Clinical significance of intra-amniotic inflammation in patients with preterm premature rupture of membranes.
OBJECTIVE
This study was conducted to determine the frequency and clinical significance of intra-amniotic inflammation in patients with preterm premature rupture of the membranes.


METHODS
Amniotic fluid was retrieved from 219 patients with preterm premature rupture of the membranes; the fluid was cultured for aerobic and anaerobic bacteria and mycoplasmas and assayed for neutrophil collagenase, which is also known as matrix metalloproteinase-8. Matrix metalloproteinase-8 was used because previous studies indicated that this was a sensitive and specific index of inflammation and that is correlated with the amniotic fluid white blood cell count. Intra-amniotic inflammation was defined as an elevated amniotic fluid matrix metalloproteinase-8 concentration (>23 ng/mL). Nonparametric and survival techniques were used for statistical analysis.


RESULTS
The overall rate of intra-amniotic inflammation was 42% (93/219 samples); proven intra-amniotic infection was detected only in 23% (50/219 samples). Intra-amniotic inflammation with a negative amniotic fluid culture for micro-organisms was found in 23% (51/219 samples) and was as common as proven intra-amniotic infection. Pregnancy outcome was worse in patients with intra-amniotic inflammation and a negative culture than in those patients with a negative culture and without inflammation. There were no differences in the interval-to-delivery or rate of complications between patients with intra-amniotic inflammation and a negative culture and patients with proven amniotic fluid infection.


CONCLUSIONS
We conclude that intra-amniotic inflammation, regardless of culture result, is present in 42% of patients with preterm premature rupture of the membranes and that it is a risk factor for impending preterm delivery and adverse outcome. We propose that intra-amniotic inflammation, rather than infection, be used to classify and treat patients with preterm premature rupture of the membranes.
Shim
Soon-Sup
SS
Department of Obstetrics and Gynecology, Laboratory of Fetal Medicine Research, College of Medicine, Seoul National University Seoul 110-744, Korea.
Romero
Roberto
R
Hong
Joon-Seok
JS
Park
Chan-Wook
CW
Jun
Jong Kwan
JK
Kim
Beyong Il
BI
Yoon
Bo Hyun
BH
D000328:Adult; D000653:Amniotic Fluid / Q000382:microbiology; D002821:Chorioamnionitis / Q000453:epidemiology; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology*; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology; D020784:Matrix Metalloproteinase 8 / Q000032:analysis; D007752:Obstetric Labor, Premature / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D012307:Risk Factors
D020784:Matrix Metalloproteinase 8