Approximately 15% of couples attempting their first pregnancy meet with failure. Reproductive centres define these patients as primarily infertile if they have been unable to achieve a pregnancy after one year of unprotected intercourse. Conception normally is achieved within twelve months in 80-85% of couples who use no contraceptive measures, and persons presenting after this time should therefore be regarded as possibly infertile and should be evaluated. Data available over the past twenty years reveal that in approximately 30% of cases pathology is found in the man alone, and in another 20% both the man and woman are abnormal. Therefore, the male factor is at least partly responsible in about 50% of infertile couples.
Male infertility affects approximately 2-7% of couples around the world. Over one in ten men who seek help at infertility clinics are diagnosed as severely oligozoospermic and azoospermic.
Microdeletions of the Y chromosome are a recently discovered cause of spermatogenetic failure resulting in male infertility. After the Klinefelter syndrome, Y-chromosomal microdeletions are the second most frequent genetic cause of male infertility.