Is there an economic rationale for wanting to know the gender of a child before it is born?
One typical story people tell is that in some countries there are strict population control policies and if families have a large economic incentive to have either a son or a daughter, they might neglect their pregnancy or terminate it if the child is not the gender they want it to be. In some societies the economic incentives to have sons or daughters are very different: typically sons are expected to bring in a working wife into the family, with a dowry, but daughters are expected to leave to the husband's family and take a dowry with them.