Meconium Blockage Syndrome

Abstract

The meconium blockage syndrome, also known as the meconium plug syndrome (1) or temporary meconium ileus (2), was described over a decade ago. The modern definition of the term was made by Clatworthy and his co-workers in 1956 when they noted that “newborn infants with intestinal obstruction due to the inability of the colon to rid itself of the meconium residue of nine months of fetal life are not uncommon.” The meconium blockage produces a clinical picture of mechanical obstruction in the newborn which is indistinguishable from other causes of low intestinal obstruction. It is not the same as meconium ileus, which occurs in 5 to 20 per cent of patients with cystic fibrosis and is associated with a deficiency of intestinal enzymes, producing thick, tenacious meconium in the jejunum and ileum (3–5). All prior reports have considered the meconium in meconium blockage as normal (6, 7). Clinical Features Forty-one cases of meconium blockage were reviewed. The maternal ages, parity, and complications of pregnancy or delivery were not different from the obstetric population as a whole. The 41 cases of meconium blockage occurred between January 1963 and January 1966. During this time there were approximately 10,000 deliveries a year at the Los Angeles County Hospital and 1,600 admissions to the premature center a year. The incidence of meconium blockage was approximately 1 in 1,000 admissions. The ratio of males to females was 2∶3, and 22 of the 41 infants were Negroes in a hospital where 50 per cent of the deliveries are in Negro women. Twenty-three per cent of the 34 infants born at the Los Angeles County Hospital were premature by birth weight, while the expected hospital premature rate is 13 per cent. Six other affected premature infants were admitted for care at the Premature Center, following birth elsewhere. There was no history of intestinal obstruction among siblings. Typically, the initial symptoms were green-stained vomitus and abdominal distention appearing between nine and eighty hours after birth in an otherwise normal infant. In one an early diagnosis was made at three hours of age after obstruction to passage of a rectal thermometer. In another infant, who passed his first meconium at the age of forty hours, the symptoms were not noticed until he was seven days old; these cleared at twelve days of age, following a barium enema. In 18 (48 per cent) of the infants one or more greenish-black meconium stools had been passed before the onset of symptoms. Fifteen (36 per cent) of the infants passed meconium in the first twenty-four hours. Abnormal physical findings were limited to early abdominal distention. As the distention progressed, lethargy, irritability, and respiratory distress developed in some of the infants, due to elevation of the diaphragm by the abdominal distention. Aspiration of gastric contents revealed a small volume of bile-stained gastric juices.