1. Faculty of Medicine and Health; Maternal Health Care Unit; Örebro University; Örebro Sweden
2. Faculty of Medicine and Health; University Health Care Research Center; Örebro University; Örebro Sweden
3. School of Medical Sciences; Clinical Epidemiology and Biostatistics; Örebro University; Örebro Sweden
4. Unit of Biostatistics; Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden
5. Faculty of Medicine and Health; Department of Obstetrics and Gynecology; Örebro University; Örebro Sweden
6. Department of Women's and Children's Health; Academic Hospital; Uppsala Sweden