See how the "Chinese authorities" distort things:
Chinese authorities say an unknown number of children are abducted every year for sale to childless families. Older girls are sometimes sold as brides in rural areas with fewer women.
This article is about babies.
There is a one child policy. This extra kids are not allowed. If they are born they have to be hidden. That could include being sold or given away. At least they are alive not aborted.
If the families kept these children they'd be at risk of having their house buldozed and being thrown in jail for not being able to pay extortion level fines.