Male Factor Infertility
Male factor infertility is quite common, contributing to 40% of infertility diagnoses. Treatment is designed around the particular type of problem and can be remarkably effective. For those with male factor infertility, the initial course of action is to review personal health habits. Stress, poor diet, and alcohol use have all been correlated with male factor infertility. Alcohol use, in particular, has been shown to have a dose-related effect on sperm; the more one drinks, the poorer the reproductive outcome. High temperature exposure from hot tubs or hot baths (immersion in hot water), or heavy exercise, particularly bicycle riding, have been correlated with male factor infertility as well. Resting a laptop computer on one's lap has also been implicated in raising testicular temperature. Diagnosis of male factor infertility starts with a semen analysis. The semen analysis should be performed on an ejaculated sample collected on at least two occasions 2-7 days following abstention from sexual activity. Measurement of the sperm count, motility, and volume can reveal production problems as insufficient or poor quality sperm are released from the testes. Table 1 lists the standards for assessing a semen analysis (Source: The World Health Organization, 1992).
Additional tests to evaluate sperm quality include the detailed or Krueger morphology. This entails viewing individual sperm cells under a high-powered microscope. This is a strict test that reveals abnormalities in the shape and size of the sperm heads, mid-pieces, and tails. A normal morphology is present when over 14% of sperm are normal.
Survival of the sperm on extended testing is also a useful diagnostic test. The sperm survival test, or SST, is a method for testing the lifespan of the sperm. At 24 hours, sperm survival should be over 40% (i.e. 40% of the sperm sample should survive); conversely, lower survival rates correspond to lower pregnancy rates.
Additional testing for male factor infertility includes a physical exam, blood tests for FSH, prolactin, and testosterone, and an ultrasonography of the collecting tubes of the male reproductive system. In some cases, an assessment of DNA fragmentation can give an index of sperm quality as well.
One condition we encounter at our clinic is azoospermia, which is the absence of sperm in the ejaculate. This can occur from birth defects, injury or infection, or rare endocrine abnormalities. In azoospermia, a high FSH level indicates testicular failure. Insufficient levels of testicular hormones lead to an increase in the release of pituitary gland FSH to compensate. High levels of testicular hormones are often accompanied by testicular atrophy (small testicles). Testicular biopsy may confirm the clinical findings.
Men with testicular failure (and very low sperm counts) should be tested for Y-chromosome microdeletions and abnormal karyotypes, or chromosomal count. Microdeletions may be transmitted to offspring, resulting in fertility problems for boys born after treatment.
The most common abnormal karyotype is Klinefelter Syndrome, where the male has three or more sex chromosomes, instead of the normal two. Such chromosomal defects can have effects on children born after treatment, and men should receive genetic counseling and risk assessment prior to infertility treatment. Men with testicular failure may still have partial sperm production. Detailed assessment with microscopic surgery may detect a sufficient amount of sperm to use with in vitro fertilization (IVF).
Obstruction is another type of male factor infertility, as potentially normal sperm cannot move from the testes to the ejaculate. Men with a normal FSH may have an obstruction in the vas deferens or any of the other collecting tubes that gather sperm from the testes. Men with congenital absence of the vas deferens (CBAVD) may be carriers of cystic fibrosis, and should be tested. Surgical obstruction, or vasectomy, is readily repaired. Microsurgical techniques, and an experienced surgeon, will increase success rates. The procedure may be attempted for many years after an initial vasectomy. More unusual obstructions can result after infection of the epididymis. Ejaculatory duct obstruction can be treated with a cystoscopic procedure. Obstructions can sometimes be repaired, but often a simple needle aspiration procedure (percutaneous epididymal sperm aspiration, PESA) will yield enough sperm to achieve fertilization with IVF.
The key treatment when working with low sperm numbers, whether in the ejaculate or obtained by needle aspiration or biopsy, is to perform in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). ICSI is when a highly trained embryologist uses micromanipulators to inject an individual sperm into an egg, optimizing for fertilization.
ICSI has become a common procedure, resulting in many pregnancies worldwide for men that otherwise could not have children. Sperm with a variety of abnormalities, ranging from low counts, to extremely low motilities, can be suitable for use. The DNA of the sperm is tightly compacted in ways that protect it from injury, even when the other components of the sperm do not function well. Injecting the sperm into the egg can bypass the barriers separating sperm and egg.
Another condition we encounter which can lead to abnormal sperm parameters is the presence of a varicocele. A varicocele is an enlarged vein along the upper part of the scrotum. The blood carried in these veins may elevate the scrotal temperature, and possibly carry toxic materials into the testicle, affecting sperm production. Only varicoceles that are palpable are thought to contribute to infertility. Ultrasound is sometimes used to confirm an uncertain diagnosis, but there is doubt whether subclinical varicoceles are associated with infertility. Varicoceles can be repaired, or various fertility treatments attempted, including sperm wash and insemination, and in vitro fertilization. The decision of treatment depends on both male and female factors, such as age, tubal disease, and ovulation disorders.
-- Philip Chenette, MD