A woman carries her unborn child on the left side of her body, according to Childbirth Connection. As the uterus expands, it pushes against the liver, transverse colon, stomach, spleen, small intestines and diaphragm. The pressure on these displaced organs accounts for some of the discomfort during pregnancy.
By the time the baby is ready for birth, the position of the fetus should be head down with its face turned slightly to the side so that the smallest part of the baby's head can lead the way through the birth canal. This is the most common and preferred position, according to a slide show from the Mayo Clinic.