I'm 30w 2d and I gained 33 pounds by the time I was 27-28 weeks. I have not gained any weight at all since I have been in the third trimester. But then again I have started walking every day and pay close attention to what I eat, how much I eat, and when I eat. Working very hard to be healthy and control my out of control weight gain.
I'm 30 weeks with prepregnancy weight of 123lbs and only gained 12 lbs so far. Baby is measuring perfectly normal. I've given up on meeting my weight gain goal (25lbs) and am prepared for major weight loss postpartum. My GI doctor had similar difficulties in her pregnancy, she lost tons of weight after giving birth but eventually gained them back. It's normal to see weight gain stalk or even drop in 3rd trimester.
I'm 32w1d and I've gained 8.9kg all up
I'm 31.5 weeks now and gained just over 12 kg. .. is hard work creating 4kg babies (this is my third) ;)