Zhao Lin (pseudonym) felt awkward sitting in the marriage and adoption registration office in the Jing'an district of Shanghai. Zhao had come to inquire about child adoption.

"Have you found yourself a relinquished child?" A young officer asked Zhao after handing her a pamphlet highlighting the key points of China's adoption law. "No," she replied, surprised by the question.

The 32-year-old was at the office with hopes of being registered as a prospective adoptive parent and getting in line to adopt a child from the city's orphanages.

But she soon discovered it would be a challenging task to find a healthy child.

It now takes nine to 10 years on average to adopt a healthy child from Shanghai's orphanages, according to Chen Zhanbiao, director of the Marriage and Adoption Registration Division of the Shanghai Civil Affairs Bureau.

"Why so long? The major problem is that the majority of the orphans here have serious disabilities," Chen said, adding that domestic families don't want children with any kind of disability. "When domestic families adopt, it's mostly functional. They'd like to adopt a healthy girl so that when they get old someone can take care of them. But some foreign families adopt simply out of a kind heart. They accept children with certain disabilities."

"The percentage of severely disabled orphans is usually above 90 percent," Chen said. "But the city has more than 1,000 families waiting to adopt a healthy child. Over the past two years, of all the adoption cases I've handled, only two children were totally healthy."

Kay Johnson, a professor of Asian studies and politics and director of the Hampshire College China Exchange Program, started to research adoption in China in 1991 when she adopted her daughter from an orphanage in Wuhan, Hubei Province. She said that it's almost impossible for a Chinese family to adopt a healthy baby from orphanages.

"I know in one medium-sized official orphanage in Anhui Province, for example, they may have two or three healthy children a year. And I guess people who get one of these two or three children probably have guanxi (connections) and may offer a large donation."

Zhang Wen, executive director of the Children's Hope Foundation, and also an adoptive mother, agrees with the professor's point. "If you don't know anyone with the civil affairs department or from the orphanages, basically you can never adopt a healthy child from there," Zhang told the Global Times.

The China Civil Affairs Statistical Yearbook 2013 indicated that the country's social welfare institutions held as many as 104,000 children in 2012. A total of 27,278 got adopted that year. There is no official figure indicating how many of these adopted children were healthy.

For families like Zhao and her husband who are facing fertility issues, adoption is now their only hope to have a healthy child.

However, due to the shortage of healthy adoptable kids, many people have turned to an underground market to find children from dealers.

While Zhao knew adopting a child would be a difficult endeavor, it was only recently she discovered it could be illegal.

Zhao had heard the tale of 60-year-old Shen, a Shanghai native, who adopted a grandson from a single mother in the city's Chongming county last year because her daughter was infertile. She was among 19 "illegal adopters" arrested by the Shanghai police in a crackdown in February.

Given this revelation, Zhao now has doubts about whether she will ever be a parent.

Despite being legally dubious, purchasing children has long been a popular option in China. Online platforms have helped connect families wanting to adopt or give away children, and have provided the gamut of services required to get each new baby a hukou (household registration).

In February, the Ministry of Public Security netted 1,094 suspects working for four such online platforms.