TOPICS: Duodenal atresia, Down syndrome, double bubble sign, polyhydramnios, amniotic fluid, pylorus, prenatal findings of duodenal atresia, postnatal findings of duodenal atresia, bilious vomiting, duodenum, jejunal atresia, ileal atresia, superior mesenteric artery (SMA) occlusion, prenatal findings of jejunal and ileal atresia, postnatal findings of jejunal and ileal atresia, bilious vomiting, apple-peel appearance