The gender of a baby cannot be predicted by the size or shape of the pregnant tummy, but there are many things that a belly of a pregnant woman is about to become pregnant.What is the size and shape of your pregnant tummy? (Source: iStock) Why are there women who are 6 months pregnant but can't see it on their stomachs? Why do other odds seem like they are twins, even triplets, even though they only have one baby? What does it mean to have a high or low belly? All pregnancies are different, and this includes the fact that the shape and size of the abdomen include everything else.