BEIJING // Ding Yanhong's two-year-old son is a handful, never keeping still and determined to run away the moment his mother's eyes are turned.
Perhaps it is no surprise then that Mrs Ding and her husband have decided Chuanyu will be their one and only child. However, it is not just Chuanyu's incessant scampering and demands that led the Beijing couple to this conclusion.
Financial factors, including living costs and the "social maintenance fee" imposed by the authorities if she decides to have a second child, also played a part.
"Because of the everyday payments and the government payment, we prefer not to have two children," said Mrs Ding, noting that the fee amounts to more than 10,000 yuan (Dh5,564).
"If there was no policy, I would be very happy to have a second child. The grandparents also would be happy. Sometimes only children feel lonely."
Despite this, Mrs Ding supports the policy. "China has a big problem with the population. It is very large," she said.
It is three decades since China introduced its one-child policy, and the authorities claim it has prevented 400 million births in a country which remains the world's most populous with 1.33 billion people, according to World Bank figures.
The policy is not applied universally. Many are allowed more than one child, including members of officially recognised ethnic minorities, and couples from the majority Han group, if husband and wife are only children.
In rural areas, where children have to help with farmwork, often two children are permitted. Yet the policy is still thought to apply to about 60 per cent of couples.
The rules should remain for at least the next 10 to 20 years, believes Chen Xin, a professor at the Chinese Academy of Social Sciences, because the "Chinese population is still very huge". The public supports the policy, he said.
"To keep the Chinese population at the present stage is very crucial for future development," he said.
Yet pressure groups oppose the policy and what they describe as abuses in enforcement.
A report released last month by Chinese Human Rights Defenders (CHRD), "I Don't Have a Choice over My Own Body", alleges "coercion and violence" to prevent couples having more children. The group says these will remain a problem while the policy persists.
CHRD says the fitting of contraceptive devices, late-term abortions and hysterectomies are forced on women, with officials given pay rises, bonuses or promotions for doing well in meeting targets for these.
Last week, the Global Times newspaper reported women with two children in one area of Hunan province in south-east China had said they had been forced into having hysterectomies, despite government rules stating couples can choose which contraception method they use.
Wang Songlian, CHRD's research co-ordinator, said it was common for local officials to carry out "campaigns against noncompliance".
Enforcement was uneven, depending upon whether officials had met quotas, she said, and officials sometimes levied excessive fines on couples with too many children.
"In rural areas, family planning has become a source of income for the local government officials. They have used this opportunity to make money," she said by telephone.
"The officials feel they can be above the law."
Men and women who have violated the policy have been detained, beaten, fined and sacked from their jobs, and their children denied the registration permits required to access government services such as education, the group alleges.
The policy has also been blamed for an imbalance in gender ratios, because of female infanticide and the selective abortion of female foetuses, with 119 boys born for every 100 girls in 2009, and for speeding up the ageing of the Chinese society, as the ratio of young to old declines.
Li Bin, the minister of the national population and family planning commission, said in an interview last month that China would retain its "family planning policy" for "a long time".
She said it had "helped China achieve rapid economic growth and the gradual establishment of a social welfare system", although some have said birth rates would have declined anyway as living standards increased.
CHRD expects more exceptions to the one-child rule to be introduced, but said this was not enough.
"Even if there's an increase in the amount to two children, it's still a violation of reproductive rights," Ms Wang said.
Yet many agree with the policy. Li Yanchen, 26, a travel agent and only child, said "there are too many people in China".
"It's good for me to be an only child," he said.
Sitting next to him in their office in eastern Beijing, Song Dongdong, 27, also an only child, admitted he would feel lonely during Chinese festivals or holidays.
"You need a relationship with a brother or sister," he said. "If the family has more than one child, they will feel happy and enjoy life."