About 15% of couples do not achieve a pregnancy after one year of regular unprotected intercourse.
Factors associated with the man contribute in 50% of these cases (20% due to the man alone and 30% due to a combination of factors from both the man and woman). Fertile couples have about 20% per cycle conception rate while infertile couples have about 2% per cycle conception rate.
Causes and Risk Factors
Male infertility may be due to many different causes. The potential causes can be grouped into three categories: pre-testicular (disrupted signaling to the testicle, such as from a hormone imbalance), testicular (a problem within the testicle itself, such as a genetic abnormality), and post-testicular (some blockage preventing sperm release, such as a prior vasectomy). No specific cause is identified in about 25% of cases. The most common cause (35% of cases) of male infertility is an enlargement of the vein draining the left testicle called a varicocele, which probably causes a disruption in sperm production by increasing the temperature in the scrotum.
When to Speak with a Urologist about Male Infertility
You and your partner should speak to a Urologist about male infertility if you have been trying unsuccessfully to conceive for one year. Also, if you have any reason to question your fertility as a couple you should speak to a Urologist. You do not have to wait 1 year to be evaluated. The American Society of Reproductive Medicine recommends simultaneous evaluation of both the man and the woman.
What to Expect when Seeking Treatment
In addition to a history and physical examination, initial assessment includes various diagnostic tests to determine the likely cause of male infertility and identify potential treatments to improve the likelihood of conception.
A scrotal ultrasound will quantify testicular size, examine surrounding structures and evaluate for other underlying abnormalities that have been associated with male infertility such as testicular tumors.
Blood work will determine if there are hormonal imbalances present in the hypothalamic-pituitary-gonadal axis involved in sperm production. These hormones include testosterone collected on morning laboratory draw, follicle stimulating hormone (FSH) and luteinizing hormone (LH).
A semen analysis will be obtained after 2-5 days of abstinence to evaluate for semen abnormalities (due to variability over time, at least two analyses are necessary). Multiple different parameters are assessed on a semen analysis including volume, sperm concentration, sperm count, sperm motility and sperm morphology (appearance).
The World Health Organization sets reference limits for semen parameters, which are currently in the 5th edition. The reference limits were determined at the 5th percentile level from a population of fertile men that conceived within 12 months of attempting to get pregnant (meaning that 95% of fertile men have parameters above that limit). According to WHO 5th edition, abnormal semen parameters are below: volume 1.5 ml, concentration 15 million/ml, count 39 million, motility 40%, morphology 4%.
Counseling regarding likelihood of conception based on a semen analysis is challenging particularly given the contribution of the female partner’s fertility. The only definitive finding on semen analysis is zero sperm on a sample that has been spun down and concentrated which indicates no possibility of a natural pregnancy. Increasing numbers of abnormal semen parameters (morphology, motility and concentration) increase the odds of infertility.
There are several universal recommendations to assist in conception. Living a healthy lifestyle incorporating diet, exercise, and avoidance of smoking will also aid reproductive health. Obesity and smoking are associated with impaired fertility. Heavy smokers have about 20% lower sperm counts than nonsmokers. Overweight patients have about 25% lower sperm counts than ideal weight individuals.
Store-bought lubricants for intercourse and even saliva used for lubrication should be avoided as these substances can impair sperm function. Vegetable oil, such as canola oil, can be used as an alternative that does not harm sperm.
Men should also avoid sources of wet heat, such as saunas and hot tubs, which harm sperm production.
Vitamins with antioxidant properties are thought to support sperm production and health. A Cochrane review of available randomized trials examining vitamin use suggests a 3-4 fold improvement in pregnancy and live birth rates with small improvements in sperm DNA damage, motility and concentration. The types of supplements varied in these trials, but the antioxidants with the best evidence include Coenzyme Q10 and Acetyl L-Carnitine
The couple should continue unprotected intercourse around the time of ovulation. If using a calendar on an iPhone application, then begin intercourse 2-3 days before predicted ovulation and have sex once every 48 hours until 3-4 days after predicted ovulation. If using LH strips, have sex on the day the strip turns positive, and then again on the following day.
Typically, 15 million moving sperm are necessary to have a reasonable chance of natural pregnancy. 5 million moving sperm are needed to perform intrauterine insemination (IUI); while only around 10 sperm are required for in vitro fertilization (IVF). IUI is a process where the male partner provides a semen sample according to the female partner’s ovulation, and the sample is then prepared and deposited into the uterus using a small catheter during a pelvic examination. IVF involves medications and a procedure to retrieve eggs from the female partner. The eggs and sperm are combined outside of the body, and the resulting embryos are monitored before select embryos can be transferred back into the female’s uterus.
For comparison, pregnancy rates in a healthy young couple are around 20% per cycle and about 15% per cycle with intrauterine insemination for couples with difficulty conceiving naturally. In vitro fertilization has live birth rates around 35-40% in one cycle for women less than 38 years old. After multiple rounds of cycles, pregnancy rates for IUI approach 40% per couple and live birth rates for IVF approach 80%. Of note, IUI can cost $500-1000 per cycle and IVF can cost $30,000-50,000 per cycle.
Pending the complete evaluation, certain medications or minor surgical procedures can be used to help increase the number or quality of sperm in the semen.
Certain medications may aid fertility by adjusting hormone levels. Sufficient levels of testosterone within the testicles are required for sperm production. Increasing testosterone in men with pre-existing normal testosterone levels does not improve fertility outcomes. No significant studies have investigated the use of medications to increase testosterone in men with low testosterone levels and low sperm parameters with the goal of improving fertility. But increasing testosterone in this setting may help sperm counts and improve energy and libido.
Various medications can increase testosterone without lowering sperm counts – it is important to note that taking direct testosterone supplements will further lower sperm counts.
Clomid (clomiphene citrate) modulates estrogen receptors in the brain and can cause the brain to send more signals (FSH and LH) to the testicles to produce sperm and testosterone. It is approved for use in women for female infertility but has been used off-label in men for over 45 years. Few side effects are reported but rare men complain of emotional changes and visual disturbances. In very rare instances or when taken for extended periods of time, Clomid may begin to have a counterproductive effect on hormones and may lower sperm counts.
Arimidex (anastrozole) blocks the breakdown of testosterone into estrogen which occurs predominantly in fatty tissue. Although approved for breast cancer indications, it is frequently used off-label in male infertility. This medication is particularly important for overweight men. Some men report joint pain and decreased libido.
Various surgical approaches can be used depending on the underlying cause of infertility. Those surgeries include repairing a varicocele, called a varicocelectomy, or different techniques of surgical sperm retrieval. Of note, sperm retrieved surgically can only be used to obtain a pregnancy through IVF because those sperm typically have not fully matured.
It takes approximately 3 months from when sperm form to when sperm can be ejaculated. Therefore, medication and surgical effects are not typically seen in semen analysis results for about 3 months.