Trisomy 13 and trisomy 18 in a defined population: epidemiological, genetic and prenatal observations

Abstract

The introduction of a highly sensitive prenatal diagnostic screening programme would have a major impact on the timing and proportions of all trisomy 13 and 18 cases diagnosed in pregnancy as gauged by current practice. It is important that health professionals involved in prenatal counselling be aware that, as with Down syndrome and anencephaly, around 12% of prospective parents of a child with trisomy 13 or 18 choose to continue rather than terminate the pregnancy.