I have doubts about whether this is truly your wife. These doubts are founded on past incidents in which a person would post a few random photos of a woman they were unrelated to, and then simply said "My wife!"
To my knowledge there's been one exception but with marked differences. One, he didn't show her face. Two, his wife was also a pregnancy fetishist and they almost did a sort of q&a IIRC. I believe it ended with something like "This has to be our last kid. You guys don't understand how much work it is to actually raise kids."
If this is honestly your wife, then I question whether she knows you're sharing these photos. It would make more sense if she took pregnant photos of her belly with you hugging her or some such thing if you were really her spouse/significant other.