It's hard to just ignore, when you know you'll be affected. I too, cannot just simply ignore such people and comments.
Maybe the next time they ask to meet, you can try replying them jokingly "Huh don't want la, later you all make comments about my bump and my physical changes again, very sian/sad leh", and add a smiley face like this 😅.
They'll get the point. They'll probably say oh sorry they didn't realize their remarks offended you. And you can smile back/reply with smiley emoji again and tell them yea you were a little upset but it's okay, you know they meant no harm. Then proceed to discuss your meeting plans. The next time you guys meet up, they'll be more aware and less insensitive. (Hopefully)