I've got this too. So bad my legs have bloody scratched bits where I've been clawing at them in my sleep. Have had it since about 15 weeks and have mentioned it to quite a few midwives and doctors and all have seemed unconcerned - just blamed it on hormones and preggy weirdness. Midwife noticed the scratch marks on my belly today and said that she'd heard of a particular cream that really helped but couldn't remember he name. She said that she'd ask the woman who recommended it and text me, so I'll pop back and let you know.