The primary intention for the choice of fertilization modality between IVF and ICSI is the prevention of a relative or total fertilization failure. Such treatment failure is best prevented through ICSI, which results in slightly higher clinical pregnancy rates per started cycle. After embryo transfer, there are no differences in the success rates of IVF and ICSI. The supposed cumulative live-birth rates are useful as a basis for counselling subfertile couples to help reduce the high discontinuation rate, which is still the main reason for inefficacy in ART. Following an unsuccessful first treatment cycle, the prognosis remains positive, but until success is achieved, more treatment cycles are necessary.