Anna Olsson1,2, Vladimir Radulovic1,2, Ulla-Britt Wennerholm3,4. 1. Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. 2. Department of Haematology and Coagulation, Sahlgrenska University Hospital, Gothenburg, Sweden. 3. Perinatal Centre, Department of Obstetrics and Gynaecology, Institute of Clinical Science, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden. 4. Department of Obstetrics and Gynaecology, Sahlgrenska University Hospital/East, Gothenburg, Sweden.