Prevalence of male infertility.
Infertility is defined as having unprotected regular intercourse for a period of one year without conceiving. Approximately 1 in 8 couples in the United States are having difficulty with infertility. Approximately 40% of infertility is due to a male factor. Some male factor infertility can be treated, but the majority of cases we are forced to work with the “numbers” produced. Suffice it to say, if an individual has any sperm he has the option of having his own genetic child.
Causes of male infertility.
- A lack of healthy sperm producing cells in the testicle, spermatogonia cells.
- A lack of hormone production by the pituitary gland stimulating sperm production.
- An obstructive problem with the ducts conveying sperm from the testicle to the penis.
Male infertility diagnosis.
The primary method of determining a male factor is through a semen analysis. If an abnormality is identified it is important to repeat an analysis in approximately six weeks (it takes approximately six weeks to make sperm). When collecting a semen analysis it is important to abstain for at least 2-3 days prior to collection, otherwise volume and counts are likely to be low. Abstaining for an excessive length of time may result in poor motility and or poor morphology due to “old sperm”. When evaluating the semen it is important not to wait more than approximately one hour, evaluation should be done after complete liquefaction. It is important to keep the specimen at or near body temperature while liquefaction occurs. The primary semen parameters analyzed are:
Count – the number of sperm in a milliliter of semen. A normal concentration should be at least 15 million/mL. The complete collection should contain 30 million motile sperm.
Motility – at least 40% of sperm should show progressive motility, ideally the more linear movement is, the better (greater likelihood of reaching the egg in the tube).
Morphology or shape of sperm – at least 15% of the sperm should show normal shape.
The Florida Institute for Reproductive Medicine uses only strict, Kruger criteria to evaluate morphology, this criteria has been shown to be highly reproducible and predictive of fertilization, in vitro. Other semen parameters that are also important are the number of white blood cells (indicative of a genitourinary infection) as well as assessment of antisperm antibodies (antisperm antibodies can prevent binding of the sperm to the egg or cause sperm to stick together).
When looking at the semen analysis what the reproductive medicine specialists is really assessing is the total number of normal, motile sperm free of antibodies. This is the number of sperm that are believed capable of fertilizing an egg. While there is no consensus of what this number is, ranges are likely between 15-40 million.
Physical exam, endocrine and genetic testing.
In addition to the semen analysis if a patient has a sperm concentration of 5 million or less physical exam, endocrine and genetic evaluations should be obtained. The physical exam centers on evaluation of the size and consistency of the testicles, the presence of intact ducts, the vas deferens, that allow sperm to pass from the testicle to the urethra of the penis. If the vas deferens is absent testing for cystic fibrosis is indicated as almost 80% of such individuals will be carriers for cystic fibrosis. Gonadotropin hormones, the hormones that stimulate sperm production, along with thyroid and prolactin levels that can affect gonadotropin production are important to assess. Genetic studies, Y-deletion and karyotypes should be obtained to determine if there is a genetic reason for the low count.
Male infertility treatment.
Elevated gonadotropin levels are indicative of significant end organ failure, i.e., a lack of healthy producing sperm cells. If an anatomic problem is identified consultation with an urologist knowledgeable in reproductive reconstructive surgery is appropriate. Depending on the female partner’s age, i.e., her window of fertility, artificial insemination or ICSI/IVF may be more appropriate treatments than surgery. If there is a hormonal reason for a low count, antiestrogen or gonadotropin therapy is frequently prescribed – treatment must be for at least 4-5 months. It may be that counts are not increased to normal, but at least to the point where a simple less expensive therapy, i.e., artificial insemination may be an option. Men are frequently put on the antiestrogen, i.e., clomiphene citrate, without doing an endocrine evaluation, the great majority of these individuals have normal or elevated hormone levels and will not benefit from treatment.
If a genetic reason for a poor count is identified, couples may consider using donor sperm or elect to proceed with IVF with preembryo genetic testing (biopsy and testing of cells) to avoid genetic transmission to an offspring.
For a mild male factor most often artificial insemination in conjunction with superovulation (inducing multiple eggs to release) is initially recommended. Artificial insemination increases approximately ten-fold the number of sperm reaching the egg(s) in tube. Generally if this treatment is going to be successful it is within four attempts. With a severe male factor IVF with intracytoplasmic sperm injection (ICSI) is usually recommended. ICSI/IVF is often recommended with high levels of antisperm antibody binding particularly when binding is to the head of the sperm, i.e., we do not have good treatments to lower antisperm antibodies.
Males with no sperm, azoospermia, can have their own genetic children.
Causes for lack of sperm (azoospermia) in the ejaculate fall into two categories, obstruction and production problems. In cases of obstructive azoospermia we can retrieve sperm from the epididymis, microscopic epididymal sperm extraction (collecting storage tubules off the testicles) or testicle, testicular sperm extraction, in approximately 90-95% of cases. With a production problem we are able to obtain sperm in 50-60% of cases. At the Florida Institute for Reproductive Medicine we use micro-testicular sperm extraction (removal of tissue under high magnification) to improve the chances for obtaining sperm by identifying dilated sperm containing tubules.
Men who have evidence of end organ failure and who do not have sperm identified in testicular tissue are likely to require donor sperm. Cloning sperm from other cells has resulted in the birth of non human mammals. Health data on these offspring is still lacking – but this may be an option for truly azoospermia males in the future.