Chinese government abolished one-child policy and also the following two-child policy. Actually, at the moment they have the opposite problem: the population is aging and the new generations do not even have enough children to guarantee their generational change.
I wonder if the old one child policy had a knock on effect, changing the societal norms and views of having multiple children? A knock on effect that didn't go away after the law was relaxed perhaps.
Are you forgetting the one child policy?
That is a blurb for the article posted by the submitter, the third sentence of which will answer your question.