BACKGROUND: The outcome of in vitro fertilization (IVF) has been widely investigated over the last 30 years, but evaluation was mostly based on pregnancy rate per oocyte retrieval. Our objective was to estimate the cumulative live birth rate after four IVF aspirations, using multiple imputation that takes into account treatment interruptions. METHODS: We analysed data from 3037 couples beginning IVF treatment between 1998 and 2002 in two French IVF units. Multiple imputations were used at each aspiration to impute the IVF outcome (delivery or not) for couples who interrupted treatment. The global success rate after four aspirations was then computed. RESULTS: At the first aspiration, 21% of couples obtained a live birth and 24% discontinued treatment. The multiple imputation method provided an estimated cumulative live birth rate at each aspiration as if no couple discontinued treatment: 35% at the second aspiration and 41% at the third. The cumulative success rate after four aspirations was estimated at 46% (95% CI: 44-48%). CONCLUSIONS: Multiple imputation is a promising method for estimating the cumulative success rate of IVF. It could provide new insight on IVF evaluation and should be tested in further studies.