C&C per req:
1. Good expressions, BUT why is he looking image left and she sort of looking at him? I would crop this one even more tightly to get rid of all the empty space.
2. Nicer crop/composition, but again, he's not "in it"; he's staring off in the distance, and she's sort of looking at you. One of your most important jobs as a photographer is to keep an eye on things like this and sort them out. He should either be looking at you or (since it's materinity) at her.
3. Way too tight for my tastes, and really, I don't get much of a hint that she's pregnant. As with the others, he's looking at something else.
Overall, they're not a bad set. The exposures have the skin a bit hot, and I think some fill light would have helped.
Just my $00.02 worth - your mileage may vary.
~John