I am in this situation right now! I'm coming up to 30 weeks pregnant and have a 22 month old DS. And I have just developed SPD

I do lift him a fair bit, my main prob is he's at that age where if he doesn't want to do something he will do the stop drop and roll, and I have to pick him up. Especially if we're at the shops etc. Pretty soon I think I'll start changing him on the floor (he's not TT) although the getting up and down off the floor is just as hard at the moment. And also, DH is working 7 days a week at the moment and sees DS for about 10 mins a day so I can't defer any of the heavy stuff to him.

So yeah, in my case lift him a fair bit. I'm wondering the same thing now - could I even handle a third pregnancy if this happens again...