I've never fasted for mine.
Actually I was told all three times to not fast.
My midwife says eat smart. Like: don't eat right before you go in, don't eat a ton of sugar that day, don't drink sodas or juices..... things like that.
I'm mobile.... sorry for the typos!
Amanda- wife to DH. Mama to W (2010), L (2011), H (2013) & expecting #4 Jan 2016