Male Factor Infertility
What is male factor infertility?
The standard evaluation for infertile couples includes testing of the male partner. About 10% of infertility can be attributed to male factors only, while 35% of cases involve both male and female factors. Thus, almost half of all couples with infertility may have a male factor. While male factor infertility is most commonly due to problems with the sperm, it is also important to consider potential issues related to sexual behavior, such as erectile or ejaculatory dysfunction, or lack of sexual desire due to depression or medication use.
What causes male infertility?
Fertility in men requires normal functioning of the hypothalamus, the pituitary gland, and the testes. Male infertility can be caused by a variety of conditions; some of these can be corrected, while others cannot. Problems may exist in sperm production, delivery, or transport:
- 30-40% of cases are due to problems in the testes
- 10-20% are due to a blockage in the pathway that allows sperm to exit the testes during ejaculation (sometimes caused by previous infection)
- 1-2% of cases are due to problems in the pituitary or hypothalamus
- 40-50% of cases have no identifiable cause, even after evaluation
How is male infertility diagnosed?
The physician will perform a careful history and thorough physical exam, giving special attention to coexisting medical conditions, prescription or over-the-counter medications used, and environmental toxin exposures. Semen analysis is the most important test in an infertility evaluation. If the analysis is abnormal, the patient may be referred to a urologist. The semen analysis should ideally be performed after 2 to 3 days of abstinence (no ejaculations). Even if the male partner has fathered children in the past, it still very important to perform a semen analysis, since sperm production is sensitive to environmental toxins, and infection or other factors may affect the transport of sperm within the reproductive tract. Semen analysis focuses on three components:
- Concentration of sperm should be above 15 million per ml of semen. Despite millions of sperm that are ejaculated and deposited into the vagina at the time of sexual intercourse, only a few thousand are believed to actually migrate to the upper reproductive tract, to the area where the egg can be found.
- Motility refers to the percent of the sperm that are actually moving. This includes an assessment of their forward, progressive motion.
- Morphology refers to the shape or anatomy of the sperm cell. The shape correlates with the sperm’s fertilizing ability and appears to be a good measure of functional capacity.
How is male infertility treated?
Treatment for male infertility depends upon the underlying cause, and whether or not female factors also exist. Treatment often involves both the male and female partner.
Blockage of the reproductive tract prevents sperm from traveling from the testis to the ejaculatory duct. Blockage may be caused by previous infections or scarring from previous surgeries. In rare cases, some men are born without the necessary sperm transport structures (vas deferens). Treatments for blockage include:
- Surgery, performed by a urologist, may succeed in removing the blockage. If surgery does not resolve the problem, it is possible to remove sperm directly from the testis for use in an in-vitro fertilization (IVF) cycle.
- Vasectomy reversal: A vasectomy (male sterilization) is considered to be a type of blockage. Vasectomies can be reversed in up to 85% of cases, and more than 50% of couples can achieve pregnancy after vasectomy reversal.
Hypothalamic or pituitary deficiency: As in women, the brain regulates production of men’s reproductive hormones. Hormone production abnormalities, such as too little testosterone or too much estrogen, can inhibit the production and maturation of sperm.
- Sometimes treatment with human chorionic gonadotropin (hCG) and LH (Luteinizing hormone) or recombinant follicle stimulating hormone (rFSH) can supplement missing pituitary hormones to restore sperm production. The success rate for this type of therapy is high, but can require 6 months of treatment to see sperm cells in the semen. In many cases, 1 to 2 years of treatment is needed to achieve normal fertility.
Varicocele is a common, potentially correctable, cause of male infertility which results from a dilation of the veins (like a varicose vein) in the scrotum. This condition occurs in 15% of all men, and 40% of infertile men. It is associated with a low sperm count or abnormal sperm morphology (shape). The dilation of veins may cause a hostile environment for sperm production: higher temperature, poor oxygen supply, and/or poor blood flow in the testis can affect sperm.
- Varicocele can sometimes be treated surgically by tying off the abnormal veins; however, surgery does NOT always improve fertility and is usually only recommended if there is a large varicocele. Chronic varicoceles can cause irreversible damage that cannot be surgically treated.
- Varicoceles can also be treated using assisted reproductive technologies, such as IVF with intracytoplasmic sperm injection (ICSI).
Testicular Failure occurs when the sperm-producing structures of the testis have been severely damaged or are abnormal. This condition occurs in some men who have been exposed to chemotherapy or radiation, and can also result from injury to the testicles, testicular torsion, or undescended testes. Genetic abnormalities, such as Klinefelter syndrome are additional causes of testicular failure. Many forms cannot be reversed, and require either the use of assisted reproductive technology or the use of donor sperm.
Treatments for male and female partners:
Different treatments may be used depending upon whether the semen contains few sperm (oligozoospermia), no sperm (azoospermia), abnormally shaped sperm (teratozoospermia), and/or sperm with poor motility (asthenozoospermia).
- Intrauterine insemination is the best treatment for issues relating to sperm motility or concentration. The most motile sperm are concentrated and inserted into the female partner’s uterus at the time of ovulation. Intrauterine insemination can be combined with or used without treatment for the female partner.
- In vitro fertilization (IVF) is a commonly used technique for male tubal blockage and unexplained infertility. In an IVF cycle there are 2 methods of fertilizing the egg:
- Insemination: the eggs (removed from the female partner) are surrounded by a large number of sperm (50,000 per egg)
- Intra-cytoplasmic sperm injection (ICSI): a single sperm is injected into a single egg. If a couple has already decided to move on to IVF, and the semen analysis is abnormal, usually ICSI is recommended.
- Testicular extraction of sperm (TESE)is used in situations in which the man’s semen completely lacks sperm in the ejaculate. Sperm is removed directly from the testes either though a very small incision, or by using a needle to aspirate semen under local anesthesia. Sperm is not always found in this procedure, depending upon the cause of male infertility. If sperm is found and extracted, it is used for ICSI.