Affiliation: | (1) Division of Prenatal Medicine, Department of Obstetrics and Gynecology, Medical University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany e-mail: DrMartinKrapp@web.de Tel.: ++49-451-5002155, Fax: ++49-451-5002192, DE;(2) Institute of Social Medicine, Medical University of Lübeck, DE |