What determines when a woman will start showing -- weight, height, genetics, water retention, none of the above? My sister is 15 weeks pregnant and is not showing at all. I'm 12 weeks and am really showing. She's much more slender then I am, weighing about 15-20 pounds less (same height though). Just curious on why this is.
All of the things you mention, plus size of the uterus, which number baby it is, how the woman carries the baby, how many babies she has, and wrong dates just to name a few.
If this is not your first baby, what is showing is probably not the baby at 12 weeks, but the mommy. The top of the uterus on most women is just peeking over the pubic bone at 12 weeks, so anything above that is not the baby.
-- Cynthia, CNM