Chorioamnionitis and serum IgM in Wilson-Mikity syndrome.

A total of 753 infants weighing less than 1800 g at birth were studied prospectively and their serum IgM concentrations measured within 72 hours of age. Placentas from 584 of these infants were examined histologically for chorioamnionitis. The results were correlated with chronic respiratory insufficiency. Altogether 101 infants developed chronic respiratory insufficiency of which 22 had bronchopulmonary dysplasia and 35 Wilson-Mikity syndrome. The remaining 44 infants were classified as 'unexplained chronic lung disease'. Mean serum IgM concentration for Wilson-Mikity syndrome was 1.02 g/l whereas it was 0.14 g/l for bronchopulmonary dysplasia and 0.32 g/l for unexplained chronic lung disease. The incidence of chorioamnionitis was significantly higher in Wilson-Mikity syndrome (30/35) compared with bronchopulmonary dysplasia (4/16) and with infants without chronic respiratory insufficiency (145/490). Wilson-Mikity syndrome was shown to be significantly correlated with the evidences of intrauterine inflammation.