mine started in month 3 prenatally and finally cleared up in month 9 postpartum.
i had the problem that my doc didn't believe that i was in pain. i should have included the descriptor of "debilitating".
some useful material that i found:
acupuncture apparently works (
http://www.swedish.org/111013.cfm)
there are European guidelines (they're more enlightened about this sort of thing...
http://www.backpaineurope.org/web/fi...Guidelines.pdf)
and there's an organization in the UK that puts out this document for caregivers (and patients):
http://www.padge.eclipse.co.uk/spd.doc -- i highly recommend reading this one before you give birth!
physical therapy helped postpartum but i'm sure it would help prenatally as well. my sister said that a trip to the chiropractor helped her. either way, make sure you see someone who specializes in prenatal work or in pelvic issues.
postpartum, you will want to focus on spinal alignment really carefully. "if it hurts, don't do it" really does apply. once i started focusing on spinal alignment, i noticed that i regained much of my pelvic stability. when i went to my last PT appointment (with a pelvic specialist), we were working on stability from my knees down - my hips and legs are hypermobile which probably contributes to SPD. magically, i noticed over the past few weeks, i'm moving around more easily. not quite ready to take up the exercises in exerciseafterpregnancy.com - afraid that i'll revert back to the state of constant pain....