[1] Univ Schleswig Holstein, Dept Obstet & Gynaecol, Lubeck, Germany
[2] Med Univ Lubeck, Inst Canc Epidemiol, Lubeck, Germany
[3] Med Univ Lubeck, Inst Social Med, Lubeck, Germany
[4] Univ Schleswig Holstein, Dept Paediat, Lubeck, Germany
[5] UCL, Inst Child Hlth, London WC1N 1EH, England
[6] Endokrinologikum Hamburg, Reprod Med & Gynakol Endokrinol, Hamburg, Germany