1 Department of Gynaecological Endocrinology and Reproductive Medicine, University Hospital of Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, Luebeck 23538, Germany.
2 Department of Gynaecological Endocrinology and Reproductive Medicine, University Hospital of Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, Luebeck 23538, Germany. Electronic address: Georg.Griesinger@uni-luebeck.de.