Researchers from the University of California suggest that the chance of successful in-vitro fertilization treatment reduces drastically

For those couples who used intrauterine insemination (IUI), the chances of a successful treatment came in the first, second or the third cycle while the chances of pregnancy reduced after undergoing four or more cycles.
“Cycle-based fertility treatments may offer a point of diminishing returns for infertile couples”, the researchers wrote in their study which was published in the journal Fertility and Sterility.
Source-Medindia