1. Department of Obstetrics, Division of Obstetrics and Gynecology, Oslo University Hospital, Oslo, 0424Norway
2. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, 0372Norway
3. Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, 0372Norway
4. Centre for Biostatistics and Epidemiology, Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, 0372Norway
5. Institute of Cancer Genetics and Informatics, Oslo University Hospital, Oslo, 0379Norway
6. Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Colorado 80045, USA
7. Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Colorado 80045, USA
8. Department of Fetal Medicine, Division of Obstetrics and Gynecology, Oslo University Hospital, Oslo, 0424Norway