The Male Infertility Best Practice Policy Committee of the American Urological Association, Inc. (AUA) and the Practice Committee of the American Society for Reproductive Medicine (ASRM) collaborated to produce recommendations intended to assist family physicians, urologists, gynecologists, reproductive endocrinologists, and reproductive researchers in the diagnosis and treatment of male infertility. The recommendations were submitted for peer review and were approved by the Boards of Directors of the AUA and the ASRM. This review, which was published in The Journal of Urology, May 2002, offers recommendations for the optimal diagnostic evaluation of the male partner of an infertile couple.
Male infertility factors are present in about 20 percent of infertile couples and contributory in about 30 to 40 percent. Male infertility factors are almost always defined by an abnormal semen analysis. When a semen analysis is normal, other male factors may play a role. Patients with normal semen analyses rarely have sperm that do not function in a manner necessary for fertility.
Male infertility can result from a variety of conditions. Of those conditions that are identifiable, some are reversible and some are not. The purpose of the evaluation of the male is to identify conditions contributing to infertility that are (1) potentially reversible; (2) irreversible, but suited to assisted reproductive techniques using the man's sperm; (3) irreversible and not suited to assisted reproductive techniques; and (4) potentially life-or health-threatening and that may underlie the infertility. Also, detecting genetic causes of male infertility can allow couples to become informed about the possibility for transmitting genetic abnormalities to their offspring and to obtain genetic counseling.
When to Perform an Infertility Evaluation
An infertility evaluation should be performed if a couple has not achieved conception after one year of unprotected intercourse. An evaluation should be performed earlier if male infertility risk factors exist (e.g., a history of bilateral cryptorchidism); if female infertility risk factors exist, including age over 35 years; and if the couple questions the man's fertility potential. Additionally, men who are concerned about their fertility status and who do not have a current partner should undergo an evaluation.
Elements of an Infertility Evaluation
The initial screening of the male should include a reproductive history and two semen analyses. The reproductive history should include (1) the frequency and timing of intercourse; (2) prior fertility and the duration of current infertility; (3) childhood illnesses and developmental history; (4) systemic illnesses and previous surgeries; (5) sexual history, including sexually transmitted diseases; and (6) gonadal toxin exposure, including heat. Additionally, the screening should include a history of prescription and non-prescription drug use and a family reproductive history.
During the general physical examination, particular attention should be given to the genitalia. The evaluation should include (1) examination of the penis, including the location of the urethral meatus; (2) measurement and palpation of the testes; (3) checking for the presence and consistency of the vasa and epididymides; (4) checking for the presence of a varicocele; (5) body habitus and secondary sex characteristics, including hair distribution and breast development; and (6) a digital rectal examination. A definitive diagnosis of congenital bilateral absence of the vasa deferentia can be made by physical examination.
The semen analyses, which help define the severity of the male factor, should be performed at least one month apart. Patients should be provided with standard instructions for semen collection, including abstaining from sexual activity for two to three days before collection. The semen can be collected by masturbation or intercourse using semen collection condoms. If the collection takes place at home, the specimen should be kept at room or body temperature during transport and examined within one hour of collection.
The semen analyses provide information on semen volume and sperm concentration, motility, and morphology. While reference ranges for the seven parameters of semen analysis have not been established, values based on clinical literature are available. They include ejaculate volume between 1.5 and 5.0 mL; pH greater than 7.2; sperm concentration greater than 20 million per mL; total sperm number greater than 40 million per ejaculate; motility greater than 50 percent; forward progression more than 2 (on a scale of 0 to 4); and normal morphology, which varies between the World Health Organization and Kruger (Tygerberg).
Additional procedures and testing may be used to elucidate problems discovered during the full evaluation. An endocrine evaluation should be performed if (1) the results of the semen analyses are abnormal, especially if sperm concentration is less than 10 million per mL; (2) sexual function is impaired; and (3) other clinical findings suggest a specific endocrinopathy. The minimal initial endocrine evaluation should include serum testosterone and serum follicle-stimulating hormone levels.
A post-ejaculatory urinalysis should be performed if ejaculate volume is less than 1 mL, except in patients with bilateral vasal agenesis or possible hypogonadism. Low-volume or absent ejaculate indicates retrograde ejaculation, lack of emission, ejaculatory duct obstruction, hypogonadism, and congenital bilateral absence of the vasa deferentia.
To determine if ejaculatory duct obstruction exists, transrectal ultrasonography (TRUS) is indicated in patients who are azoospermic with palpable vasa and low ejaculate volumes. Some experts recommend performing TRUS in oligospermic patients with low ejaculate volume, palpable vasa, and normal testicular size.
Scrotal ultrasonography is indicated when physical examination of the scrotum is difficult or inadequate, or when a testicular mass is suspected.
Specialized Clinical Tests
Specialized testing of semen is not required for diagnosis of male infertility. However, some tests may be useful for a few patients to identify a male factor contributing to unexplained infertility, or to select therapy (e.g., assisted reproductive technology).
About two thirds of men with clinical cystic fibrosis have mutations of the cystic fibrosis transmembrane conductance regulator gene. Therefore, genetic testing for gene mutations in the female partner should be offered before proceeding with treatments that use the sperm of men with congenital bilateral absence of the vasa deferentia. Men with nonobstructive azoospermia and severe ogliospermia (fewer than 5 to 10 million sperm per mL) should be informed of the potential genetic abnormalities associated with azoospermia or severe oligospermia. Before performing intracytoplasmic sperm injection, karyotyping and Y-chromosome analysis should be offered to men who have nonobstructive azoospermia and severe oligospermia. Genetic counseling may be offered when a genetic abnormality is suspected in the male or female partner, and it should be provided when a genetic abnormality is detected.