Fetal duodenal obstructions: increased risk of prenatal sudden death.

OBJECTIVES: The aim of this study was to describe the outcome of fetuses with duodenal obstruction diagnosed prenatally and to compare the outcome with the results of studies of newborns.

METHODS: All fetuses with a prenatal diagnosis of duodenal obstruction were registered and evaluated prospectively from January 1985 to December 2000.

RESULTS: Duodenal obstruction was found in 29 fetuses at a mean gestational age of 29+2 weeks. Polyhydramnios was found in 24 cases (83%). Six fetuses (21%) had trisomy 21. Associated anomalies, including trisomy 21, were found in 18 cases (62%). Four fetuses with normal karyotype died in utero at 31-35 gestational weeks. Two of them had associated anomalies, but the anomalies could not explain the prenatal deaths and the deaths occurred suddenly and unexpectedly. Three infants died postnatally; all three had associated anomalies. Four infants with normal karyotype had neurological impairment suggesting that they might have had intrauterine asphyxia.

CONCLUSIONS: The present study indicates that duodenal obstruction is a more serious condition than previously believed, with an increased risk of prenatal asphyxia and death, even when the karyotype is normal and no associated anomalies are present. We consider the possibility that it could be caused by bradycardia/asystole following vagal overactivity due to distension of the upper gastrointestinal tract.