I don't think there's any truth to that, personally. I've not looked into it, but if that was the case, you'd have to wonder why so many people chose to terminate girls and keep trying until they have a boy, or why so many baby girls are abandoned in certain countries, because they want a boy instead. If anything I'd say it was the other way around - but I don't think it would really apply in either circumstance. It's all down to genes, DNA and chance!