From conception onwards, having twins seems to raise the bar. Through pregnancy and birth, mothers having twins are viewed as twice as delicate, with their precious double burden, placing a pressure on babies and parents that impacts on the birth as well as the early days and weeks of the babies' lives.
It's a little like being asked what it's like having a pair of lungs. I don't know - Good? Useful? Essential? Being a twin makes up my DNA: my twin-ness sits snugly inside each and every cell that makes up my body. It's why we have the same colour eyes; the same colour hair and tiny wrists. It's why I am me and she is, well, she.