Today, reproductive technologies such as IVF are primarily studied in women of childbearing age, but in men, there is also an age-related decline in sperm function and male infertility. Although male “menopause” is not as precisely defined as female menopause, there is a decline in testicular function, including a decrease in annual testosterone levels.59 Semen parameters include semen volume, viability, and morphologic decline with age, although there is no proven decline in sperm density.60 Studies of the effect of age on natural fertility in men often fail to explain the effects of age on fertility. Studies of the effect of male age on natural fertility often fail to account for the effect of female age. One study showed a 3% annual decline in the odds of pregnancy, while others concluded that a man’s age alone had little effect on the monthly pregnancy rate in natural cycles.61 In a similar vein, studies of ART treatment often fail to adequately control for the age of the woman. The results of one study suggest that male age greater than 35 years may have an effect on IUI, however, most studies suggest that although male age causes low sperm motility and low pregnancy rates, it does not affect pregnancy rates with IVF/cellular sperm injection (ICSI). No difference was found in donor egg cycles. In couples undergoing ART, it appears that the age of the male has little effect on the cell count of the cleavage globe embryo. However, a significant reduction in the rate of day five blastocyst formation and the number of freezable embryos has been reported. Male age over 40 years does seem to increase the risk of spontaneous abortion, even after controlling for female age. As far as chromosomal abnormalities are concerned, the mother’s age is a very significant influencing factor, in contrast to the father’s age, which has a very small effect, and has even been found to have no effect in many studies, once the mother’s age has been controlled for. However, recent studies have shown that the father’s age, by itself or in combination with the mother’s age, increases the risk of Down syndrome. Although there is no consistent finding of an association between preterm birth and low birth weight, a study conducted in the United States and another population-based study in Alberta did not find such an association, even after multivariate logistic regression analysis. Advanced paternal age has been associated with autosomal dominant disorders such as Alport syndrome, congenital chondrodysplasia and multiple neurofibromas. The risk of autosomal dominant disorders in newborns with fathers older than 40 years has been estimated to be <0.5%. However, the American College of Medical Genetics does not recommend additional prenatal testing solely because of the advanced age of the father (≥40 years), but only recommends prenatal counseling for the potential risks of advanced paternal age if necessary. Male infertility has elevated rapidly in recent years, accounting for one-third of the infertility population and another nearly one-third of problems in both couples. The diagnosis of Y chromosome microdeletions not only clarifies the etiology of azoospermia or oligozoospermia, but also accurately characterizes the prognosis. Clinically relevant Y chromosome microdeletions are usually seen in patients with azoospermia or sperm concentration of less than 1 × 106/ml, and in a few cases, the deletion is also seen in infertile patients with sperm concentration between 1 × 106/ml and 5 × 106/ml. General clinical parameters such as hormone levels, testicular volume, varicocele, testicular malformations, and infections do not have any predictive value for the presence of Y chromosome microdeletions.