Rates of live birth in women who undergo treatment with assisted reproductive technology (ART) are commonly reported on a per-cycle basis. However, assessing success rates for ART on a per-cycle basis has limited value for women receiving continued treatment; cumulative success rates are more relevant. Two previous studies of cumulative live-birth rates with ART evaluated linked cycles for a selected population of women in Massachusetts.
The present study expanded these 2 analyses and estimated cumulative live-birth rates by linking national data from cycles of ART in the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database to individual women treated between 2004 and 2008. Cumulative live-birth rates were evaluated as a function of the method of treatment, including the use of autologous versus donor oocytes. Conservative estimates of the cumulative live-birth rate were calculated with the assumption that women not returning for treatment would never have a live birth; optimal estimates assumed that the live-birth rate among women not returning for treatment and those who continued treatment would be the same.
The data set used for analysis included 246,740 women, with 471,208 cycles and 140,859 live births. Analysis of cycles with autologous oocytes showed a progressive decline for both optimal and conservative estimates of the cumulative live-birth rate with increasing maternal age and cycle number (P < 0.001 for both). With use of autologous oocytes, the conservative and optimal estimates of live-birth rates declined by the third cycle with increasing maternal age (from 63.3% and 74.6%, respectively, for women aged ≤31 years to 18.6% and 27.8% for those 41 or 42 years of age and to 6.6% and 11.3% for those aged ≥43 years). When donor oocytes were used, rates were higher (60% and 80%, respectively) for women of all ages. Transfer of the embryo at the blastocyst stage (day 5 or 6) was associated with higher live-birth rates than transfer at the cleavage stage (day 2 or 3). When fresh autologous oocytes were used, conservative and optimal estimates of cumulative live-birth rates at the third cycle were, respectively, 42.7% and 65.3% for transfer of cleavage embryos versus 52.4% and 80.7% for transfer of blastocyst embryos.
These findings show that live-birth rates approaching natural fecundity can be achieved with ART when patient and embryo characteristics are favorable. Moreover, the data indicate that when autologous oocytes are used, live-birth rates are lower in older women than in younger women. In contrast, when donor oocytes are used, rates are similar among women of all ages.