Fetal pyelectasis: a possible association with Down syndrome.

Two hundred ten consecutive fetuses were identified as having renal pyelectasis among 7400 patients scanned during 1 year. Seven of these 210 fetuses had Down syndrome. We reviewed images of the kidneys of 44 fetuses with Down syndrome collected over 5 years and found that 25% of these affected fetuses had pyelectasis. The incidence of Down syndrome was 3.3% when fetal pyelectasis was present.