Abnormally invasive placenta-prevalence, risk factors and antenatal suspicion: results from a large population-based pregnancy cohort study in the Nordic countries. - Thurn, L; Lindqvist, PG; Jakobsson, M; Colmorn, LB; Klungsoyr, K; Bjarnadóttir, RI; Tapper, AM; Børdahl, PE; Gottvall, K; Petersen, KB; Krebs, L; Gissler, M; et al. (BJOG: An International Journal of Obstetrics & Gynaecology, 2016)