A large portion of the population see a big distinction between terminating a fetus and terminating a baby. So yes, divulging knowledge of gender before birth will almost certainly result in more terminations.You can't stop a motivated baby killer by denying access to information.
How many more is what is up for debate. If the abuse of female babies remains institutionalized (poorer lifestyle, education or even banishment ) then Monique's solution has not solved the problem. In this sense Upisoft is correct, the key is to address the underlying gender bias.