Congenital anatomical defects of the gastrointestinal system

Abstract

Atresias are the most common of the gastro-intestinal anomalies. Embryologically they are usually attributed to a defect of re-canalisation of the rapidly proliferating gut, as usually occurs in oesophageal and duodenal atresias, or to vascolar anomaly disrupting development as is usually the case in jejunal atresias. However, epidemiological studies indicate that gastro-intestinal anomalies have a complex aetiology. In a study of congenital anomalies over a ten year period 1984 to 1994, 30% of recorded anomalies were oesophageal atresia, often accompanied by tracheo-oesophageal fistula, 30% were anorectal anomalies with or without recto-vesical fistula, 20% were intestinal atresia and 10% other gastro-intestinal anomalies including Hirshsprung disease, duplication or malrotation of the gut. Analysis of the results indicated that there was a prevalence of males exceeding 60% in most categories. There was a low birth weight in relation to gestational age in oesophageal and ano-rectal atresia but not in intestinal atresia. There was a bi-modal distribution of maternal age for oesophageal and ano-rectal atresia with significantly increased risks for mothers below 25 -and above 36 years. There was also a high frequency of associated anomalies which were present in 25% of the babies with oesophageal anomalies, 30% with intestinal atresias and 42% with anorectal anomalies. There was a high correlation between duodenal atresia and cJu·omosomal anomalies but jejunal atresia usually occurred as an isolated anomaly.