The world’s most populous country, its resources already straining to meet the needs of 1.3 billion people, is expected to undergo a baby boom from next year.

It will be the third surge in births in China since the start of Communist rule in 1949 but will be on a much smaller scale than the unchecked population growth of the late 1950s and mid-1960s. Then, Chairman Mao exhorted Chinese to have as many babies as possible to make their country strong, and assailed birth control as “bloodless genocide”. The result was an explosion that continues to stretch China to its limits.

To control the birth rate, China imposed a strict one-couple, one-child family planning policy in the late 1970s. The rules were relaxed slightly in 1984 when rural couples were allowed to have a second baby if their first was a girl. Children born after the post-1984 peak are now reaching marriageable age. As they set up families of their own, a new wave of population growth will begin.

In a sign of government anxiety, Zhang Weiqing, of the National Population and Family Planning Commision, admitted that the expected mini-boom would put great pressure on the country.

He added that he expected the boom to last for a decade. and said that China faced a stiff challenge in its campaign to keep down the number of births.

The current population of about 1.3 billion would have been nearer 1.7 billion if China had not introduced its tough family planning policies. The average number of children born to each family is 1.8, compared with 5.8 in the early 1970s when Mao Zedong was still encouraging large families.

The force of tradition poses one of the greatest challenges to the one-child policy. Mr Zhang said: “The desire to have boys or more than one child is deep-rooted and still very strong, especially in rural areas. The contradiction between the desire and the current family planning policy remains acute.” Penalties are heavy for those who violate the regulations. Government officials can be dismissed for having a second child. Fines are imposed nationwide on any couple having an extra child. Above-quota children are not entitled to schooling or medical care.

As an extended economic boom brings greater prosperity, however, more and more people are happy to flout the regulations and pay the fines if it means they can have a son. A government survey showed that nearly 80 per cent of couples planning to start a family want to have a boy and a girl. In addition, 41 per cent of couples in urban areas whose first child was a girl said that they wanted to try again in the hope of having a son. By tradition, only a boy can carry on the family line.

Such desires are even more strongly felt in the countryside, where farmers want more children – particularly boys – to work in the fields and take care of parents in old age.

This has resulted in a serious gender imbalance as couples abort female foetuses. China now has a ratio of about 119 baby boys to 100 girls, compared with the international norm of about 107 boys to 100 girls.

One newspaper, the China Youth Daily, called the phenomenon a “social time bomb”. It said: “It will become more difficult for low-income men to find suitable spouses as they get older. A large number of unmarried men could also cause social problems such as violent acts against women.”

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