Fertility declining among men of north India. And thanks to tight jeans. So says a study conducted by the All India Institute of Medical Sciences (AIIMS), New Delhi.
A ten-year study by the premier medical institution actually reveals a dramatic fall in fertility, reports say.
The sperm count of a normal adult male in India has plunged to around 20 million per ml as against 60 million per ml around 30 years ago.
And this relatively swift decline in sperm count is being linked to habits which expose the scrotum to higher-than-normal temperatures.
In all a thousand men from the northern parts of India were covered by the AIIMS survey funded by the Indian Council of Medical Research (ICMR).
Lifestyle factors like tight clothing, hot tub dips and long visits to the sauna, pesticide exposure due to intensive gardening or farming as well as increased obesity rates have been cited as the major causes for the decreasing sperm count.
AIIMS associate professor Dr Rima Dada who led the survey says that when the groins are encased in tight denim trousers, the testicles are pushed back and subjected to a higher temperature than otherwise would be the case.
Besides, sudden weight gain leads to increase in abdominal fat, which also leads to high testicular temperature. Stress is another factor that lowers the sperm count, she says.
A State University of New York study three years ago had showed how laptops could damage fertility.
Dr. Yefim Sheynkin, an associate professor of urology at the University had led the study of the effect of heat from the computers on the genital region.
Keeping a laptop on the lap for an hour could raise scrotal temperatures by more than 2.5 degrees Celsius, enough to affect fertility significantly, he had said then.
But Sondheimer, a professor of obstetrics and gynecology at the University of Pennsylvania Medical Center, said there was little for men to worry about. "We've known for a long time that anything that warms the testicles lowers the sperm count, but whether this translates into infertility is not clear," he said. "Most likely it does not lead to infertility. We don't translate this information into clinical practice."
Previous studies have raised alarms about other factors that could affect male fertility by raising scrotal temperatures. French researchers reported in 2000 that driving a car for two hours raised the temperature by more than 2 degrees Celsius. A report from doctors in Kiel, Germany, that same year warned about the possible danger of plastic-lined disposable diapers, which were found to raise temperatures more than cotton diapers.