Isolation of aerobic bacteria from the placenta.

Cultures for aerobic bacteria were prepared from 353 placentas. Specimens were taken from the chorion after removing the amnion. The specimens were immersed into Stuart transport medium. Microscopic examination of the placenta and cultures from the throat and ear of newborns were also done. The rate of positive bacterial cultures was 16%. Chorioamnionitis was found in 15%. The proportion of chorioamnionitis caused by aerobic bacteria was 44%. The rate of positive bacterial cultures from the placenta in the group of newborns with clinical signs of intrauterine infection was 63%. Bacteria can be present on the chorionic plate without any histological evidence of chorioamnionitis. Bacteriological examination of the placenta is therefore mandatory when amniotic fluid infection is suspected.