Sperms preserved inside cans of liquid nitrogen at Lu’s hospital. [Photo by Zhang Wei / China Daily]

She is likely to spend more than 70,000 yuan in rents, medical bills and food in the three months. For example, procedures such as egg extractions from a woman's ovary can cost up to 30,000 yuan. The mixing of eggs and sperms in a laboratory thereafter hikes the bill.

But Chinese doctors argue that rates at more than 100,000 yuan for IVF cycles in the United States are still higher than China.

"My parents worry I may not have a baby if I wait longer," says Su.

She is among the younger enrollees for the assisted programs, but after her marriage of four years she is faced with social pressure to have a child. Unlike Jian and Liu, who came unaccompanied by their respective husbands to Changsha, Su's husband is by her side.

Of the 90 million Chinese women able to now have second children if they wanted, half are between the ages of 40 and 49, the central government estimates.

In its latest report, the China Population Association said 12.5 percent of the country's population - within the reproductive age bracket - is likely infertile. The percentage, four times higher than two decades ago, translated to about 40 million individual cases.

The conventional international approach on reproductive populations is to look at people from ages 15 to 50, but doctors in China as in many other parts of the world, say it isn't easy to precisely measure infertility rates as the calculations are complex involving a host of factors from social to environmental.