[1] Liverpool Womens Hosp, Dept Gynaecol Oncol, Dept, Liverpool L8 7SS, Merseyside, England
[2] Countess Chester Hosp, Dept Obstet & Gynaecol, Chester, Cheshire, England
[3] Wirral Univ, Teaching Hosp NHS Trust, Arrowe Pk Hosp, Dept Obstet & Gynaecol, Wirral, Merseyside, England