When I was pregnant I was sent to the foetal medical unit as my babies femur was measuring small, and his growth had slowed down. I was really worried about a risk of Down's syndrome of dwarfism.
I read lots of threads on mumsnet from over the years from people in a similar situation, but rarely did the OP return to give the outcome.
So I thought I'd make this thread as I can't find my original- my baby had small femurs on scan, we had lots of worry, but all turned out fine. Baby just has little legs in proportion to his body.
Hope this helps someone!