Affiliation: | a Department of Medical Epidemiology and Biostatistics, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden b Unit of Clinical Epidemiology, Department of Medicine, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden c Division of Obstetrics and Gynecology, Department of Clinical Sciences, Karolinska Institutet Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden. |