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.