The latest advances in plum belly syndrome are abdominal surgery to correct the absence of muscles or the operation of the fetus in the mother's womb before birth.
I was born without any abdominal muscles and a sunken in chest wall. At age 3 at Texas Childrens Hospital, Dr Abel took some oblique muscles and pulled them around to my front all horizontally. He took sutures and did a boyscout basket weave of sorts...