The only way to decrease the incidence of multiple pregnancies in the IVF/intracytoplasmic sperm injection (ICSI) population is to introduce single-embryo transfer (SET). This study investigated the impact of the progressive introduction of SET for the whole IVF/ICSI population from the patients' point of view by calculating the cumulative live-birth delivery rate. During a 5-year period (2001-2005), the outcome of 2164 cycles with oocyte aspiration in 1047 patients was analysed. A subanalysis was made to calculate the additional effect of frozen-thawed cycles. Survival analysis was performed with the Kaplan-Meier method and the endpoint was live-birth delivery. In this 5-year period, the cumulative live-birth delivery rate per patient was 51% after three IVF/ICSI cycles and 58% after six cycles. With a more permissive method of survival analysis, these results were 64% and 85%, respectively. The additional effect of the frozen-thawed cycles since reimbursement was only 5%. SET was progressively introduced in this period leading to a twin live-birth delivery rate of only 6.7%. It is concluded that a favourable outcome was observed for the cumulative live-birth delivery rate since the introduction of SET but with a disappointing additional effect of the frozen-thawed cycles.