Fetal Duodenal Obstructions: Increased Risk of Prenatal Sudden Death

Abstract

The most common form of bowel obstruction in newborn infants, with an estimated incidence of 1 in 10,000 live births, is congenital duodenal stenosis or atresia. Most often the second and third parts of the duodenum are affected. Outcomes have improved in recent years. The investigators looked at 29 fetuses given a prenatal diagnosis of duodenal obstruction and followed up prospectively from 1985 to 2000. Only three of these infants were identified in the second trimester; the mean gestational age at diagnosis was 29 weeks. Polyhydramnios was present in 24 cases (83%), and amniotic fluid was drained in half of them. Trisomy 21 was documented in six instances. About 60% of infants had other anomalies. One pregnancy was terminated, and there were four intrauterine fetal deaths at 31 to 35 weeks' gestation. Twenty-four infants were born alive, 10 of them delivered by cesarean. Signs of fetal distress were noted during labor in 29% of these cases. All but 2 of the 24 infants were operated on, most often undergoing duodeno-duodenostomy. One of the infants who did not undergo surgery died of heart failure, and the other lacked clinical signs of obstruction at birth. Three infants, all with associated anomalies, died postnatally. Two surviving infants had severe neurological impairment, and two others had impaired psychomotor development, Only six infants, 21% of the total, had a normal karyotype, no associated anomalies, and developed as normal neonates (Table 1). Prenatally diagnosed duodenal obstruction is a serious disorder. Even fetuses with a normal karyotype and no other anomalies are at risk of prenatal asphyxia and death. One possibility is that a distended upper gastrointestinal tract causes vagal overactivity and consequent bradycardia or asystole, resulting in fetal asphyxia.