But infertility specialist Dr. Marcelo J. Barrionuevo of IVF Florida Reproductive Fertility Associates reminds us of a study that younger men, especially, should be aware of.
A small study by Yefim Sheynkin of State University of New York in Stony Brook suggested that laptop computers, well, shouldn't be used on men's laps.
The study, released in December 2004, proposed that laptop computers can pose a long-term threat to the fertility of young men who use them by raising temperatures in the genital area that might slow or stop sperm formation.
Sources such as WebMD reported that researchers studied 29 healthy young men, 21 to 35, for two one-hour sessions in a climate-controlled room. After having their body temperatures taken and standing in the room for 15 minutes to adjust to the room's temperature, they sat down and were given working or nonworking laptop computers.
The researchers used two brands of computers, which weren't identified in the study. The men's scrotal temperature was recorded every three minutes. The temperature on the bottom of the working computers was also monitored. Scrotal temperature rose with the working and nonworking computers. However, the working laptops produced a greater increase in scrotal temperature -- around a 5 degrees Fahrenheit increase. Participants without working laptops had a scrotal temperature increase of about 3 to 4 degrees Fahrenheit.
Some of the increase was attributed to the fact that thighs were held tightly together to balance the laptops. That can increase scrotal temperature, as well. While the researchers weren't concluding definitely that higher scrotal temperatures could cause reproductive problems, they did feel confident in concluding that putting the appropriately named "laptop" on a guy's lap can reduce sperm count. They coined a good expression for the condition: scrotal hyperthermia.
Barrionuevo notes that there's not enough conclusive evidence yet to sound an alarm to boys and young men, but he nevertheless suggests keeping the laptop on the desk. Those, however, who may be looking for a novel form of contraception might consider an increase in their laptop time. (Researchers, however, didn't address that issue.)