Cystic fibrosis trait is localized on the long arm of chromosome 7. It inserts into the cell membrane and is believed to function as an anion pump regulator. The most common gene mutation results in a deletion of phenylalanine amino acid 508, within one of the ATP binding sites. There are more than 50 less common mutations of the gene which account for the remainder of cystic fibrosis cases. There is a paucity of information regarding the natural history of meconium peritonitis, with or without pseudocyst formation, diagnosed in utero.
Therapy is empiric.
Since some cases improve and may even resolve in utero, most authors recommend expectant management, unless the fetus develops rapidly progressive ascites or other signs of compromise 8 . In the neonate with meconium peritonitis, the perforation may either have sealed off completely in utero, may seal off in the neonatal period, or may require surgical repair. Prior to labor, meconium is sterile, so that perforation does not translate into bacterial contamination. However, this can occur after delivery. Necrotizing enterocolitis, to our knowledge, has not been previously reported in meconium ileus, perforation in meconium ileus or in perforation in cystic fibrosis.