Affiliation: | 1. Department of Obstetrics and Gynecology, Vrinnevi Hospital, Norrk?ping, Sweden;2. Department of Medical and Health Sciences, Link?ping University, Link?ping, Sweden;3. Department of Obstetrics and Gynecology, Link?ping University, Link?ping, Sweden;4. Department of Clinical and Experimental Medicine, Link?ping University, Link?ping, Sweden |