Prenatal treatment of meconium peritonitis with urinary trypsin inhibitor.

We describe a case of congenital meconium peritonitis with progressive fetal ascites and polyhydramnios. Fetal ascites could be only partially reduced on paracentesis at 29 weeks' gestation, and it subsequently increased. Urinary trypsin inhibitor (UTI), a physiological anti-inflammatory substance, was administered into the fetal abdominal cavity at a second paracentesis performed at 35 weeks' gestation. There was a significant amount of fetal ascites remaining 1 day after the second paracentesis, but this completely resolved within 5 days. A healthy infant was delivered vaginally and no surgical intervention was required. The case suggests that UTI can reduce meconium-induced chemical peritonitis and thereby facilitate intrauterine remission of fetal ascites.