I get the serum from my doctor, but I found alot of places that sell it if you google the name on the internet. It's not cheap - about 60 - 75 a bottle- but wow! it helped more than anything else for Acne because it contains estrogen/progesterone which balances testosterone, a big cause of Acne for me. If you're pregnant, Acne my be a hormonal imbalance?
I don't know about HA and pregnancy, but it seems pretty harmless. I would assume it couldn't hurt topically. I started using it on my skin and old red marks began fading. It actually helped heal a few wasp stings I received (welcome to spring) which usually stay with me forever if i don't get a cortisone injection. I have a feeling there's much more it helps; just the beginning.