Falling sperm counts in China may hurt effort to boost birth rate, statistics suggest
- Trends are in line with those in the developed world
- Critics discount research that suggests male infertility is increasing
Is China in the midst of a sperm crisis? New statistics strengthen a growing belief that Chinese men are joining the developed world in producing less sperm in their semen, a trend that raises questions about their fertility in a country that is trying to boost its birth rate.
At Shanghai-based Fudan University’s sperm bank, which opened in June, just 10 per cent of semen collected from over 100 donors aged under 35 met the bank’s quality standards, local media reported.
The quality drop was in evident at the 15-year-old Shanghai Human Sperm Bank at Renji Hospital, where 25 per cent of the semen taken from donors last year was acceptable, down from more than 40 per cent in 2013.
And the sperm bank at Peking University Third Hospital in Beijing had fewer than 20 per cent of samples collected from September 2015 to May 2016 make the grade.
What’s happening in China seems to be in line with what researchers have found in the developed world. Last year, a study suggesting that sperm counts of men in Western countries had dropped by 50 per cent within nearly 40 years provoked heated global discussion.
A meta-analysis of more than 180 research papers published from 1973 to 2011 indicated a 52 per cent decrease in sperm concentration and a 59 per cent decline in total sperm count among men in North America, Europe, New Zealand and Australia.
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The statistics come as China faces huge challenges with its new births in decline and a quarter of the population expected to be aged over 60 by 2030. Its rapidly ageing population pushed Beijing to end the notorious one-child policy – introduced in 1979 to control population growth – in 2016, and couples can now have two children.
But despite the new policy, just 17.6 million babies were born in mainland China last year, compared to the 241 million people aged over 60, Xinhua reported in June, citing National Health Commission figures.
“Falling sperm count is an indisputable fact globally,” said Qi Guangchong, an andrologist from Shanghai’s Yueyang Hospital of Integrated Traditional Chinese and Western Medicine.
Based on an international examination of the semen of men whose partners had conceived within 12 months of first trying, the World Health Organisation has suggested that “normal” human semen today contains at least 15 million sperm per millilitre, and boasts at least a 40 per cent rate of motility (the ability of organisms and fluid to move or get around).
Nearly 40 years ago, when the WHO’s first edition of its laboratory manual for the examination and processing of human semen was published, the lower limit of output of sperm per millilitre in its member states was 60 million and the motility rate 70 per cent.
The publication has been updated four times since then, and each time the standards by which WHO judges the acceptability of sperm have been lowered.
By contrast, sperm banks in China today follow health ministry guidelines that are similar to those set by the WHO four decades ago, setting the bar for sperm count at 60 million sperm per millilitre and for motility at 60 per cent.
Although declining sperm output was a real issue in China, the statistical drop in sperm quality partly reflected China’s stricter quality standards compared with much of the world, Qi said.
“Because the cost of getting a sperm donation [in China] is quite high, [owing to] the physical and psychological check-ups, the compensation for donors, et cetera, the sperm banks need to make the most out of each sample,” Qi said. “They need much better quality semen than what is normally required to get a woman pregnant.”
Then what might have damaged men’s swimmers? Studies by researchers across the world have identified more than a dozen possible culprits.
Professor Wang Guomin, an expert on the male reproductive system at Zhongshan Hospital in Shanghai, said chemicals, ionising radiation, heat, smoking and drinking are among the usual suspects.
“Amid rapid industrialisation, we are exposed to a great amount of chemicals in our daily life via the consumption of medicine, food, cosmetics and so on,” he said. These chemicals can disrupt the endocrine system – pertaining to the glands which secrete hormones or other products directly into the blood – or create a “genetic shift”.
Other possible sperm-killing pollutants come from the burning of waste, the widespread use of pesticide and the emission of industrial production – factors that have been linked to the onset of cancer, he said.
Infertility, a hardship experienced by both men and women, is increasingly arousing concern in China.
The official infertility rate for married couples in the country ranges from 10 per cent to 15 per cent now, compared with three per cent more than 20 years ago, according to studies by the Chinese Population Association.
By contrast, the Centres for Disease Control and Prevention in the United States has suggested infertility rates in the country may have declined between 1982 and 2010. The national public health institute found infertility affected 2.4 million women in 1982, compared with 1.53 million in 2010.
But Wang Wenjun, the deputy head of the reproductive centre of Sun Yat-sen Memorial Hospital in Guangzhou, said those figures did not accurately measure infertility growth in China.
“Two decades ago, we had far fewer medical resources and people didn’t go fix their infertility problems,” she said. “But in general we are seeing a growing infertility.”
Still, some experts criticise the validity of existing studies and falling sperm counts that suggest male infertility is increasing.
Wang Guomin, the Zhongshan Hospital male reproductive expert, said the widely quoted meta-analysis published a year ago in the journal Human Reproduction Update was based on old studies from different regions.
The research likely contained either unmeasured variables or confounding factors that could have influenced the results, he said.
“To look at the issue more accurately, we should do new experiments specifically designed to test men’s semen for, say, 20 years, preferably on both sperm donors and men who have conceived within six months of trying,” he said.
Wang Wenjun, the Guangzhou reproductive expert, said even though the results may truly represent the health status of the general public, sperm counts in those studies were still well within the normal range, or sufficiently adequate to get a woman pregnant.
“Therefore, a decrease in sperm counts isn’t equal to a decline in male fertility,” she said.