A team of German researchers has found that disposable nappies increase the temperature of baby boys' testicles, a finding which they say could have implications for male fertility.
The study, published in the latest issue of the Archives of Diseases in Childhood, shows that compared to cotton nappies, plastic-lined nappies increase the scrotal temperature by an average of one degree Celsius. The Kiel University scientists measured the scrotal skin temperature of 48 boys ranging from newborn to four year-olds, during both the day and night. Such an increase may affect the healthy functioning of the testicles in later life and lead to lower sperm counts in adulthood, the paper concludes. The authors hypothesise that the increasing popularity of disposable nappies during the past 25 years could be to blame for the declining sperm quality and increased testicular cancer rates in some industrialised countries.
The results were swiftly disputed by Peter Stephenson, director general of the Absorbent Hygiene Products Manufacturers Association. He said the study was 'scientifically flawed', and that the conclusions were irresponsible, inappropriate and unreliable. He pointed out that some studies of male fertility suggest that sperm counts began to fall before the second world war, when disposable nappies had not been invented.
UK fertility expert Dr Simon Fishel said that the theory was quite sensible, and he was not totally surprised by it. However, paediatrician Dr Louise Parker said the speculation that disposable nappies may have played a role in the increase in testicular cancer or decreased sperm count was 'completely inappropriate'.