NUDITY AND HEALTH
Study Shows Hot Tubs Hurt Male Fertility
03/02/2007, San Francisco, CA — Exposure to hot baths or hot tubs can lead to male infertility, but the effects can sometimes be reversible, according to a new study led by a University of California, San Francisco urologist.
It has been believed for decades that wet heat exposure is bad for fertility, as an old wives' tale, but this effect has rarely been documented,
said Paul J. Turek, MD, lead investigator who is a professor in the UCSF Department of Urology and director of the UCSF Male Reproductive Health Center. We now have actual evidence to show patients that these recreational activities are a real risk factor for male Infertility.
Results from a three-year study analyzing data from infertile men who had been repeatedly exposed to high water temperatures through hot tubs, Jacuzzis or hot baths are reported in the March-April 2007 issue of International Braz J Urol,
the official journal of the Brazilian Society of Urology. Study findings are available online at www.brazjurol.com.br.
Although this was only a pilot study, Turek said, these activities can be comfortably added to that list of lifestyle recommendations and ‘things to avoid’ as men attempt to conceive.
Dry heat exposure, for instance, as presented with fevers or through applied external heat, is a well-documented cause of impaired sperm production in both animals and humans, according to Turek. This is the first published study to show that total body exposure to wet heat can also impair both sperm production and motility. Study findings also showed that the negative effect of this exposure was reversible in nearly half of the infertile men who discontinued the practice.
The ASRM estimates that 85 percent to 90 percent of infertility cases can be effectively treated with drug therapy or surgical procedures. Less than 3 percent require advanced reproductive technologies, such as in vitro fertilization.
The study's patients were identified on the basis of repeated exposure to wet heat and were asked to cease that exposure for three or more months. Forty-five percent of the patients responded favorably to the cessation of heat exposure and had a mean increase in total motile sperm counts of 491% percent after three to six months.
Of the 55% of the patients who did not see an increase in sperm count or motility, tobacco use emerged as a possible differentiating factor. 85% of those patients were chronic tobacco users with a significant smoking history, in contrast to only 20% occasional smokers in the responder group. No other potential gonadotoxic factors — harmful to the male gonad — were identified.
For the purposes of this study, wet heat exposure was defined as the immersion of the body in a hot tub, heated Jacuzzi or bath at a temperature warmer than body temperature for 30 minutes or more per week for at least three months prior to participation in the study. Patients were excluded from the study if they had received infertility treatments in the previous year, or if female infertility was a co-existing factor.
The only previously published study to examine this link was performed in 1965, according to the research paper. In that study, a group of men were exposed to direct scrotal wet heat for 30 minutes on six alternating days. The findings showed a temporary decline in sperm production during the treatments, but there were no details of semen quality before and after the study. An unpublished Swiss study in the 1940s had also linked wet heat to temporary male infertility. Concern about wet heat effects on infertility crosses many cultures, Turek said, citing a centuries-old practice in Japan of barring childless men from conducting business deals in hot tubs, due to its believed effect on fertility.
According to the ASRM study, wearing tight undershorts that hold the testicles too close to the body can also keep the testicles too hot to produce an adequate number of healthy sperm. Too much smoking, drug abuse, alcohol, or even stress may also make infertility problems worse.
The study recommends that men who want to avoid infertility should not use hot tubs or saunas. Instead the patient may be told to wear boxer shorts rather than tight underwear to keep the testicles cooler. He may also be told to bathe his testicles in cold water 2 times a day.
ASRM also suggests that couples plan intercourse every 36 hours during the woman's fertile period. This allows more sperm to develop increasing your chance of getting your partner pregnant.
However, waiting too long (sex less often than once every seven days) also can decrease the amount of sperm one has. If none of these methods get the sperm count back up to normal levels, doctors may recommend certain medicine be used to treat the infertility problem, such as antibiotics or chemotherapy. Sometimes a sex therapist is brought to assist with related problems, such as impotence or premature ejaculation.