I posted about itchiness and pregnancy on my blog's Friday post. You should definitely see your doctor about this to see if it's Intrahepatic Cholestasis of Pregnancy (ICP). You mentioned your liver enzymes are fine, so you may be somewhat aware of this condition. However, the only test to see if you have this is the bile acid blood test. You can have ICP and your liver tests can still come back absolutely fine. I recommend visiting www.itchymoms.com . That website has great info on ICP. Then you should go to the doctor pronto to get your bile acids tested. For more immediate relief (kinda, sort of), sarna lotion helps for a few minutes (if ICP, it may help longer if it's something else).
I had ICP with my pregnancy, and it does tend to come back with each pregnancy--oftentimes worse and it does go away immediately after delivery. You really sound like you may be a potential candidate for it. Read the itchy moms site, educate yourself on it, then head off to the doctor!
C.
www.littlebitquirky.blogspot.com