Pillow Arms

It amazes me how the body reacts to pregnancy. Is there really a reason to gain weight in the upper arms during pregnancy? Does it accomplish anything? I ask myself this all the time as I am frequently annoyed by the extra fluff. But then Annah falls asleep at night and uses my arm as a pillow. While I don't care for my arms too much it sure gives me a reason to enjoy the extra fluff there for the moment.