Relation of the site of congenital upper gastrointestinal obstruction to amniotic fluid bilirubin concentration.

Abstract

AbstractIn order to ascertain relative amniotic fluid bilirubin concentrations and to assess their value in antenatal diagnosis of upper gastrointestinal obstruction, amniotic fluid samples obtained from eight women who gave birth to infants with congenital upper gastrointestinal obstruction were analyzed spectrophotometrically.Types of congenital upper gastrointestinal obstruction in the study included esophageal atresia (1), pyloric atresia (1), high jejunal atresia (1), annular pancreas (2), and duodenal atresia (3).Amniotic fluid bilirubin concentration of the six women who gave birth to infants with intestinal obstruction distal to Vater's ampulla increased above the mean + 2 S.D. of the control. By contrast, the two who gave birth to infants with esophageal atresia or pyloric atresia had normal levels of amniotic fluid bilirubin.These findings suggest that when the obstruction is distal to Vater's ampulla, bile is regurgitated into the amniotic fluid by the fetus, resulting in a significant increase in amniotic bilirubin concentration. However, amniotic fluid bilirubin doesn't originate from the upper gastrointestinal tract in normal pregnancies: its concentration was within the normal range in the two fetuses with esophageal or pyloric atresia who couldn't regurgitate bile into the amniotic fluid.