A case-control study of histological chorioamnionitis and neonatal infection.

The authors report a prospective study of the correlation between histopathological alterations in the placenta and the umbilical cord and neonatal infection in 223 newborns. The pathological studies were specifically concerned with the presence of infection as shown by a polymorphonuclear infiltrate at these sites. Inflammatory lesions were demonstrated in 26.9% of specimens and were highest in those with prolonged premature rupture of membranes and in the least mature placentas. Among the cases of histological chorioamnionitis, only 23.3% of infants had documented infection. Neonatal infection was diagnosed in 7.2% of the newborns and was 10 times more frequent in preterm newborns. Among the cases of infected newborns, 87.5% of placentas had histological chorioamnionitis. Pneumonia and septicemia were the most frequent conditions found among infected newborns. There was a strong correlation between histological chorioamnionitis and neonatal infection. The data obtained in this investigation suggest that histological chorioamnionitis is an important indicator of neonatal infection.