We are most grateful to all our advisors:

Mr Roy Farquharson Consultant in Obstetrics & Gynaecology, Liverpool Women’s Hospital

Ms Diana Hamilton-Fairley Consultant in Obstetrics & Gynaecology, Guys and St Thomas’s Hospital, London

Dr Marjory MacLean Consultant Obstetrician, Ayrshire Maternity Unit, Crosshouse, Kilmarnock

Prof Lesley Regan Professor of Obstetrics & Gynaecology, Imperial College & St Mary’s Hospital, London

Prof James Walker Professor of Obstetrics & Gynaecology, Leeds University & St James’s Hospital, Leeds