I don’t think this is an appropriate time to make political statements. It is a happy time, where family and friends gather to “shower” mom with gifts for the new baby. People who are pro choice aren’t baby haters, especially if they are going to a baby shower. Now, if someone stands up and yells, “you should have aborted that thing!” It would be appropriate to punch said person in the nose and throw them out. Doubt that will happen.
I’ve seen nail polish given out pink/blue I have also seen where people just tied pink/blue ribbon around different types of polish because well, pink is only for summer and blue nails look like you have lost circulation.
I have also seen cheap baby bottles filled with candy. Popcorn balls with “about to pop” written on it. Loofas with a thing saying “from our shower to yours.”
If it is themed, you could give a favor that goes with the theme.