This is DC3, and I've had it with every pregnancy, really quite badly and from about 16-20 weeks I can barely walk, sorry, hobble anywhere - no more than a few hundred yards most days and I need a wheelchair for anything more e.g. a big Tesco, large malls etc.
I'm somebody who thinks nothing of a 10 mile walk on a day at the weekend when not pregnant, and loved cycling and more recently became a runner.
With DC1, I had a precipitous early labour at 36w6d and the SPD did not really affect things at all thankfully for the birth. I made sure my legs weren't too separated and yelled at the midwife when she got the stirrups out. I felt a lot better right away and within a few weeks I was only in discomfort if I did scissor kick style movements, rather than with every waking (and sleeping!) second.
With DC2 it was even worse as I was also officially on bedrest so sitting on my backside for so long meant things seized up even more. I had an EMCS for unrelated reasons, but was naughtily out shopping 5 days later feeling fantastic and the SPD was gone long before the EMCS issues were.
I was so hacked off with SPD, I decided to run the London Marathon the following year (with no previous running experience) to stick my finger up at it. The marathon was exhausting, but not because of SPD!! I can sometimes feel discomfort at certain times of the month but it's not life changing - it can be ignored. There were far worse pains associated with long distance running!
Now nearly 35 weeks with DC3, nearly crippled myself in agony walking between a few shops just now and in intense pain, as always. Seeing an osteopath weekly which helps compared to previous pregnancies.
But because I know it will go again, I can tolerate it mentally. I'm already planning on long distance races to run this autumn, and buying some rollerskates to keep fit and to stick my fingers up at it again :)