Go to www.livestrong.com and then search "hiking and swelling hands" it explains it pretty well and even mentions pregnancy as being a similar toward the end.
Swelling...I can't tell just by looking at mine that they are swollen, but its the same kind of feeling when I go hiking. Which is pretty common with hikers to also get swelling in their hands and arms. Doesnt hurt but feels tight. I'm 36 weeks and definitely have that issue in my hands too. Kind of hard to grab things as easily?