target="_blank" rel="nofollow" href="#fb3_img_img_f3ba5a72-5a5b-569e-b989-13683c6f973b.png" alt="Warning"/> Anything that raises the temperature of a man’s testicles can decrease sperm production and motility. Hot tubs, saunas, steam rooms, and tight underwear are out for men! Well … maybe not out altogether.
It seems that the evidence for this belief is derived from a study published in 2007. Searching for other studies failed to identify any. Even the study authors cautioned that their study was a pilot study and suggested further research, but none was ever reported in searchable databases. The study looked at 11 males, asked them to stop using the hot tub, and found that 5 out of the 6 who did stop had an improvement in the motility of the semen analysis. The study did not attempt to determine whether this change increased the chance for conception. Based upon this extraordinarily weak evidence, it is hard to make a recommendation about hot tubs and fertility. A 1996 study looked at using a scrotal cooling device and infertility. The study had 25 subjects, and 16 of the 25 men had an improvement in the semen while 6 achieved a pregnancy. So admittedly, constantly heating the testicles is probably not a good idea, but there is very little evidence that heat exposure affects male fertility. Finally, a 1998 study looked at the influence of boxer shorts on male fertility and guess what? No effect! So, boxers or briefs or commando are okay.
Can the female join her mate now that he has been cleared for hot tub use — perhaps less frequently? The body has incredible temperature regulatory systems to prevent the core body temperature from rising. As a graduate student, Dr. R supplemented his income by being a subject for studies looking at the effect of heat and humidity on human physiology. The subjects walked on treadmills in an environmental chamber where the heat and humidity could be controlled. As the temperature and humidity were increased, the body’s core temperature began to rise. A 1 degree Centigrade rise was enough to absolutely drive the subject to get out of the chamber and cool down, and no amount of threats or money could stop the subjects (meaning Dr. R). The ovaries reside well within the human body and thus are kept at core temperature. No amount of hot tub use can cause a significant rise in the woman’s core temperature, and if for some reason it does start to rise, no amount of encouragement from her partner will keep her in that tub — sorry, guys.
Balancing the yin and yang of exercise
So your partner decided to work out stress by bicycling or playing rugby. This exercise should be a good thing, right? Wrong! Prolonged cycling can cause damage to the groin from constant pressure of the bike seat, and contact sports can lead to injury to the testicles and can damage sperm production. The emphasis here is on prolonged cycling, not recreational cycling. However, most studies evaluated the effect of cycling on semen parameters and not on reducing the fertility rate. For males with a normal semen analysis, exercise (especially recreational exercise) does not seem to alter the man’s fertility potential. For males with mildly abnormal semen parameters, reducing exercising levels, especially cycling, may have a beneficial effect.
Women who exercise heavily may find that their periods have stopped. This condition is called amenorrhea (we get into this in Chapter 11) and is common among women who are very thin and exercise daily. Obviously, you can’t get pregnant if you’re not having periods; you’re not developing eggs. Particularly concerning is the triad of no periods, heavy exercise, and bulimia. This triad requires treatment by a physician. So what can you both do to reduce stress that won’t cause fertility problems? Exercise in moderation is fine — for both of you!
Dumping the douche
Avoiding toxins at home and away
Think about substances that you’re exposed to at work. For instance, if you’re a home remodeler, bridge painter, welder, or solderer, you may be exposed to large amounts of lead. You run the same risk if you’re remodeling an old house and scraping old paint off the walls. Lead exposure in men has been linked to low sperm count and decreased motility of sperm. In women, lead exposure may cause low birth weight in babies, high blood pressure during pregnancy, damage to the baby’s nervous system, and developmental delays.
Heavy, exertional work can lead to reduced sperm counts, but there is little evidence about the effect of this on actual fertility rates.
The advent of OSHA (the federal Occupational Health and Safety Agency) has provided safe work environments for almost all occupations. Since this is true, it is hard to imagine that there are strong negative influences on fertility rates based upon occupations. In fact, even though OSHA lists a few known toxins that could affect fertility (nitrous oxide, lead, jet fuel, and a variety of pesticides), it clearly states that these substances may not affect all workers, or all workers in the same way.
There are a few studies that identify some environmental toxins that may (emphasis on the possibility, not the probability) impact a person’s infertility. These include hexachlorocyclohexane, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), some pesticides, and ingested heavy metals (mercury and lead).
Making the connection between stress and fertility
Can stress keep you from getting pregnant? First of all, what is stress? One Google definition is “a state of mental or emotional strain or tension resulting from adverse or very demanding circumstances.” However, a key factor resulting in elevated stress is the person’s reaction to a situation. Some circumstances create more stress for some people than for other people.
Dr. R: I remember one patient who had a very achievement-oriented, high-powered North Shore Chicago–type job. She found not being able to conceive at her command almost intolerable since for most everything else she had tried she was successful. Somehow, she was convinced by well-meaning friends and family that if she would only relax, she would become pregnant. So, she quit her job and stayed at home eating well and exercising. Since she was not working, she could devote every waking moment to her quest. After about two weeks of “rest” she was climbing the walls with boredom and her stress
