When Chen Song married Wang Qian in 2006, his parents thought he had made the perfect choice and bragged about her beauty and obedient nature to friends and family.
Yet, three years later, simply a mention of their daughter-in-law's name was enough to throw them into a fit of frustrated anger. The reason: Wang was unable to get pregnant.
"We love children. We had planned to have one as soon as we got married," said Chen, 35, an associate college professor in Shanghai. "But it didn't happen. My wife's belly remained flat."
After several medical check-ups, Wang, now 31, was diagnosed as infertile, a condition that is becoming increasingly prevalent in men and women across the country.
"My parents became furious whenever they heard about one of my classmates or friends having a child. I was afraid to go home," said Chen, who with Wang, has spent thousands of yuan trying to get help from 10 hospitals.
More than 40 million people suffer infertility problems, accounting for about 12 percent of the population who are of childbearing age, according to data released during the China International Summit Forum on Infertility in Beijing in August.
And in some developed coastal regions, the proportion is even higher.
Figures from Qingdao Maternity and Children's Healthcare Center in Shandong province showed the city's infertility rate has hit 15 percent, while a survey by the Dongguan Family Planning Association in Guangdong province found sterility affected 18.9 percent of the local population.
"It means almost 1 out of 8 couples at childbearing age in China faces the problem," said Yuan Xin, a professor at Nankai University's population and development research institute. "Twenty years ago, the national rate was just 3 percent."
Concern is now growing over how the trend will affect marriages, as well as the impact a lower birth rate will have on China's aging society.
"If we don't take effective measures to cope with increase in sterility and raise the birth rate, society will face severe challenges in the future," warned Yuan.
The reasons behind growing infertility are numerous, say experts, who blamed a combination of unhealthy lifestyles, work stress, the greater use of abortions and worsening environmental pollution.
However, most agreed that the chief culprit is the fact more women are marrying and trying for children after the age of 35.
Although a large number of young people in China see a good career and strong financial foundations as the perfect conditions for having a child, medical professionals argue that the only real indicator is the reproductive system, commonly referred to as the "biological clock".
"Generally, women over 35 are more likely to encounter difficulties in conceiving, as well as more likely to suffer miscarriages or have babies with defects," explained Dong Ziqiang, a professor and expert in fertility at Peking Union Medical College Hospital. "For men, the older they get the more abnormal genes contained in their sperm, which can cause problems."
