Clinical significance of histologic chorioamnionitis with a negative amniotic fluid culture in patients with preterm labor and premature membrane rupture

<div><p>Objective</p><p>To evaluate the effect of histological chorioamnionitis (HCA) with a negative amniotic fluid (AF) culture on adverse pregnancy and neonatal outcomes and inflammatory status in the AF compartment in women with preterm labor or preterm premature rupture of membranes (PPROM).</p><p>Methods</p><p>This is a retrospective cohort study of 153 women diagnosed as having a preterm labor or PPROM (20–34 weeks) who delivered singleton gestations within 48 hours of amniocentesis. AF obtained through amniocentesis was cultured, and interleukin (IL)-6, IL-8, and metalloproteinase-9 (MMP-9) levels were determined. The placentas were examined histologically.</p><p>Results</p><p>The prevalence of HCA with negative AF culture was 23.5% (36/153). The women with HCA but with a negative AF culture (group 2) and those with a positive AF culture (group 3) had a significantly lower mean gestational age at amniocentesis and delivery than those with a negative AF culture and without HCA (group 1). Women in group 3 had the highest levels of AF IL-6, IL-8, and MMP-9, followed by those in group 2, and those in group 1. Composite neonatal morbidity was significantly higher in groups 2 and 3 than in group 1, but this was no longer significant after adjusting for confounders caused mainly by the impact of gestational age.</p><p>Discussion</p><p>In the women who delivered preterm neonates, HCA with a negative AF culture was associated with increased risks of preterm birth, intense intra-amniotic inflammatory response, and prematurity-associated composite neonatal morbidity, and its risks are similar to the risk posed by positive AF culture.</p></div

Neonatal outcome of the study population according to the results of the placental histological examination and Amniotic Fluid (AF) culture^a

<p>Neonatal outcome of the study population according to the results of the placental histological examination and Amniotic Fluid (AF) culture<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0173312#t003fn003" target="_blank">^a</a></p

Amniotic Fluid (AF) Interleukin (IL)-6, IL-8, and Metalloproteinase-9 (MMP-9) levels of the study population according to the results of the placental histological examination and AF culture.

<p>AF IL-6, IL-8, and MMP-9 levels were lowest in women with a negative AF culture without histologic chorioamnionitis (HCA) (group 1), followed by those with HCA but a negative AF culture (group 2), and highest in those with a positive AF culture (group 3) (AF IL-6: group 1, median, 0.509 ng/mL [range, 0.004–11.825 ng/mL] vs. group 2, median, 2.842 ng/mL [range, 0.047–59.934 ng/mL] vs. group 3, median, 17.839 ng/mL [range, 0.009–104.121 ng/mL]; AF IL-8: group 1, median, 0.318 ng/mL [range, 0.012–11.492 ng/mL] vs. group 2, median, 1.348 ng/mL [range, 0–52.335 ng/mL] vs. group 3, median, 21.253 ng/mL [range, 0.046–113.969 ng/mL]; AF MMP-9: group 1, median, 0.593 ng/mL [range, 0–87.920 ng/mL] vs. group 2, median, 1.572 ng/mL [range, 0–2267.941 ng/mL] vs. group 3, median, 99.232 ng/mL [range, 0–2303.970 ng/mL]; each <i>P</i>-value is shown on the graph).</p

Frequency and clinical significance of short cervix in patients with preterm premature rupture of membranes

<div><p>Objective</p><p>Cervical length measurement has been uggested as a useful tool for predicting intra-amniotic infection/inflammation in preterm labor, but little information is available in the setting of preterm premature rupture of membranes (pPROM). We aimed to determine whether a short cervical length is independently associated with an increased risk of intra-amniotic infection or inflammation and impending preterm delivery in women with pPROM.</p><p>Methods</p><p>This was a retrospective cohort study involving 171 consecutive singleton pregnant women with pPROM (21+0–33+6 weeks’ gestation), who underwent amniocentesis. Amniotic fluid (AF) was cultured, and assayed for interleukin (IL)-6 and IL-8. Cervical length was measured at the time of amniocentesis by transvaginal ultrasonography with an aseptic technique. Short cervical length was defined as a cervical length of ≤15 mm. Intra-amniotic infection was defined as a positive AF culture for microorganisms and intra-amniotic inflammation was defined as elevated AF concentrations of IL-6 or IL-8 (IL-6 ≥1.5 ng/mL and/or IL-8 ≥1.3 ng/mL).</p><p>Results</p><p>Fifty (29.2%) women had a sonographic cervical length of ≤15mm. On univariate analysis, short cervical length was associated with an increased risk for intra-amniotic infection and/or inflammation; no other parameters studied showed a significant association. Multivariable analyses indicated that short cervical length was significantly associated with a higher risk of impending preterm delivery (within 2 days of measurement, within 7 days of measurement, and before 34 weeks), and remained significant after adjustment for potential confounders.</p><p>Conclusion</p><p>In women with pPROM, short cervical length is associated with an increased risk for intra-amniotic infection/inflammation and associated with impending preterm delivery, independent of the presence of intra-amniotic infection/inflammation.</p></div