According to statistics released Sunday by Beijing Municipal Commission of Health and Family Planning, of the 21,249 couples who filled birth applications, 19,363 have been given the permit, Xinhua reported.
Of those granted permits, around 56 percent were women aged between 31-35 years, the commission said.
It also said that there were 537 women aged above 40.
At the end of 2013, China relaxed the decade-old one-child policy which was designed to curb population growth.
A majority of the Chinese provinces have allowed couples to have a second child if either parent is an only child.
The relaxation came as China is coping with a declining labour force and an ageing population.
Demographic experts have said the easing will help promote balanced population growth in the country.
Under the one-child policy, many couples, particularly in China's countryside, committed abortions as they prefer boys to girls.
This led to a wide gender gap of 118 male births versus 100 female births in 2010.