I take a fish oil supplement from Pharmax that's great -- and orange flavored so it's not gross nor fishy tasting. It's mercury-free, and while I couldn't tolerate it my first trimester very well (couldn't tolerate much then honestly), I gave up til the nausea passed and now am much better
I take it for the protein and now for baby's brain development but I too have heard about its benefits for skin, so go for it!
I also second the pp with the evening primrose recommendation -- I was taking it while ttc from AF to OV but stopped each month at OV so please do stop now.
You can try it again post-40 weeks to try to help kickstart labor, though I've heard
If pregnancy doesn't automatically improve it, please talk to your health care professional about the psoriasis.
Anything you put on your skin can affect your baby, and yet there aren't warning labels on most skin products. So ask before you use anything, please. (Salicylic acid, for example is a no-no but you don't see warning labels on those creams.)
Anyway good luck and congrats on being pregnant!!
ETA: Lots of water can help skin problems too, I know -- but I had to deal with pg acne, not psoriasis, though it cleared up by 2nd trimester just fine. Hopefully your skin issues will clear up while pg -- it happens to many women
Mine was just the opposite *laughs*