[1] Univ Ulm, Dept Obstet & Gynecol, D-89069 Ulm, Germany
[2] Univ Dusseldorf, Dept Obstet & Gynecol, D-40225 Dusseldorf, Germany
[3] Trauma Ctr Murnau, Dept Traumatol & Orthoped, Murnau, Germany
[4] Univ Dusseldorf, Dept Anaesthesiol, D-40225 Dusseldorf, Germany
[5] St Elizabeth Hosp, Dept Obstet & Gynecol, Cologne, Germany