China's 'one-child' policy

Planned birth policy, as it is known in China, first implemented in 1979

Government permission required for having a child

Strongly enforced in urban areas but varies for different locations and ethnic groups

Those in rural areas usually allowed second child if first is a girl or disabled

Ethnic minorities usually allowed to have more children

Penalties for having more than one child usually economic – fines, denial of work bonuses, having to pay for child to go to school and whole family's healthcare,

But officials also reportedly detain family members, destroy houses, sterilise women and conduct forced abortions

Government blames overzealous officials for any inhumane or uncivilised enforcement of the policy

In some cities, couples who are both only children themselves may have two children

China's fertility rate estimated to be between 1.6 and 2 births per woman

Government says 1.3 billion population is 300 million smaller than it would have been without policy

The imbalance has grown since China introduced a one-child policy more than 25 years ago to curb population growth in the world's most populous nation - now with about 1.3 billion citizens.
 
The restriction has bolstered a traditional preference for boys, and has created "a hidden danger" for society that will "affect social stability", the document said.
 
But the authorities reaffirmed their commitment to the one-child policy, saying the nation continued to face big challenges from its growing population.
 
"Maintaining a low birth rate is the priority of family planning during the next phase," Xinhua quoted the document as saying.
 
The report follows one issued by the State Population and Family Planning Commission, warning that by 2020 China will have 30 million more men of marriageable age than women.
 
To fight the imbalances, the authorities said they would also step up supervision over hospitals that use ultrasound equipment or abortion pills, Xinhua reported.
 
Last year it scrapped plans to make sex-selective abortion - which is already banned - a crime. Experts have said such a step would more effectively deter parents from aborting baby girls.