1. Impact of a new national screening policy for Down's syndrome in Denmark: population based cohort study;Ekelund;BMJ,2008
2. Danish National Board of Health Report from a working commission. Prenatal diagnosis and risk assessment Copenhagen Danish National Board of Health 2003
3. A measure of informed choice;Marteau;Health Expect,2001
4. Live births by region, mothers ancestry, mothers country of origin, mothers citizenship, age of mother and sex of child http://www.dst.dk/da/Statistik/emner/foedsler-og-adoptioner/foedsler.html