Prenatal classes I can do in North London?
I think you are probably best of with Yoga or Pilates. Nice and gentle but you can get a decent stretch. I think when you are pregnant though, you mainly want to stay away from the high intensity stuff.
I'm 6 months pregnant and I have been going to Omnida Studios in Turnpike Lane. They offer a prenatal/postnatal class and I always feels a lot better afterwards particularly after a bad night of back pain. It's every Tuesday at 11am. Studios are brand new and really lovely.
Their website is www.omnida.co.uk
Best of luck with everything!