1. Section of Perinatal Pathology, Department of Pathology, Karolinska University Hospital Huddinge, Stockholm, Sweden
2. Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
3. Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
4. Department of Obstetrics and Gynecology, Karolinska University Hospital, Stockholm, Sweden