Female age has been shown in multiple studies to be a predictor of poor reproductive success with assisted reproductive technology (ART) resulting in decreased fertility rates, increased miscarriage rates, and decreased embryo implantation rates. This decline in female reproductive function can be explained partly by an increase in chromosomal anomalies observed in oocytes and embryos.
Compared to the effect of the aging oocyte, the effect of male age on reproductive success has been studied in much less detail. Controversy exists whether male age has an effect on the reproductive potential of a couple. Paternal age has been shown to increase the risk of infertility and adverse pregnancy outcome in patients not undergoing ART. However, a recent study that analyzed success rates in 558 IVF cycles with donated oocytes found no paternal age effect on fertilization or live birth rate.
Compared to the female, the age of the male partner seems to have little effect on reproductive potential. Alterations in the hypothalamic-pituitary axis and decreased testicular function have been reported to decrease serum steroid levels in aging men. Some reports have suggested a decline in motility and morphologic semen characteristics, while other reports have noted little change in semen characteristics. Recently a review of studies evaluating the effects of male age on fertility and semen quality concluded that increasing age of the male partner is associated with lower semen volume, motility and morphology; however, no change in sperm concentration was noted. This review found that male fertility declines somewhat with age, particularly in men older than 50 years. Although there was a trend for lower pregnancy rates associated with increasing male age, the data in most studies are difficult to interpret because few studies attempted to adjust for the female age.