Although Wang Xia has a successful career as a university lecturer in Henan province, life isn't perfect. She cannot bear a child.

"I really want to have a child, and I've tried several hospitals for treatment but failed," Wang said, adding that she ended up divorced from her husband because they could not have a child.

Wang became pregnant after she got married but went for an induced abortion because she wanted to pursue her career.

A surgical infection caused her reproductive difficulties.

According to the China Population Association, more than 40 million Chinese people are diagnosed with infertility, 12.5 percent of those of childbearing age. The rate was only 3 percent 20 years ago.

The first test tube baby on the Chinese mainland was born in 1988 at the Center of Reproductive Medicine of the Third School of Clinical Medicine of Peking University, where every day about 1,500 patients wait to see reproductive experts.

Qiao Jie, director of the center, said many professional women postpone marriage and having a child.

"Their reproductive ability deteriorates when they eventually want a child," Qiao added.

According to Guo Yihong, vice-director with the Center of Reproductive Medicine of the No 1 Hospital Affiliated with Zhengzhou University in Henan, the number of infertile people is increasing, with more than 150,000 patients accepting treatment from the center in 2011.

Zhang Cuilian, an expert in reproductive medicine at Henan Province People's Hospital, said that tubal obstruction and overly thin lining in the uterus caused by induced abortions is the prime cause of female infertility, Zhang said.

Zhang knows of one woman who had 10 abortions during her 20s, thinking that she and her partner would have a child at a later age. However, she could not bear a child when she was 30.

Experts also said living conditions may cause infertility, such as street pollution, formaldehyde in new furniture and radiation from daily electronic devices.

Staying up late and pressure can also lead to infertility, said Peng Hongmei, associate chief physician of gynecology and obstetrics of the Chinese People's Liberation Army Hospital.

Peng has witnessed a surge in patients seeking treatment during the last two years.

"The prime time for women to bear children is in their 20s to at most 35," Peng suggested. "Giving birth to children at a relatively young age will not only increase pregnancy quality but also repress some gynecological diseases."