Cui Wenlan was devastated when she heard the news last month that China was scrapping its one-child policy. She is among more than a million grieving Chinese parents who have lost the only child the government allowed them to have.

Cui's son was 30 when he died after an illness and she had been forced to abort her second baby in 1985. Now she and her husband are adrift in a country where parents traditionally rely on their children to look after them in old age.

"If, back then, we had been allowed to give birth again, I wouldn't be in so much trouble and wouldn't be so lonely," said Cui, 53, from the northern city of Zhangjiakou.

Cui's story underscores the punitive nature of China's family planning policy, beyond the more well-known stories of forced abortions and sterilisations, and highlights the plight of an estimated million "shidu" families, or those who have lost their only child.

China, the world's most populous country with nearly 1.4 billion people, says the one-child policy has averted 400 million births since 1980, saving scarce food resources and helping to pull families out of poverty.

Cui's husband, Gao Zhao, said the government of Zhangjiakou gives the couple 680 yuan (70 pounds) a month in compensation, an amount that falls far short of what is needed in a country where there is little in the way of welfare or health benefits.

"We are rural people and don't have much education," Gao said. "The state told us what to do and we followed."

Cui said she could not get surgery after being injured in a car accident because she did not have a child to sign the agreement for surgery.

Fan Guohui, 56, has petitioned the government to support "shidu" parents financially and emotionally. His son died from a car accident in 2012. Fan's wife, Zheng Qing, said the couple was "emotionally ruined".

"One-child families are walking a tightrope," Fan said. "Once you lose your child, you lose all hope."