Most IVF cycles result in the formation of good looking embryos ; and most patients naturally expect these embryos to become babies once they are transferred into their uterus. After all, the doctor has finished doing all the hard work in the lab. Once the embryos are put back in the uterus, than all we have to do is to allow nature to take its own course - and if the embryos look so good, then how can my IVF cycle fail ? However, the sad truth is that most embryos do not implant, which is why the success rate of IVF is still not 100% !

The question every patient asks after a failed IVF cycle is - Why didn't the embryos implant ? And what should we change the next time, to improve our chances of success ?

When the embryos are good looking , the natural tendency is to blame the uterus. Many patients naively believe that their uterus is " rejecting the embryos" or their their "uterine environment" is not favourable ( too hot or too cold or too acidic ). Others blame the fact that they did not rest, as a result of which their embryos could not stick to the uterus; or that the fact that they were so stressed did not allow nature to do its magic.

Since most infertile patients have low self-esteem and believe that their bodies are defective ( which is why they are not getting pregnant in their own bedroom in the first place) , they are very willing to believe that it's their uterus which is defective.

Sadly, after a failed IVF cycle, many doctors also proffer this as an explanation for the failure. This is because most doctors are usually very optimistic at the time of embryo transfer. They proudly display the beautiful embryos they have made to the patient ; help her to admire her beautiful embies; pat themselves on doing such a good job in the lab; and pump the patient with lots of hope. They have helped the patient to cross a major fertility hurdle, thanks to their skill, expertise and technology , and they take pride in this !

Now, when the cycle fails, it follows that if the clinic is so good at making good embryos , then the problem has to lie elsewhere - and the only other possibility left is the uterus ! Unfortunately, I feel this has become a highly sophisticated form of victim blaming, where the patient is being blamed for the failure of the IVF cycle. Rather than being honest with the patient and telling her that we simply just do not know why some embryos fail to implant, many doctors will propose a battery of tests ( which are sophisticated and expensive, but of no value at all !) to evaluate the uterus and the uterine environment. These will include tests such as uterine immune function tests for NK ( natural killer) cells ; and endometrial function tests for integrins in the USA; to tests for checking for TB using PCR in India. Lots of these test results will come back as abnormal - after all, the more the tests you do, the higher the chances of finding a test which falls outside the normal range ! The doctor can then point to this abnormal result and pin the blame for the failure on the abnormal uterine environment, with scientific hubris . Many doctors also use this as a convenient pretext to suggest surrogacy , because it is much more profitable !

The truth is that surrogacy is an expensive and complex treatment option, which is best reserved for women without a uterus; or those whose uterus is irreparably damaged. Research shows that the reason for failed implantation is much more likely to be genetically abnormal embryos ( because of poor quality eggs), rather than a uterine problem.

Just because the embryo looks perfect does not mean it is genetically normal ! Remember that human reproduction is an inefficient enterprise, even in the bedroom - it takes time to make a baby in viv0 . The reason every fertile couple does not get pregnant every month they have sex is because even though the sperm do fertilise the egg, the resultant embryos do not implant, because of an intrinsic genetic abnormality. This failure to allow implantation is actually nature's defense mechanism against allowing the birth of abnormal babies.

While these genetic defects in embryos are often random, they are commoner in older women. This is because the eggs of older women have more genetically abnormalities, because they have "aged" and have genetic defects, which cannot be screened for.

So what' s the reason for failed implantation - is it the uterus or the egg ? The answer is simple - the vast majority of the time it's the egg. This is why success rates in older women who use donor eggs are so high ! There's nothing wrong with their uterus, and younger ( genetically normal) embryos can happily implant in their uterus.

Unfortunately, the uterus continues to be blamed unfairly by both patients and doctors. Now that Aamir Khan decided to do surrogacy because his wife had a miscarriage, the number of patients who will want to use another woman's uterus when they fail IVF or have a miscarriage is going to go through the roof !