Cumulative probability of achieving an ongoing pregnancy after in-vitro fertilization and intracytoplasmic sperm injection according to a woman's age, subfertility diagnosis and primary or secondary subfertility.

The aim of this study was to estimate reliable cumulative probabilities of achieving an ongoing pregnancy after successive in-vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycles, according to a woman's age, subfertility diagnosis and primary or secondary subfertility. Therefore reasons for quitting treatment without achieving an ongoing pregnancy were taken into account. Moreover, we studied whether there were trends in cumulative probabilities after adjustment for potential confounding effects of the other two characteristics, duration of subfertility, year of first treatment and reason for quitting treatment. In total, 2984 IVF/ICSI cycles were performed in 1315 couples at the University Hospital Nijmegen, The Netherlands, between 1991 and 1998. The 'realistic' cumulative probability of achieving an ongoing pregnancy was 54.5% after five consecutive IVF/ICSI cycles, which was about 10% lower (absolute value) than the optimistic probability calculated by life-table analysis and about 10% higher (absolute value) than the most pessimistic estimate. Women of 35 years or younger had a higher probability of achieving an ongoing pregnancy than the older women. As ICSI is now an option, there were no obvious differences between the subfertility diagnosis subgroups. The cumulative probability after the first two IVF/ICSI cycles was higher in women with secondary subfertility than in those with primary subfertility; this advantage disappeared after further treatment. These trends remained valid after adjustment for confounding factors.