1. Department of Surgery, Oulu University Hospital and University of Oulu, Oulu, Finland;
2. Division of Operative Care and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland;
3. Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden;
4. Department of Children and Adolescents, Oulu University Hospital and University of Oulu, Oulu, Finland