The impact of the woman's age on the success of standard and donor in vitro fertilization

Objective: To study the effect of the age of the woman who provides the oocytes or who receives the embryos on results of IVF-ET. Design: Historical cohort study. Multivariate regression analysis was used to study the age effect continuously and after adjustment for confounding. Setting: Patients of the University of Southern California, Los Angeles, California. Patient(s): Couples who underwent standard (n = 277) or donor IVF-ET (n = 294) between January 1991 and July 1995. Intervention(s): One cycle of standard or donor IVF-ET. Main Outcome Measure(s): Successive IVF outcomes from number of oocytes to ongoing pregnancy and several measures of pregnancy loss. Result(s): The number of oocytes decreased with aging of the oocyte provider. More women who received oocytes from donors aged 20 to 23 years had at least one good embryo transferred than women who received oocytes from older donors. The age of the woman who received the embryos had no effect on IVF outcomes. In women > 40 years who underwent standard IVF, the probability of pregnancy decreased. No such relationships were observed for donor IVF, but all the oocyte donors were younger. Conclusion(s): An age effect for ongoing pregnancy was only found in women > 40 years who underwent standard IVF independent of the lower number of oocytes and suggests decreasing oocyte quality.