Zhao Ping, former deputy chief of the consumption economy research department at the Chinese Academy of International Trade and Economic Cooperation, a think tank under the Ministry of Commerce, said that will be a major consideration in the short term

"(Couples) aged between 36 and 45 might be less willing to have a second child," Zhao said. "Even if they do, they will have about 15 years only before they retire."

There are also other concerns. Wang Lei, who has a five-year-old daughter in Beijing, gave birth to a boy last week.

But her delight was tinged with anxiety about the size of the apartment she owns with her husband. "I thought if the baby was a girl, they could share the same room," Wang, 36, who works at a foreign medical equipment company, said.

"Now we have to find a three-bedroom apartment, which is 2 million yuan more than the one we live in, and it might not even be in the school district," she added.