Diagnosis of Male Infertility
The search for the cause of infertility usually begins with the male, because male examination and testing is less complicated. A thorough examination and a review of the man's medical and surgical history are necessary, because chronic disease, pelvic injury, childhood illness, abdominal or reproductive organ surgery, recreational drug use, and medications can affect fertility. Physical examination may detect testicular irregularities (e.g., varicocele, absence of vas deferens, tumor), evidence of hormonal disorders (e.g., underdeveloped reproductive organs, enlarged breast tissue), or evidence of testosterone deficiency.
Assessing reproductive-fertility history is important; specialists typically inquire about the following:
- Early puberty (may result from hormonal disorder)
- Late puberty (may result from Kallmann's syndrome)
- Previous pregnancy
- Sexual intercourse timing (understanding ovulation)
- STDs (can cause scarring, obstruction)
- Use of lubricants (may kill sperm)
A semen analysis, usually performed by a fertility specialist, is used to examine the entire ejaculate, because seminal fluid can affect sperm function and movement. Generally, three semen samples are taken at different times to account for variables such as temperature and error. Most specialists prefer three samples that differ no more than 20% from one another before proceeding with diagnosis.
Six sperm factors are analyzed in semen analysis:
- Concentration (sperm/milliliter; cc)
- Morphology (sperm shape; normal structure associated with sperm health)
- Motility (or mobility; % sperm movement)
- Standard semen fluid test (thickness, color)
- Total motile count (total number of moving sperm)
- Volume (total volume of ejaculate)
Azoospermia is the absence of sperm in the semen. Men with normal reproductive tracts and hormone systems can have azoospermia due to a lack of sperm-producing tissue in the testes or an obstruction. Obstructions can be viewed with x-ray. The World Health Organization has established criteria for normal sperm concentration, morphology, and motility. Total motile sperm count, which should be about 40 million, is calculated by multiplying volume by concentration by motility.
The semen fluid test looks at factors that may impede sperm performance. Abnormally thick semen may cause sperm to swim more slowly through cervical mucus, obstructing fertilization. Abnormal sperm shape (i.e., disfigured or multiple heads or tails) usually indicates poor sperm health. Infertility is likely if 60% or more of sperm in semen is abnormally shaped.
Other tests are concerned specifically with sperm's ability to swim through cervical mucus and bind to and penetrate an egg. The postcoital Sims-Huhmer, or sperm-mucus interaction test, examines whether the sperm are able to swim through the female reproductive tract. This ability is referred to as forward progression. In the middle of the menstrual cycle, the cervical mucus becomes watery. Intercourse is recommended during this time, followed, the next day, with an inspection of the mucus to determine if
- enough semen was delivered to the cervix;
- sperm are healthy and do not show large numbers of clumped, motionless, or dead cells; and
- sperm are swimming energetically through the cervical mucus./li>
The sperm penetration assay (SPA), or sperm-oocyte interaction test, examines the ability of sperm to penetrate the egg by combining it with a hamster egg. The immunobead test looks at semen for the presence of antibodies that damage sperm.
Post-ejaculation urinalysis may identify diseases that affect fertility, such as kidney disease, diabetes, and repeated urinary tract infection (UTI). Blood tests identify disorders that impair testosterone and sperm production.