Well here I go.
Reason 1: If a young queen can reproduce like this, why the hell would it ever need to bother with the whole egg, facehugger thing anyway. Completely f**ks with everything we have learned about the alien life cycle.
Reason 2: The whole idea that it impregnates pregnant women is f**king mind numbingly idiotic? Why just pregnant women? Why cant it do it to any human? What happens if there are no pregnant women just conveniently in the vicinity? But wait there is, in a maternity ward, and oh look the Predalien has stumbled across this maternity ward. Brilliant.
Reason 3: Its a pathetic attempt to include some shocking gore, but it has the opposite effect. Theyve thrown it in there for the sake of it, but havnt really thought it through and to be honest it doesnt really make any sense. But hey its gory so just leave it in. Pillocks.