Abstract
Twenty-two placentas were investigated for the presence and patterns of
inflammation by extensive examination, and divided into four groups: 1) term
vaginal delivery [group I; n=6]; 2) term cesarean section delivery [group II;
n=5]; 3) preterm vaginal delivery [group III; n=4], and 4) preterm cesarean
section delivery [group IV; n=7]. In group I, all had deciduitis, and
choriodeciduitis/ chorionitis was present in two cases (33.3%). In group II,
four cases (80%) showed deciduitis and/or choriodeciduitis/chorionitis; three of
these had intact membranes. In group III, three cases (75%) showed deciduitis,
and two had chorionitis. In group IV, three cases (42.9%) showed no evidence of
inflammation, three had deciduitis and one had deciduitis/chorioamnionitis. In
all groups, membranitis was more severe, confined to the inner and mid segments
in general, and deciduitis, choriodeciduitis/chorionitis and chorioamnionitis
tended to overlap. The study newly demonstrates major characteristics of
placental inflammation: higher prevalence and severity of inflammation in the
inner segments of membrane and at the periphery of the placenta. Taking this
histotopography into account, it is desirable to take sections from the
placental margin, and the current concept of placental inflammation as a
surrogate marker of intrauterine infection should be reevaluated.