In vitro fertilization or IVF is not always successful the first time it is attempted. In the IVF process eggs are retrieved from a woman's ovaries after taking ovarian stimulation medications anywhere from 10-12 days typically. Once the eggs are retrieved, they are fertilized with the sperm sample. The embryos are created and the best of those embryos are transferred back into the uterine cavity. Remaining embryos that are of high quality can be frozen or cry preserved for later use. A question that typically arises is "What happens if the first cycle doesn't work?" Well, it depends on what happened in the first cycle. If the cycle resulted in a good number of eggs and high quality embryos, but implantation did not occur, then, the physician needs to consider any other possibilities.
For example, is the uterine cavity normal? Is there evidence of autoimmune response that could be effecting implantation? Or are the embryos genetically not normal when they appear morphologically under a microscope to be normal? These are all factors that the reproductive endocrinologist is considering. However, rest assured that after the first cycle of IVF, even if unsuccessful, the next cycle generally results in the same success rate. It does not diminish, necessarily, just because it's the second cycle or the third cycle. There is data, however, that suggest with numerous failed cycles, the chances of conception do become lower and lower.
It's probably not reasonable for many women, depending on their clinical situation, to do multiple cycles of in vitro fertilization as the chances of success do diminish and the potential risk of the medication increase. Many babies born by in vitro fertilization, most babies born by in vitro fertilization, in the world to date, would never have occurred if the couple stopped at the first cycle of IVF.