I used to work with Philip Davies who is the founder of Glow - there are two branches, one on Motcomb Street and one on Pimlico Road and they have a full range of dedicated maternity treatments.
Philip specialises in Maternity and in case the idea of going to a man feels less comfortable than a woman, I totally recommend him - I've known him for around six years and he's always had lots of regular female clients coming to him for pre / post maternity and fertility. He's really warm and friendly, so I would imagine it would be fine to give him and ring and have a brief chat to find out more beforehand. Feel free to message me direct if you would like any more info.
http://www.glowurbanspa.co.uk/baby_Baby_Pre.asp
Zoe