Rosemary Kennedy wasn’t like the rest of her family. She had the same dark hair and bright eyes, but she suffered from a mental deficiency.
When Rose Kennedy, Rosemary’s mother, was about to give birth to her, the obstetrician happened to be running late. Since the nurse was reluctant to deliver the baby without him, she simply reached up and held Rosemary in place in the birth canal. This cut off the crucial oxygen supply to the baby and ultimately led to a mental deficiency.