Infertility
Infertility is the inability to conceive after at least one year of unprotected intercourse. Since most people are able to conceive within this time, physicians recommend that couples unable to do so be assessed for fertility problems.
In men, hormone disorders, illness, reproductive anatomy trauma and obstruction, and sexual dysfunction can temporarily or permanently affect sperm and prevent conception. Some disorders become more difficult to treat the longer they persist without treatment.
Sperm development (spermatogenesis) takes place in the ducts (seminiferous tubules) of the testes. Cell division produces mature sperm cells (spermatoza) that contain one-half of a man’s genetic code. Each spermatogenesis cycle consists of six stages and takes about 16 days to complete. Approximately five cycles are needed to produce one mature sperm. Energy-generating organelles (mitochondria) inside each sperm power its tail (flegellum) so that it can swim to the female egg once inside the vagina. Sperm development is ultimately controlled by the endocrine (hormonal) system that comprises the hypothalamic-pituitary-gonadal axis.
According to the National Institutes of Health, male infertility is involved in approximately 40% of the 2.6 million infertile married couples in the United States. One-half of these men experience irreversible infertility and cannot father children, and a small number of these cases are caused by a treatable medical condition.
Symptoms
Common causes for male infertility are impaired sperm production, impaired sperm delivery, and testosterone deficiency (hyogonadism).
Infertility can result from a condition that is present at birth (congenital) or can develop later (acquired). Causes for infertility include the following:
- Chemotherapy
- Defect or obstruction in the reproductive system (e.g., cryptorchidism, anorchism)
- Disease (e.g., cystic fibrosis, sickle cell anemia, sexually transmitted disease [STD])
- Hormone dysfunction (caused by disorder in the hypothalamic-pituitary-gonadal axis)
- Infection (e.g., tersticular trauma)
- Medications (e.g., to treat high blood pressure, arthritis)
- Metabolic disorders such as hemochromatosis (affects how the body uses and stores iron)
- Retrograde ejaculation (i.e., condition in which semen flows backwards into the bladder during ejaculation)
- Systemic disease (e.g., high fever, infection, kidney disease)
- Testicular cancer
- Varicocele
Retrograde ejaculation occurs when impairment of the muscles or nerves of the bladder neck prohibit it from closing during ejaculation. It may result from bladder surgery, a congenital defect in the urathra or bladder, or disease that affects the nervous system. Diminished or “dry” ejaculation and cloudy urine after ejaculation may be signs of this condition.
Testosterone deficiency – Hypogonadism may be present at birth (congenital) or may develop later (acquired). Causes of the conditon are classified according to their location along the hypothalamic-pituitary-gonadal axis:
- Primary, disruption in the testicles
- Secondary, disruption in the pituitary gland
- Tertiary, disruption in the hypothalamus
The most common congenital cause is Klinefelter syndrome. This condition, which is caused by an extra X chromosome, results in infertility, parse facial and body hair, abnormal breast enlargement (gynocomastia), and smaller than normal testes.
Other congenital causes include absence of the testes (anorchism; may also be acquired) and failure of testicles to descend into scrotum (cryporchidism).
Acquired causes for testosterone deficiency include the following:
- Chemotherapy
- Damage to the pituitary gland, hypothalamus, or testes
- Glandular malformation
- Head trauma affecting the hypothalamus
- Infection (e.g., meningitis, syphillis, mumps)
- Isolated LH deficiency (e.g., fertile eunuch syndrome)
- Radiation
- Testicular trauma
- Tumors of the pituitary gland, hypothalamus, or testicles
Diagnosis
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., vericocele, 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 hisotry 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)
- STD’s (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 intereaction 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.
Treatments
At least one-half of male fertility problems can be treated so that conception is possible. There are three catagories of treatment for male infertility:
- Assisted reproduction
- Drug therapy
- Surgery
Assisted reproduction therapy includes methods to improve erectile dysfunction, induce ejaculation, obtain sperm and inseminate the egg.
Electroejaculation – This procedure can be used to produce ejaculation when neurological dysfunction prevents it. An electrical rectal probe generates a current that stimulates nerves and induces ejaculation; semen dribbles out through the urethra and is collected. retrograde ejaculation is associated with the procedure and sodium bicarbonate is usually taken the day before to make the urine alkaline (nonacidic) and nondetrimental to sperm. Candidates for electroejaculation include men who have undergone testis removal (orchiectomy), retoperitoneal lymph node dissection, and those with spinal cord injuries.
Sperm retrieval – This technique is used to obtain sperm from the testes or epididymis when obstruction, congenital absence of the vas deferens, failed vasectomy reversal, or inadequate sperm production causes azoospermia. Using a technique called micro epididymal sperm aspiration (MESA), a surgeon makes an incision in the scrotum and gathers sperm from the epididymis, the elongated, coiled duct that provides for the maturation, storage, and passage of sperm from the testes. Percutaneous epididymal sperm aspiration (PESA, or fine needle aspiration) is similar to MESA but does not involve microsurgey. A physician uses a needle to penetrate the scrotum and epididymis and draws sperm into a syringe. Testicular sperm extraction (TESE), the removal of a small amount of testicular tissue, is used to retrieve sperm from men with impaired sperm production, or when MESA fails.
