System used to describe esophageal atresia and tracheoesophageal fistulas in newborns. Group A, birth weight > 2500 g without associated major anomalies; group B, birth weight 1800 Ð 2500 without associated major anomalies; group C, birth weight < 1800 g with associated major anomalies. Presence of pneumonia moves patient into Ònext most severeÓ group.