China's family planning policy received cautious praise at an international conference for its positive effects on the country, and even the world's environment.

"China's constant efforts to promote reproductive health have paid off," Gill Greer, director general of the International Planned Parenthood Federation, told the fifth Asian Pacific Conference on Reproductive and Sexual Health and Rights which closed yesterday.

Since the introduction of the family planning policy three decades ago restricting most couples to one child, more than 400 million births in China have been prevented.

While this has led to a more rapidly aging population and an abnormally high ratio of male births, it has also, however, led to significant improvements in China's life expectancy, education and per capita GDP.

"The ethical obligation of our generation to our children and grandchildren must include slowing the rapid population growth by meeting the unmet needs for family planning," Malcolm Potts, director of the Public Health School of the University of California, Berkeley, told the conference, which closed in Beijing yesterday.

In recent years, China has replaced its focus on controlling its population with a comprehensive approach that includes the size of the population, along with its quality, structure and distribution, in one policy.

"China's family planning program has made significant contributions to the stabilization of the world population, environment protection and energy savings," said Zhao Baige, deputy director of the National Population and Family Planning Commission.

But Greer insisted that once people are given quality education, the size of family should be decided within the family itself.

"What really matters is not how many we are on the planet, but what we do - like we can choose not to drive a car," Greer said.

"Every country makes its own policy, which, however, should be adjusted according to new situations," she said.

To fine-tune its policy, the country now allows urban couples in large cities who are both only children to have two children.

However, a recent survey showed that 47 percent of urban Chinese still favor having just one child, mainly due to the high cost of raising a child.

Nearly 42 percent wanted two.

"Choices made by the people and their rights to reproductive health should be fully respected," said Greer.

China is constantly enhancing sexual and reproductive health services for its huge migrant population, she added.

"The maternity health situation in China is among the best in the region and the government also provides a great variety of contraceptives for the public," she said.

"Other countries can learn about these from China," Greer said.