantation rates are higher (at around 50%) in women near the age of 35, as compared to just around 12% in women over 40 years of age.
Often, older women will ask:
- What is wrong with my uterus?
- Why is it not accepting embryos?
At this stage, some are even tempted to hire a surrogate but science does not agree.
In most cases, where the uterus is free of any obvious problems, switching to IVF with donor eggs is more likely to bring you success. If your eggs are responsible for the problem, even transferring them to a surrogate’s uterus will produce the same result.
In 2016, a 70-year old Indian woman gave birth to a baby she had through IVF. The point here is—the uterus in older women CAN carry a pregnancy to term, given there are no other medical issues.
IVF failure in older women is mostly caused due to older eggs which are not viable for pregnancy.
3. Female age & Ovarian response
Age of the woman, the health of uterus, and the ways her body responds to IVF medications also play a great role in IVF success.
Normally, a woman’s ovary will release one egg a month—from a collection that is fixed at birth and declines sharply after the mid 30s.
Before an IVF cycle, medications are administered to get the ovaries to produce more eggs. If you already have a reduced number of eggs or have elevated FSH levels, your body might not respond properly to IVF medications, which is not a good sign.
If your body responds well to the medication and produces more eggs, you have good chances of IVF success as it indicates the normal functioning of hormones in your body. But if it doesn’t, then your chances of IVF success are reduced.
These simple fertility tests for women will give you an idea about your fertility levels and help the doctor decide on the most viable course of treatment for you.
4. Sperm quality
The sperm perform a complex role in fertilization of the female egg and in order to do so, they must be healthy, motile, and sufficient in quantity.
The sperm and eggs both have specific receptors on their surface that allow for their interaction and when that happens, enzymes are released from the sperm head that cause a hole in the outer membranes of the egg, allowing it to penetrate through.
However, barring chromosomal factors, sperm are usually not the among the reasons for failure of IVF because any quantitative or qualitative problems with the sperm are easily detected during semen analysis and the patients are then given the option of intracytoplasmic sperm injection (ICSI) or IVF with donor sperm.
5. Genetic & Chromosomal causes
The rate of chromosomal abnormalities in human embryos is one of the major factors for IVF failure.
Various studies have shown that the rate of chromosomal abnormalities in human eggs (and therefore in human embryos) start to increase significantly after the mid-30s.
IVF with self-eggs in women over 40 years of age is known to result in poor quality embryos, almost 75% of which are chromosomally abnormal. Hence, the low rate of IVF success in older women.
It is believed that older eggs have an inefficient spindle apparatus that is unable to line up the chromosome pairs properly. Pairs of chromosomes are not split properly, leading to an alteration in the required balance of 23 chromosomes per egg.
Chromosomal anomalies in the sperm can also lead to chromosomally abnormal embryos but that incidence is reported to be small at 1% to 2% of cases as compared to about 20% to 90% of human eggs.
The chromosomal competence of an embryo can be detected with preimplantation genetic screening (PGS) testing.
It is hard to determine the exact reason for failure of IVF, but even an idea of the possible cause of failure—age, quality of eggs/sperm, health of uterus, etc.—could help in planning the treatment in a way that tackles the very problem and allows for better chances of success.
I’ve sometimes noticed that patients keep insisting on using their own eggs, or going for the treatment in a certain manner even after several failed attempts at IVF. Honestly, sometimes it works.
But if your IVF has not resulted in success after many attempts, it might be an indication for change of strategy.
If the eggs produced are not enough, a change in medication protocol might help. If you have PCOD or thyroid problems, you might be asked to see an endocrinologist to bring your hormones to a normal level so as to prepare the body for a healthy pregnancy.
Failure of IVF is hard on every person, but it happens either because the embryos you are producing are not healthy or your body is not ready to carry a pregnancy.
Do NOT despair. Choose a competent, experienced infertility specialist who can take you closer to looking for the reasons for failure of IVF in your case and provide you with solutions that can take you closer to having your baby.