[1] Lewisham Primary Care Trust, Dept Reprod Hlth Care, London SE5 7RN, England
[2] Southwark Primary Care Trust, Dept Reprod Hlth Care, London, England
[3] Guys Kings & St Thomass Sch Med, Dept Obstet & Gynaecol, London SE1 9RT, England
[4] Southwark Primary Care Trust, Res Support Unit Primary & Community Care, London SE1 8RG, England