Why ivf can be unsuccessul? if it possible to understand the reasons for future treatment?

Many reasons: Mother nature is inefficient. Not al embryos will make a baby. Ivf pregnancy rates, even at the best programs, are nowhere near 100%. On the other hand, ivf is an extremely effective infertility treatment. Many patients that fail a cycle of ivf will eventually conceive, but it may take more than one try. Talk with your doctor about ways to improve your chances of success next time. Best of luck.

Many reasons: Ivf can be unsuccessful for many reasons. There could be egg or sperm quality issues, embryo may be genetically abnormal or the uterine lining may not be receptive to implantation. These are the main ones and many unknowns are also there. Some of these can be suspected based on findings from the failed cycle. Talk to your doctor so you can have a better outcome in your future attempt. Good luck.

IVF: Generally, it will need more than one attempt with ivf to have a successful pregnancy. Please have faith as well as patience. Good luck !