Yep, logically you would think that gaining a lot of pregnancy weight would have something to do with SPD but I don't actually think that's true. I only put on 6kg.

Bjrose, there's some info out there from one of the pelvic instability support groups that advises what to do when it comes to the birth. I just had a quick look and couldn't find it again but from memory it says to get someone to measure with a bit of string how far you can comfortably open your legs, then take that string with you and don't allow the midwives to get you to widen further than that. Also, it's important to try to avoid an epidural as although that will mean that you can get into the 'on back, legs separated' position without pain, you're likely to pay for it down the track.

If only I'd known then what I know now!