Dr. Joseph H. Lyons: This 1-month-old male infant weighed 4.3 kg (9 lb 61/2 oz) at birth. The mother was a healthy 23-year-old primipara, and the 42-week pregnancy was not remarkable except for a tooth abscess early in the first trimester which was treated with antibiotics for three weeks. Labor lasted 1 1/2 hours, and there was a normal vaginal delivery with the use of general anesthesia. While still in the hospital, the mother was told that the infant had a large abdomen; it was explained to her that this was because of weak abdominal muscles. The neonatal period was uneventful, and the abdomen did not change in appearance. At the one-month "well-baby visit" the family physician noted the large abdomen, and the infant was referred to the Massachusetts General Hospital. On admission the baby was well-developed, active, and in no distress. His weight was 5.5 kg (12 3/4 lb).