My mom had to stop work 3 months before she had both of us, she couldn't perform at work and was so uncomfortable she asked the doctor for early inductions with both of us. Me at 38 weeks and my sis at 39. BUT saying that she gained more than 50 lbs with each pregnancy, I've gained 23. I've been working and will continue working till due date and had no problems, no swelling, no sickness, I'm sleeping through the nights (except for a pee break every morning at 5:30), no heartburn, nothing except for GD which has been completely managed by eating high protein & fat/low sugar & carb diet-it's been easy since carby sugary foods give me a horrid rotty mouth feeling. I think each person and pregnancy is different. I've also worked out till well after 7 months, mom has never stepped foot in a gym or done pilates & kick boxing in her life. She kept telling me ' oh you wait till you're in your third tri, then you'll pack the weight on just you see,' as if I HAVE to gain heaps of weight because she did. I think she was secretly hoping I would. I think the amount that I exercise has protected me from SPD, I have extreme flexibility & loose joints due to arthritis (stage 4-I'm due for knee replacements) which puts me at high risk for this (SPD is caused from loose joints. But with the working out & I'm still in the gym, I think it's helped to have strong muscle tone keeping things together. She had arthritis too (only stage 2) and was effected massively with pain in the pelvis & back. But I think everyone eats, moves, and has different bodies just as every pregnancy & birth is different (thinking especially ms and labour length and tearing here).