I never heard of it till I came to this forum and I swear it must be catching because I didn't have it with either of my other two pregnancies. Thankfully, while it can be very painful, especially when in bed, getting up and first moving around, it's not crazy bad. My doctor told me to get a support belt, see a chiro, one who specializes in pregnancy, he even gave me a name of someone and make sure to do light exercises, but don't overdo it. If it hurts, stop. I do a lot of stretching and try to get in at least a short walk every day.