The relaxation of the family planning policy might be good news for parents who yearn for a bigger family, but it adds pressure on some women who are reluctant to suffer the pain of giving birth again.

The traditional preference for boys still weighs heavily on them. Wu Dan from Jiangsu said she has been pressured by her family to have a second child because her first child is a girl.

Wu said she really doesn't want to go through the pain of labor, and thinking of the cost of raising two children is a headache.

"If I decide to have a second child, it is because my parents and parents-in-law pushed me," she said.

Dr Anna Smajdor, a reproduction and childbirth ethics expert at the University of East Anglia in the United Kingdom, said: "In many cases, it is not that women are not allowed to have more children, but that they do not want to.

"Many countries are seeing similar phenomena, because if women have choice and economic freedom, they do not have as many babies, and they have them later in life thus further entrenching the aging population."