[1] Univ Leicester, Dept Hlth Sci, Leicester, Leics, England
[2] Univ Latvia, Dept Obstet & Gynecol, Riga, Latvia
[3] Keele Univ, Sch Psychol, Newcastle Under Lyme, England
[4] Royal Stoke Univ Hosp, Dept Gynecol, Stoke On Trent, England
[5] Riga Stradins Univ, Dept Obstet & Gynecol, Riga, Latvia
[6] Univ Leicester, Dept Canc Studies, Leicester, Leics, England