Sperm counts among Auckland sperm donors have halved in the past two decades - but experts are hesitant to conclude men's fertility is falling.
Average sperm counts for sperm donors at Auckland's Fertility Associates fell by just under 50 per cent between 1984 and 2003, from around 110 million to
60 million sperm per ml of semen.
John Peek, group operations manager at Auckland's Fertility Associates said sperm counts among donors did not necessarily reflect counts for the wider male population.
But Sian Harcourt, executive director of lobby group Fertility New Zealand, was less cautious about drawing conclusions.
"There does seem to be some indication that fertility has declined in the male population," she said.
Experts worldwide are divided over whether men's fertility is falling, but agree on the probable causes if it is.
Environmental oestrogens - found in some foods, sprays and dioxins - can affect male foetuses leading to reduced sperm production in later life.
Average sperm counts for sperm donors in the Auckland and Waikato region (million sperm per ml of semen):
* 1984 to 1990: 100-110 million/ml
* 1990 to 1998: 80 million/ml
* 1998 to 2003: 60 million/ml
- HERALD ON SUNDAY
