Old Wives' Tale or some truth behind it

So a coworker of mine almost started lecturing me about getting something out of a wall cabinet.  He said that I shouldn't lift my hands over my head because it will cause the umbilical cord to get wrapped around the baby's neck.  
I've never heard of this before getting pregnant, but this is the second time I've heard of it and both from African-American friends. 
Any truth behind this or a Mumbo-jumbo myth?  Anyone else heard of crazy but similar warnings?