The universal second-child policy implemented early last year was a major factor in raising the number of births in China to 17.86 million last year, an increase of 7.9 percent and the highest annual number since since 2000, according to the top health authority.

The number of newborns has increased by 1.31 million compared with 2015.

The portion of the births to couples who already had at least one child rose quickly to at least 45 percent last year, Yang Wenzhuang, a division director of the National Health and Family Planning Commission, said at a news conference on Sunday. The proportion was around 30 percent before 2013.