Is it necrotizing enterocolitis, microcolon of prematurity, or delayed meconium plug? A dilemma in the tiny premature infant.

Failure of a small premature newborn to adequately evacuate meconium for days or weeks has been attributed to "probable necrotizing enterocolitis (NEC)" or "microcolon of prematurity." The authors present an unusual type of "meconium plug syndrome" with the same clinical picture, seen in tiny premature babies (500 to 1,500 g), which required a contrast enema or Gastrografin upper gastrointestinal (UGI) series to evacuate the plugs. The obstruction resolved. Twenty babies (480 to 1,500 g) presented with the same clinical picture without any x-ray suggestion of NEC; contrast enemas were performed because of the suspicion of meconium plug syndrome. All 20 had extensive meconium plugs that were evacuated by the enema or by a Gastrografin UGI series. Most of them improved after the plugs were passed. These infants differ from typical full-term babies with meconium plug syndrome in a number of ways: (1) many of the mothers were on magnesium sulfate (MgSO4) or had eclampsia; (2) the plugs were diagnosed late rather than shortly after birth; and (3) the plugs were significant, extending to the right colon. The authors believe that when a tiny premature baby has findings consistent with meconium plug syndrome, the baby should be transported to radiology, for a Gastrografin enema, despite the difficulties involved. Delay postpones the start of feedings, and increases the number of radiographic studies.