Men involved in the new study, published in the journal Human Reproduction, were aged between 18 and 65. Scientists believe bigger waistlines, poor diets and even exposure to pollution could be behind the worrying trend. Sperm counts generally decline in age, peaking when a man turns 17 and remaining high until their 40s.Ī normal sperm count is considered to be any amount greater than 15million of sperm per millilitre of semen.īut levels among men have been plunging overall since the 1970s, studies in Europe, North America and Australia show.
