What Causes Male Infertility?
It’s a touchy subject: Infertility is defined as the inability to achieve a pregnancy after one year or more of frequent unprotected sexual intercourse. Not only is this problem more common than you might think, newer research shows that male issues are at least partially to blame for one-third and even up to one-half of cases in which U.S. couples are unable to get pregnant.
Some causes of male infertility can be treated, and others may only be temporary and disappear over time. "A full cycle of sperm production is about three months long," explains physician Tobias Kohler, MD, associate professor at Southern Illinois University School of Medicine in Springfield, Ill. "Many things can damage sperm within that time frame, such as excessive heat, but that won’t cause permanent damage."
Causes of Male Infertility
One cause of male infertility is thought to be related to a condition called varicocele, in which veins in the scrotum become dilated. Varicocele is very common, and many men with varicocele do not have fertility problems, so the relationship to infertility may be complex.
“About 40 percent of men with infertility will also have this condition,” says Kohler. Though not everyone who suffers from varicoceles will have problems with fertility, it’s a “progressive defect,” meaning fertility issues may arise over the years.
Testosterone production is essential for producing healthy sperm, so low testosterone is another factor in male infertility. Some portion of male infertility is related to a congenital hormone disorder, but hormones and sperm production can also be affected by illicit drug use.
Marijuana, narcotics and anabolic steroids can prevent different aspects of male fertility. Steroids in particular are harmful in that they trick the brain into thinking the testicles are producing too much testosterone, and subsequently, the testicles are essentially shut down. Without any hormone signals to continue with normal function, the testicles stop producing fresh sperm and shrink down to a fraction of their normal size.
Other factors affecting male fertility include:
- Abnormally shaped sperm;
- Sperm that cannot swim or obstacles that interfere with release of sperm;
- Injuries; and
- Underlying health issues like diabetes.
What Increases Male Infertility?
If varicoceles are the issue, surgery can help. For other causes of sperm quality and quantity, reevaluate your lifestyle choices and consider applying healthier changes. For example, sticking to a diet that is rich in fruits and vegetables, along with taking daily multivitamins, is a good place to start.
Don’t smoke cigarettes or use marijuana, which has been shown to decrease sperm count. Neither caffeine nor alcohol has been proven to have a negative effect on sperm, but moderation is still a good idea, according to several studies presented at the International Federation of Fertility Societies and the American Society for Reproductive Medicine (ASRM) meeting.
Another healthy option is exercise. ASRM research confirms that higher levels of physical activity are directly associated with higher sperm concentrations.
If you and your partner have been trying to get pregnant for a year without success, or for at least six months if you (or your partner) is over age 35, it may be time for both of you to be evaluated for potential infertility issues.
For males, this involves a simple semen analysis after a period of about two to three days without an ejaculation. The sample will be screened for sperm count, the shape of the sperm cells and their motility, or how well they swim. (In men, hormonal assessment for infertility includes analysis of serum testosterone, luteinizing hormone and follicle-stimulating hormones.
Incidentally, a healthy sperm count ranges between 20 and 150 million per millimeter, say experts, and at least 60 percent of sperm should have normal shape and show normal forward movement.
Kohler T., MD, associate professor at Southern Illinois University School of Medicine. http://www.siumed.edu/. Interviewed January 2014.
American Society for Reproductive Medicine. “Impact of Caffeine, Alcohol and Exercise on Sperm Quality.” October 2013. https://www.asrm.org/Impact_of_Caffeine_Alcohol_and_Exercise_on_Sperm_Quality/. Accessed February 2014.
FamilyDoctor.org. “Male Infertility.” Updated March 2014. http://familydoctor.org/familydoctor/en/diseases-conditions/male-infertility.html. Accessed March 2014.
MedlinePlus. “Semen Analysis.” Updated April 2012. http://www.nlm.nih.gov/medlineplus/ency/article/003627.htm. Accessed January 2014.
Weidner W., Pilatz A., Altinkilic B., et al. "Andrology: Varicocele: an Update". Der Urologe. 2010; 49 (supplement 1); pages 163-165. http://www.ncbi.nlm.nih.gov/pubmed/20812044. Accessed February 2014.