My mother told me about her Aunt Sophie, her father's sister, who was very obese. Mom said she weighed at least 400 lbs if she weighed an ounce, but she was only about 5.5 feet. Her husband, Chester, was always in and out of the pokey for petty theft and other minor offenses.
About 6 months after Uncle Chess went back jail, she began having serious stomach cramps, ran to the bathroom thinking she was going to have an episode out one end or the other --- sure did, but not what she expected. She ended up delivering a 5 lb son she had no idea she was carrying. With her extreme weight, she had no clue he was in there. She was told she could never have children so probably put any movement she felt down to gas pains.
Uncle Chess accused her of cheating on him, but the baby looked just like 'im, and was so tiny that they could easily trace back to when he was still out.
About 6 years later, it happened again, but this time Uncle Chess was out the whole time. She had no idea she was pregnant, but the 'stomach cramps' gave it away and she knew to get to a hospital instead of going to the bathroom. This time it was a little girl, not much bigger than her older brother at birth.
And as to how it is that maybe they didn't feel the baby moving, my second pregnancy was odd. My daughter didn't move much at all. She didn't move around, didn't kick the daylights out of me, and the doctors were really worried about her, and thought maybe she was not developing properly or maybe died, but tests always seemed to show that she was alive and all her pieces-parts were in good order. She laid across me, butt up under my navel (I used to rub that lump and after birth, it was easy to quiet her down - just rub her bum and she went right to sleep) She didn't move from her lateral position to head-down until a few
days before birth! Now, I certainly felt that - it HURT
- she was 21 inches long by then and it felt like the movie Alien, like she was trying to work her way out of my stomach! If the baby was tiny, though, and I was as overweight as my Great-Aunt Sophie, I can see where I
might not recognize pregnancy, especially the first time 'round. With that baby, my labor was only 3 hours long, most of it happening at night. (I always liked that child!) I woke up, felt horrid, but having had labor once before knew to go to the hospital in time to deliver.
We figured out pretty fast, though, why my girl seldom moved in utero - she was saving all her energy up because once she was born she never STOPPED moving!