This. Personally has caught me a tad bit speechless. What I love most about this, is that you chose to go black and white! Color would not have done it justice. For some reason, it amplifies the love and emotion in this picture. Even though the mother's face is shadowed, her smile is still powerful enough to stand out.
The kiss of the belly, the smile of the woman, her being pregnant all comes together to make a very powerful picture.
Now in terms of what could possibly help this picture to be improved. The only thing I would suggest, is if the left side of the picture was cropped just a tad bit more. And the male's glasses, I think if they were removed, it would allow us to see more emotion in his face, which would help the picture out as a whole.
Regardless of those two minor details. It's an amazing shot. Great work! Keep it up !