Beijing's municipal government is relaxing its one-child policy, allowing couples to have a second child if either the mother or father is an only child. The move was announced after the city's Population and Family Planning conference on Friday.

In the past both parents had to be single children to be entitled to have a second child. To qualify for a second child couples are also required to ensure there is a four year gap between their first and second child if the mother is under 28 years old. The ammendment comes after a major Communist Party meeting in November that set new standards allowing local governments to change their family planning regulations.

China's Zhejiang province was the first in the country to relax family planning rules in January. By the end of 2013, Beijing's population had soared to more than 21 million, due mainly to an influx of migrants. The city's population control target for last year was 18 million.

Every year in Beijing more than 270-thousand babies are born, but the city's birth rate, which is under 10 per 1,000 people has been in decline since 2000. Analysts say Beijing's relaxing of its one-child policy will mean an additional 54-thousand babies will be born in the city each year.