For most couples having difficulty achieving a pregnancy their chance of achieving a pregnancy is not zero, it is just lower than the average rate of conception—unless both Fallopian tubes are completely blocked, there is no sperm, or the woman never ovulates. Ovulation induction (or superovulation) with IUI helps patients to achieve pregnancy rates closer to the natural per cycle chance of pregnancy for women in their age group who do not have infertility (see fig 1).
Repeated failed rounds of IVF can help identify causes of infertility. For example, if sperm and egg quality are normal, then the conception issue may be rooted at the embryonic or implantation level. In other words, if IVF fails to result in pregnancy despite successful fertilization, embryonic development or implantation may be to blame. Still this is a very expensive way to start getting answers.