China's relaxation of its one-child birth control policy after three decades has not resulted in a baby boom as officials once feared.
In the first year of the policy relaxation, less than one-tenth of the couples eligible to have a second child have wanted to do so, or have filed their applications, according to the nation's top family planning authority.
Urbanisation is said to be one of the main factors contributing to the slow growth in the birth rate.
Mao Qun'an, spokesman for the National Health and Family Planning Commission, told a media conference on Monday that fewer than 1 million couples have applied to have a second child since such applications became possible in March 2014.
At the end of 2013, the central government decided to relax the birth rules by allowing couples to have a second child if one of the parents is an only child. Previously, they were both required to be only children to have a second child.
At least 11 million couples have become eligible following the change, which is aimed at addressing tough demographic challenges such as a rapidly aging society and a shortage of labour.
Mao said: "The number of applications is still in line with the estimate of less than 2 million annually. The commission will further improve the population monitoring mechanism to guide future fine-tuning of related policies."
Even a slight change to the birth rule would have a huge socioeconomic impact, Mao said, adding, "Factors like the supply of health and education resources for the additional babies must be considered and assessed beforehand.
"We never want a pileup of new births that society cannot handle," he stressed.
Previously, experts estimated that the policy relaxation was expected to result in a baby boom of about 13 million in five or six years.
Zhai Zhenwu, director of the School of Sociology and Population Studies at Renmin University of China, said, "A mini baby boom lasting five or six years with an extra 2 million babies each year on average was expected."
Lu Jiehua, a professor of demography at Peking University, said the figure just released is far lower than expected.
In 2012, a regional survey by the commission found that nearly 60 per cent of the newly eligible couples wanted to have a second baby if allowed to do so.
Lu said that a rapid urbanisation rate has, to a great extent, changed public opinion about having babies, particularly in urban areas. "The policy change is most relevant to urban residents," he added.
Mao agreed and expects more couples to apply this year, but he declined to give a timetable for introduction of a comprehensive two-child policy.
Lu said this is expected to come in five years, adding that long-standing population issues have to be solved.
China's working population began to drop in 2012 by 3.45 million each year and is likely to fall by 8 million annually after 2023, he said.
The number of people aged at least 60 will reach 400 million and account for one-quarter of the population in the early 2030s, up from one-seventh at present, according to the commission.