Male Infertility
The World Health Organization (WHO) has defined infertility as the inability of a sexually active couple to achieve pregnancy despite unprotected intercourse during the fertile phase of the menstrual cycle for a period of greater than 12 months. The percentage of couples seeking medical treatment for infertility is estimated at 4% to 17%.
The estimates of prevalence rates of infertility and subfertility depend crucially upon the method used to define these conditions. The WHO definition was based on studies that used time to pregnancy estimations and found the probability of conception to be 20% per cycle or ∼85% to 90% per year. Even among couples who do not conceive within 12 months, 55% have a live birth within the next 36 months. When the duration of infertility exceeds 4 years, the conception rate per month drops to 1.5%.
In 20% of infertile couples, the primary problem resides in the male partner; in an additional 26%, problems reside in both the male and the female partner; thus, the male partner contributes to infertility in about half the couples. The occurrence of infertility substantially affects a couple’s relationship, quality of life, and health care expenditures.
COMMON DIAGNOSES IN MEN BEING EVALUATED FOR INFERTILITY
Diagnostic Category | Incidence (%) |
---|---|
Idiopathic infertility | 50-60 |
Primary testicular failure (chromosomal disorders including Klinefelter’s syndrome, Y chromosome microdeletions, undescended testis, irradiation, orchitis, drugs) | 10-20 |
Genital tract obstruction (congenital absence of vas, vasectomy, epididymal obstruction) | 5 |
Coital disorders | <1 |
Hypogonadotropic hypogonadism (pituitary adenomas, panhypopituitarism, idiopathic hypogonadotropic hypogonadism, hyperprolactinemia) | 3-4 |
Varicocele[*] | 15-35 |
Other (sperm autoimmunity, drugs, toxins, systemic illness) | 5 |
* | Although varicoceles are observed with higher frequency in infertile and subfertile men than in fertile men, their role and contribution to infertility remains unclear. |