If you raise your arms above your head while pregnant (as when you are hanging up clothes on a clothesline), the baby will get the cord wrapped around its neck.
Actually, the movement of the mother doesn't really affect the umbilical cord - unless she stands on her head. Research have shown that Up to 25 percent of fetuses have the umbilical cord wrapped around the neck, but this is not something that a mother can prevent. The fact that the cord is often around the baby's neck because when a baby is in the proper head down position, that's the most natural place for the cord to settle. The good news is that nearly all of these babies develop normally and are successfully delivered.