Microbial Invasion of Amniotic Cavity and Histologic Chorioamnionitis in the Presence or Absence of Labor in Women at Term with Intact Membranes

Abstract

ABSTRACT
Background: Chorioamnionitis is a major cause of maternal and neonatal morbidity.
Inflammation has been implicated in the mechanisms responsible for preterm and term
parturition, as well as fetal injury.
Objective: To determine whether the presence and the progress of labor are associated
with an increase risk of microbial invasion to amniotic cavity, intraamniotic
inflammation and histologic chorioamnionitis in pregnant women at term with intact
membranes.
Methods: A case series comparative study conducted in Al-Kadymia Teaching Hospital
from May 2010 to May 2011. A total of 163 singleton pregnant women at term with
intact membrane were enrol l ed and divided into 3 groups: women not in labor, women
in early labor (cervical dilatation <4 cm), women in active labor, (cervical dilatation >4 cm).
Amniotic fluid w a s o b t a i n e d a n d s e n t for white blood cell count and microbial
culture, a n d t h e placenta, fetal membranes and umbilical cord sent for histopathology.
Results: The frequency of microbial invasion to amniotic cavity was 2.1% in women
not in labor, 3.9% in women with early labor and 22.2% in women with active labor.
Intra-amniotic inflammation was 6.4% in women not in labor, 9.8% in women with
early labor and 61.1% in women with active labor. Histological chorioamnionitis was
4.2% in women not in labor, 11.7% in women with early labor and 33.3% in women with
active labor.
Conclusions: In pregnant women at term with intact membranes, there is increased
risk of microbial invasion to amniotic cavity, intra-amniotic inflammation and histologic
chorioamnionitis in the presence of labor and advanced cervical dilatation.
Keywords: Amniotic fluid infection, Chorioamnionitis, Labour, Term pregnancy.