The Pregnancy Institute has some fascinating information about umbilical cords and the problems that sometimes happen. This is particularly interesting to me because when my niece was born via emergency c-section, the doctor announced that her cord was wrapped around her body 3 times. (She had not been descending and her heartrate had been decelerating during contractions.) I also have a cousin who's umbilical cord wrapped tightly around his arm and caused that arm and hand to be smaller than the other.