The Involvement of Human Amnion in Histologic Chorioamnionitis is an Indicator that a Fetal and an Intra-Amniotic Inflammatory Response is More Likely and Severe: Clinical Implications

ObjectiveAmnionitis (inflammation of the amnion) is the final stage of extra-placental chorioamniotic inflammation. We propose that patients with “amnionitis”, rather than “chorionitis” have a more advanced form of intra-uterine inflammation/infection and, thus, would have a more intense fetal and intra-amniotic inflammatory response than those without “amnionitis”.Study designThe relationship between the presence of amnionitis, and a fetal and an intra-amniotic inflammatory response was examined in 290 singleton preterm births (≤36 weeks) with histologic chorioamnionitis. The fetal inflammatory response was determined by plasma C-reactive protein (CRP) concentrations in umbilical cord and the presence of funisitis. The intra-amniotic inflammatory response was assessed by matrix metalloproteinase-8 (MMP-8) concentration and white blood cell (WBC) count in 156 amniotic fluid (AF) samples obtained within 5 days of birth. AF was cultured for aerobic and anaerobic bacteria and genital mycoplasmas. The CRP concentration was measured with a highly sensitive immunoassay.Results(1) Amnionitis was present in 43.1% of cases with histologic chorioamnionitis. (2) Patients with amnionitis had a significantly higher rate of funisitis and positive AF culture and a higher median umbilical cord plasma CRP, AF MMP-8 level and AF WBC count than those without amnionitis (p < 0.001 for each). (3) Among cases with amnionitis, the presence or absence of funisitis was not associated with significant differences in the median cord plasma CRP, AF MMP-8 level and AF WBC count. (4) However, the presence of amnionitis in cases with funisitis was associated with a higher median umbilical cord plasma CRP, AF MMP-8 level and AF WBC count than the absence of amnionitis in those with funisitis (p < 0.05 for each). (5) Multiple logistic regression analysis demonstrated that amnionitis was a better independent predictor of proven or suspected early-onset neonatal sepsis (odds ratio 3.8, 95% confidence interval (CI) 1.1–13.2, p < 0.05) than funisitis (odds ratio 1.8, 95% CI 0.5–6.1, not significant) after correction for the contribution of other potential confounding variables.ConclusionThe involvement of the amnion in the inflammatory process of the extraplacental membranes is associated with a more intense fetal and intra-amniotic inflammatory response than chorionitis alone. This observation has clinical implications because it allows staging of the severity of the inflammatory process and assessment of the likelihood of fetal involvement.     

An elevated maternal serum C-reactive protein in the context of intra-amniotic inflammation is an indicator that the development of amnionitis,an intense fetal and AF inflammatory response are likely in patients with preterm labor: clinical implications

Abstracts

Objective: We propose that an elevated maternal serum C-reactive protein (CRP) concentration in the context of intra-amniotic inflammation (IAI) is a predictor for amnionitis development, known to be the most advanced stage of maternal inflammatory response during the progression of acute histologic chorioamnionitis in preterm gestations.

Methods: Study population consisted of 53 singleton gestations with IAI, who underwent amniocentesis due to preterm labor and intact membranes (PTL) and delivered preterm-neonates (<34.5 weeks) within 5?days of amniocentesis. The frequency of amnionitis and the intensity of fetal and amniotic fluid (AF) inflammatory response were examined according to the presence or absence of an elevated maternal serum CRP (≥0.7?mg/dL) at the time of amniocentesis. IAI was defined as an elevated AF matrix metalloproteinase-8 (MMP-8) (≥23?ng/mL), and fetal inflammatory response syndrome (FIRS) defined as an elevated umbilical cord plasma CRP (≥200?ng/mL).

Results: (1) Patients (73.6%, 39/53) with an elevated maternal serum CRP had a significantly higher rate of amnionitis (59.0% versus 7.1%; p?<?0.005), but not funisitis (46.2% versus 28.6%; p?>?0.05), and higher median AF MMP-8 and umbilical cord plasma CRP concentration at birth than patients (26.4%,14/53) without that (AF MMP-8 (ng/mL): 373.1 versus 138.6: p?=?0.05; umbilical cord plasma CRP (ng/mL): 363.4 versus 15.5: p?<?0.05); (2) Multiple logistic regression analysis demonstrated that an elevated maternal serum CRP was a better independent predictor of amnionitis (odds ratio (OR), 12.5: 95% confidence interval (CI), 1.1–141.0; p?<?0.05) than FIRS (OR, 3.6: 95% CI, 0.6–20.2; p?=?0.150) and any other AF tests.

Conclusions: An elevated maternal serum CRP concentration in the context of IAI is an indicator that the development of amnionitis, an intense fetal and AF inflammatory response are likely in patients with PTL.     

The Frequency and Clinical Significance of Intra-Uterine Infection and Inflammation in Patients with Placenta Previa and Preterm Labor and Intact Membranes

ObjectiveHistologic placental and/or intra-amniotic inflammation is frequently documented during ascending intra-uterine infections in patients with preterm labor and intact membranes. Placenta previa can be a clinical situation that shows the successive schema of histologic placental and intra-amniotic inflammation during the process of ascending intra-uterine infections. However, a paucity of information exists about the frequency and clinical significance of intra-uterine infections and inflammation in patients with placenta previa and preterm labor and intact membranes. The purpose of this study was to examine this issue.Study designAmniocentesis was performed on 42 patients with placenta previa and preterm labor and intact membranes (gestational age < 37 weeks). Amniotic fluid (AF) was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and AF white blood cell (WBC) count and matrix metalloproteinase-8 (MMP-8) concentrations were determined. The diagnosis of intra-amniotic inflammation was made in patients with an elevated AF MMP-8 (≥23 ng/ml). Non-parametric statistics were used for analysis.Results1) Intra-amniotic inflammation was present in 16.7% (7/42), proven AF infection in 4.9% (2/41), and histologic chorioamnionitis in 19.0% (8/42) of patients with placenta previa and preterm labor; 2) Patients with intra-amniotic inflammation had significantly higher rates of a positive AF culture, histologic chorioamnionitis, funisitis, and a shorter interval-to-delivery than those without intra-amniotic inflammation (p < 0.05 for each); 3) Among patients with histologic chorioamnionitis, inflammation of the choriodecidua, which was exposed to the cervical canal, existed in all cases (8/8), but inflammation of the chorionic plate existed in 63% of patients (5/8); 4) Patients with inflammation of the chorionic plate had significantly higher median AF MMP-8 concentrations and WBC counts, and higher rates of intra-amniotic inflammation than those in whom inflammation was restricted to choriodecidua (p < 0.05 for each).ConclusionsPlacental inflammation was present in 19.0% and intra-amniotic inflammation was present in 16.7% of patients with placenta previa and preterm labor and intact membranes. The intra-amniotic inflammatory response was stronger when inflammation was present in the chorionic plate and choriodecidua, than when it was restricted to the choriodecidua only, which was exposed to the cervical canal in placenta previa.     

Comparison of rapid MMP-8 and interleukin-6 point-of-care tests to identify intra-amniotic inflammation/infection and impending preterm delivery in patients with preterm labor and intact membranes*

Objective: Among patients presenting with preterm labor and intact membranes, those with intra-amniotic inflammation have adverse obstetrical and neonatal outcomes. The diagnosis of intra-amniotic inflammation can easily be made by detecting an elevated concentration of the cytokine interleukin (IL)-6 or the enzyme neutrophil collagenase, also known as matrix metalloproteinase (MMP)-8. The diagnostic performances of MMP-8 and IL-6 enzyme-linked immunosorbent assay tests are similar. Recently, a rapid test has become available for point-of-care determination of either MMP-8 or IL-6. The objectives of this study were to compare the diagnostic indices and predictive values between the rapid MMP-8 and IL-6 tests for the identification of intra-amniotic inflammation in patients with preterm labor and intact membranes.

Materials and methods: We performed a retrospective cohort study including 124 women with singleton pregnancies who presented with symptoms of preterm labor and underwent transabdominal amniocentesis for the evaluation of microbial invasion of the amniotic cavity (MIAC). MIAC was defined according to amniotic fluid culture results (aerobic and anaerobic bacteria as well as genital Mycoplasmas). Amniotic fluid white blood cell (WBC) counts were determined using a hemocytometer chamber. An elevated amniotic fluid MMP-8 concentration was assessed using Yoon’s MMP-8 Check^® (cutoff: 10?ng/mL). An elevated amniotic fluid IL-6 concentration was scored when there was a positive result for the lateral flow-based immunoassay (cutoff: ≥745?pg/mL and ≥1000?pg/mL). In order to objectively compare rapid MMP-8 and rapid IL-6 tests to identify intra-amniotic inflammation, an amniotic fluid WBC count of ≥50 cells/mm³ was used to define intra-amniotic inflammation.

Results: (1) The rapid tests had the same sensitivity for the detection of intra-amniotic inflammation [85.7% (18/21) for all]; (2) the specificity of the rapid MMP-8 test was higher than that of the rapid IL-6 test (cutoff: 745?pg/mL) for the identification of intra-amniotic inflammation [72.8% (75/103) vs. 64.1% (66/103); p?Conclusion: We conclude that the rapid MMP-8 test has a better specificity than the rapid IL-6 (cutoff: 745?pg/mL) assay for the detection of intra-amniotic infection. Moreover, we observed that among patients who were not identified as having intra-amniotic infection or inflammation by the standard cultivation technique and amniotic fluid WBC count, those who had a positive MMP-8 rapid test delivered preterm and had acute histologic chorioamnionitis.     

The risk of intra-amniotic infection, inflammation and histologic chorioamnionitis in term pregnant women with intact membranes and labor

Objective

A previous study has demonstrated that term labor is associated with an increased risk of microbial invasion of the amniotic cavity, intra-amniotic inflammation and histologic chorioamnionitis. This study was performed to determine when the risk of intra-amniotic infection, inflammation and histologic chorioamnionitis begins to increase during the course of labor.

Study design

Amniotic fluid (AF) was obtained from 926 term singleton pregnant women with intact membranes during cesarean section. AF was cultured for aerobic, anaerobic bacteria and genital mycoplasmas. An AF white blood cell (WBC) count was determined. Patients were divided into five groups according to the absence or presence of regular uterine contractions and the degree of cervical dilatation. Intra-amniotic inflammation was defined as an AF WBC ≥19/mm³. Histologic chorioamnionitis was defined as the presence of acute inflammatory changes in the extra-placental membranes or the chorionic plate of the placenta, and funisitis was diagnosed in the presence of neutrophil infiltration into the umbilical vessel walls or Wharton’s jelly.

Results

(1) The more advanced the cervical dilatation, the greater the risk of intra-amniotic infection and/or inflammation and histologic chorioamnionitis; (2) The risk of intra-amniotic infection and/or inflammation increased after the cervix began to dilate (7.8% in group 1 [without regular uterine contractions] vs. 18.3% in group 2 [regular uterine contractions and cervical dilation ≤1 cm], p < 0.01); (3) however, histologic chorioamnionitis was significantly more common in women in group 3 than in group 2 (4.2% in group 2 [regular uterine contractions and cervical dilatation ≤1 cm] vs. 23.1% in group 3 [regular uterine contractions and a cervical dilatation of 2-3 cm], p < 0.05).

Conclusions

The risk of intra-amniotic infection and/or inflammation increases after the cervix begins to dilate and that of histologic chorioamnionitis increases after the cervix dilates 2 cm in term pregnant women with regular uterine contractions with intact membranes.     

Amniotic fluid interleukin-6 and tumor necrosis factor-α at mid-trimester genetic amniocentesis: Relationship to intra-amniotic microbial invasion and preterm delivery

Objective

To determine the value of amniotic fluid interleukin-6 (AF IL-6) and tumor necrosis factor-α (AF TNF-α) in the diagnosis of microbial invasion of the amniotic cavity and in the prediction of preterm delivery (PTD).

Study design

Following amniocentesis, a sample of amniotic fluid was sent for aerobic and anaerobic bacterial cultures along with Ureaplasma urealyticum culture and it was also assessed for IL-6 and TNF-α.

Results

Forty-eight women who delivered preterm (<37 weeks) were matched with 96 controls. The AF IL-6 and TNF-α concentrations of women with spontaneous PTD were significantly higher than those who delivered at term (IL-6: 176.3 pg/ml [130.6–208.6] vs. 52.3 pg/ml [37.2–92.3]; TNF-α: 8.8 pg/ml [7.2–10.7] vs. 5.5 pg/ml [5.0–6.3]). AF IL-6 and TNF-α concentrations of >99.3 pg/ml and of >6.6 pg/ml respectively, had a sensitivity of 89.6% and 81.3% and a specificity of 80.3% and 79.2% for the prediction of spontaneous PTD. Moreover, AF IL-6 and TNF-α concentrations of >99.3 pg/ml and of 6.3 pg/ml respectively, had a sensitivity of 91.9% and 78.4% and a specificity of 73.8% and 70.1% for the prediction of a positive AF culture.

Conclusions

Elevated mid-trimester concentrations of AF IL-6, or/and of TNF-α can identify women at risk for intra-amniotic infection and for spontaneous PTD.     

Sterile and microbial-associated intra-amniotic inflammation in preterm prelabor rupture of membranes

Objective: The objectives of this study were to: (1) determine the amniotic fluid (AF) microbiology of patients with preterm prelabor rupture of membranes (PROM); and (2) examine the relationship between intra-amniotic inflammation with and without microorganisms (sterile inflammation) and adverse pregnancy outcomes in patients with preterm PROM.

Methods: AF samples obtained from 59 women with preterm PROM were analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital mycoplasmas) and with broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). AF concentration of interleukin-6 (IL-6) was determined using ELISA. Results of both tests were correlated with AF IL-6 concentrations and the occurrence of adverse obstetrical/perinatal outcomes.

Results: (1) PCR/ESI-MS, AF culture, and the combination of these two tests each identified microorganisms in 36% (21/59), 24% (14/59) and 41% (24/59) of women with preterm PROM, respectively; (2) the most frequent microorganisms found in the amniotic cavity were Sneathia species and Ureaplasma urealyticum; (3) the frequency of microbial-associated and sterile intra-amniotic inflammation was overall similar [ 29% (17/59)]: however, the prevalence of each differed according to the gestational age when PROM occurred; (4) the earlier the gestational age at preterm PROM, the higher the frequency of both microbial-associated and sterile intra-amniotic inflammation; (5) the intensity of the intra-amniotic inflammatory response against microorganisms is stronger when preterm PROM occurs early in pregnancy; and (6) the frequency of acute placental inflammation (histologic chorioamnionitis and/or funisitis) was significantly higher in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [93.3% (14/15) versus 38% (6/16); p?=?0.001].

Conclusions: (1) The frequency of microorganisms in preterm PROM is 40% using both cultivation techniques and PCR/ESI-MS; (2) PCR/ESI-MS identified microorganisms in the AF of 50% more women with preterm PROM than AF culture; and (3) sterile intra-amniotic inflammation was present in 29% of these patients, and it was as or more common than microbial-associated intra-amniotic inflammation among those presenting after, but not before, 24 weeks of gestation.     

Amniotic fluid matrix metalloproteinase-9 levels in women with preterm labor and suspected intra-amniotic infection.

OBJECTIVE: To determine the accuracy of amniotic fluid (AF) matrix metalloproteinase-9 measurements for diagnosing intra-amniotic infection in women with preterm labor. METHODS: We performed amniocenteses in 44 women between 22 and 35 weeks' gestation who presented to our center with preterm labor and clinical suspicion of intra-amniotic infection. Each sample was analyzed by glucose measurement, Gram stain, and culture for aerobes, anaerobes, and mycoplasmas. We tested the AF for matrix metalloproteinase-9 using gelatin zymography and a commercial enzyme-linked immunosorbent assay (ELISA) system. We calculated accuracy and confidence intervals (CIs) for AF matrix metalloproteinase-9, glucose, and Gram stain for diagnosing intra-amniotic infection, using culture as the criterion standard. RESULTS: All patients who had matrix metalloproteinase-9 detectable by ELISA also demonstrated matrix metalloproteinase-9 by zymography. Six cases of intra-amniotic infection were confirmed by culture (prevalence 14%). The performance statistics of AF matrix metalloproteinase-9 for diagnosing intra-amniotic infection were: sensitivity 83% (95% CI 53, 99), specificity 95% (95% CI 88, 99), positive predictive value 71% (95% CI 37, 99), and negative predictive value 97% (95% CI 92, 99). Two women had false-positive results; one had gram-negative rods on the AF Gram stain and developed clinical signs and symptoms of chorioamnionitis several hours after amniocentesis and the other had a purulent vaginal discharge and an AF glucose level less than 15 mg/dL. Both delivered within 24 hours of amniocentesis. CONCLUSION: Measuring matrix metalloproteinase-9 in the AF appeared to be reliable for diagnosing intra-amniotic infection. An elevated matrix metalloproteinase-9 concentration in the AF at a preterm gestational age may portend imminent delivery regardless of microbiologic confirmation of intra-amniotic infection.     

The relationship between the intensity of intra-amniotic inflammation and the presence and severity of acute histologic chorioamnionitis in preterm gestation

Objective: Acute histologic chorioamnionitis (HCA) is associated with an increased risk of perinatal mortality and morbidity. The purpose of this study was to determine the relationship between the intensity of intra-amniotic inflammation (IAI) and the severity of acute HCA in preterm gestation.

Methods: The relationship between the intensity of IAI and the presence and severity of acute HCA was examined in 412 patients with singleton gestations who delivered within 120?h of transabdominal amniocentesis. The concentration of amniotic fluid (AF) matrix metalloproteinase (MMP)-8 was assayed to determine the presence and intensity of IAI. Acute HCA was defined as the presence of inflammatory change in any tissue samples according to the criteria previously reported. The total grade of acute HCA was used to determine the severity of HCA.

Results: (1) Patients with IAI had a significantly higher rate of acute HCA than those without IAI [76.9% (133/173)] versus 20.9% (50/239), p?p?p?Conclusions: AF MMP-8 concentration was not only a predictor of the presence of acute HCA, but its concentration also correlated with the severity of acute HCA. The higher the intensity of IAI, the worse the degree of acute HCA in preterm gestation.     

An elevated amniotic fluid prostaglandin F2α concentration is associated with intra-amniotic inflammation/infection,and clinical and histologic chorioamnionitis,as well as impending preterm delivery in patients with preterm labor and intact membranes

Objective: To determine whether an elevated amniotic fluid concentration of prostaglandin F_2α (PGF_2α) is associated with intra-amniotic inflammation/infection and adverse pregnancy outcomes in patients with preterm labor and intact membranes.

Materials and methods: The retrospective cohort study included 132 patients who had singleton pregnancies with preterm labor (<?35 weeks of gestation) and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as for genital mycoplasmas. Intra-amniotic inflammation was defined by an elevated amniotic fluid matrix metalloproteinase-8 (MMP-8) concentration (>23?ng/mL). PGF_2α was measured with a sensitive and specific immunoassay. The amniotic fluid PGF_2α concentration was considered elevated when it was above the 95th percentile among pregnant women at 15–36 weeks of gestation who were not in labor (≥170?pg/mL).

Results: (1) The prevalence of an elevated amniotic fluid PGF_2α concentration was 40.2% (53/132) in patients with preterm labor and intact membranes; (2) patients with an elevated amniotic fluid PGF_2α concentration had a significantly higher rate of positive amniotic fluid culture [19% (10/53) versus 5% (4/79); p?=?0.019], intra-amniotic inflammation/infection [49% (26/53) versus 20% (16/79); p?=?0.001], spontaneous preterm delivery, clinical and histologic chorioamnionitis, and funisitis, as well as a higher median amniotic fluid MMP-8 concentration and amniotic fluid white blood cell count and a shorter amniocentesis-to-delivery interval than those without an elevated concentration of amniotic fluid PGF_2α (p?<?0.05 for each); and (3) an elevated amniotic fluid PGF_2α concentration was associated with a shorter amniocentesis-to-delivery interval after adjustment for the presence of intra-amniotic inflammation/infection [hazard ratio 2.1, 95% confidence interval (CI) 1.4–3.1; p?=?0.001].

Conclusion: The concentration of PGF_2α was elevated in the amniotic fluid of 40.2% of patients with preterm labor and intact membranes and is an independent risk factor for intra-amniotic inflammation/infection, impending preterm delivery, chorioamnionitis, and funisitis.     

Amniotic fluid soluble human leukocyte antigen-G in term and preterm parturition,and intra-amniotic infection/inflammation

Objective.?Circulating soluble human leukocyte antigen-G (sHLA-G) has been associated with pregnancy complications, and determination of sHLA-G concentrations in amniotic fluid (AF) has been reported in normal pregnancies. Our aim was to determine if the AF concentrations of sHLA-G change with advancing gestation, spontaneous labor at term, and in patients with spontaneous preterm labor (PTL) with intact membranes, as well as in those with preterm prelabor rupture of membranes (PROM), in the presence or absence of intra-amniotic infection/inflammation (IAI).

Study design.?This cross-sectional study included the following groups: (1) mid-trimester (n?=?55); (2) normal pregnancy at term with (n?=?50) and without (n?=?50) labor; (3) spontaneous PTL with intact membranes divided into: (a) PTL who delivered at term (n?=?153); (b) PTL who delivered preterm without IAI (n?=?108); and (c) PTL with IAI (n?=?84); and (4) preterm PROM with (n?=?46) and without (n?=?44) IAI. sHLA-G concentrations were determined by ELISA. Non-parametric statistics were used for analysis.

Results.?(1) Among patients with PTL, the median AF sHLA-G concentration was higher in patients with IAI than in those without IAI or women that delivered at term (p?<?0.001 for both comparisons); (2) Similarly, patients with preterm PROM and IAI had higher median AF sHLA-G concentrations than those without IAI (p?=?0.004); (3) Among patients with PTL and delivery, those with histologic chorioamnionitis and/or funisitis had a higher median AF sHLA-G concentration than those without histologic inflammation (p?<?0.001); and (4) The median AF sHLA-G concentration did not change with advancing gestational age.

Conclusions.?AF sHLA-G concentrations are elevated in preterm parturition associated to IAI as well as in histologic chorioamnionitis. We propose that sHLA-G may participate in the regulation of the host immune response against intra-amniotic infection.     

Identification of biomarkers for preterm delivery in mid-trimester amniotic fluid

Objective

We investigated whether the level of vascular endothelial growth factor (VEGF) and inflammatory markers in mid-trimester amniotic fluid have predictive value for spontaneous preterm birth in singleton pregnancy.

Method

Our subjects were 72 pregnant women who were undertaken with amniocentesis from 16 to 19 weeks of gestation. 36 cases were women with preterm delivery, and other 36 cases were matched women with full-term delivery. Stored amniotic fluid was investigated after the delivery. The levels of matrix metalloproteinases-8 (MMP-8), interleukin-6 (IL-6), C-reactive protein (CRP), and VEGF were measured by enzyme-linked immunosorbent assay (ELISA) and Western blot.

Results

The levels of MMP-8 and IL-6 in preterm group were significantly higher than control group (5.76 ± 1.53 ng/ml vs 4.89 ± 1.77 ng/ml and 170.54 ± 55.69 pg/ml vs 141.92 ± 57.21 pg/ml, respectively) (p < 0.05). In terms of VEGF, the levels were elevated in preterm group (30.76 ± 4.06 pg/ml vs 22.36 ± 7.03 pg/ml) (p < 0.05).

Conclusion

This study suggests that elevated levels of IL-6 and MMP-8 in amniotic fluid at mid-trimester are predictive of preterm delivery, and that VEGF which is representative of angiogenesis can be a new and useful predictor of preterm delivery.     

Amniotic fluid inflammation with negative culture and outcome after cervical cerclage

Objective: To determine whether amniotic fluid (AF) inflammation, in the absence of infection, is associated with adverse pregnancy outcomes in nonelective cervical cerclage patients. Methods: A retrospective case-control study was carried out. The patient population included 82 singleton pregnancies with negative AF cultures. The variables used to define AF inflammation were white blood cell count (WBC) >50 cell/mm³, glucose <14?mg/dl or interleukin-6 (IL-6) >11.3?ng/ml. The study group consisted of cases with intra-amniotic inflammation. Sub-analysis was performed for the groups in which IL-6 concentrations were measured. Adverse outcomes were evaluated with variables such as gestational age at delivery, interval from cerclage to delivery, chorioamnionitis and cumulative neonatal morbidity. Results: Elevated AF WBC was correlated with severe and extreme preterm delivery (p < 0.05). Decreased AF glucose was associated with histological chorioamnionitis and a decreased cerclage to delivery interval (p < 0.05). Elevated AF IL-6 correlated significantly with decreased gestational age at delivery (p < 0.012) and decreased cerclage to delivery interval (p < 0.001). Elevated IL-6 concentrations were associated with severe, extreme preterm delivery (p < 0.001) and neonatal death (p < 0.001). Conclusion: Elevated AF IL-6, elevated WBC and low AF glucose, in the absence of a positive AF culture, are significantly associated with adverse pregnancy outcomes in patients undergoing nonelective cerclage.     

Differential amniotic fluid cytokine profile in women with chorioamnionitis with and without funisitis

Objectives: To evaluate whether the amniotic fluid (AF) cytokine profile in women with chorioamnionitis may differentiate between those with and without funisitis.

Subjects and methods: Forty women at high risk of chorioamnionitis were studied. Gestational age at study was 26.94. Amniocentesis, universal and specific polymerase chain reaction, and microbiological cultures were performed. AF IL-1β, IL-2, IL-4, IL-6, IL 8, IL-10, IL-12, TNF-alpha, IFN-gamma, and MMP-8 were measured by multiplex assay. After delivery, the placenta and umbilical cord were studied histologically. Comparisons were made between three groups: controls, and chorioamnionitis with and without funisitis.

Results: In 25 cases, the histological findings were normal (61.5%). The remaining 15 composed of 9 cases of chorioamnionitis alone (9/40; 23.1%) and 6 cases of chorioamnionitis plus funisitis (6/40; 15.4%). All AF cytokine levels were significantly higher in the cases with chorioamnionitis in comparison to controls, except for IFN-gamma. The comparisons between the three groups showed significant differences between chorioamnionitis alone and chorioamnionitis plus funisitis in IL-1β, IL-6, IL-10, IL-12, IL-8, and TNF-alpha, with the levels being higher when funisitis was present. Logistic regression found a powerful predictive model for funisitis including the following cytokinesIL-4, IL-10, IL-12, and IL-8.

Conclusions: Measurements of AF interleukins 4, 10, 12, and 8 allow to identify cases with funisitisin women at high risk of chorioamnionitis.     

Maternal risk factors for preterm birth: a country-based population analysis

Objective

The aim of this study was to identify maternal risk factors for spontaneous preterm birth (PTB) compared to delivery at term, in order to recognize high risk women and to provide a global overview of the Italian situation.

Study design

A multicenter, observational and retrospective, cross-sectional study was designed. The study population comprised 7634 women recruited in 9 different University Maternity Hospitals in Italy. The main criteria for inclusion were: women having had vaginal preterm or term spontaneous delivery in each participating centre during the study period. The records related to deliveries occurring between April and December 2008. A multivariable logistic regression was employed to identify independent predictors of spontaneous preterm birth. Odds ratios (ORs) and 95% confidence intervals (95% CI) were reported with two-tailed probability (p) values. Statistical calculations were carried out using SAS version 9.1. A two-tailed p-value of 0.05 was used to define statistical significant results.

Results

A significant increased risk of PTB was found in women with BMI > 25 (OR = 1.662; 95% CI = 1.033–2.676; p-value = 0.0365) and in women employed in heavy work (OR = 1.947; 95% CI = 1.182–3.207; p-value = 0.0089). Moreover there was a significant association between PTB and previous reproductive history. In fact a history of previous abortion (OR = 1.954; 95% CI = 1.162–3.285; p-value = 0.0116) or previous cesarean section (OR = 2.904; 95% CI = 1.066–7.910; p-value = 0.0371) was positively correlated to the increased risk of PTB and an important statistically significant association was calculated between PTB and previous pre-term delivery (OR = 3.412; 95% CI = 1.342–8.676; p-value = 0.0099). All the other covariates examined as potential risk factors for PTB were not found to be statistically significantly related (p-value > 0.05).

Conclusions

The present study, applied to a substantial sample of Italian population, demonstrates that there are peculiar risk factors for spontaneous PTB in the Italian population examined. It shows an association between preterm delivery and certain maternal factors as: BMI, employment, previous abortions, previous PTBs and previous cesarean section.     

A point of care test for interleukin-6 in amniotic fluid in preterm prelabor rupture of membranes: a step toward the early treatment of acute intra-amniotic inflammation/infection

Objective: Preterm prelabor rupture of membranes (preterm PROM) accounts for 30–40% of spontaneous preterm deliveries and thus is a major contributor to perinatal morbidity and mortality. An amniotic fluid (AF) interleukin-6 (IL-6) concentration is a key cytokine for the identification of intra-amniotic inflammation, patients at risk of impending preterm delivery and adverse pregnancy complications. The conventional method to determine IL-6 concentrations in AF is an enzyme-linked immunosorbent assay (ELISA). However, this technique is not available in clinical settings, and the results may take several days. A lateral flow-based immunoassay, or point of care (POC) test, has been developed to address this issue. The objective of this study was to compare the performance of AF IL-6 determined by the POC test to that determined by ELISA for the identification of intra-amniotic inflammation in patients with preterm PROM.

Materials and methods: This retrospective cohort study includes 56 women with singleton pregnancies who presented with preterm PROM. Amniocentesis was performed at the time of diagnosis, and AF was analyzed using cultivation techniques for aerobic and anaerobic bacteria as well as genital mycoplasmas. AF Gram stain and AF white blood cell counts were determined. AF IL-6 concentrations were measured using both lateral flow-based immunoassay and ELISA. The primary outcome was intra-amniotic inflammation defined as AF ELISA IL-6?≥?2600?pg/ml. A previously determined cut-off of 745?pg/ml was used to define a positive POC test.

Results: (1) The POC test for AF IL-6 concentrations had 97% sensitivity and 96% specificity for the identification of intra-amniotic inflammation, as defined using ELISA among patients with preterm PROM and (2) the diagnostic performance of the POC test for IL-6 was strongly correlated to that of an ELISA test for the identification of intra-amniotic inflammation and was equivalent for the identification of acute inflammatory placental lesions and microbial invasion of the amniotic cavity (MIAC).

Conclusion: A POC AF IL-6 test can identify intra-amniotic inflammation in patients with preterm PROM. Results can be available within 20?min – this makes it possible to implement interventions designed to treat intra-amniotic inflammation and improve pregnancy outcomes.     

Maternal plasma interleukin-6, interleukin-1β and C-reactive protein as indicators of tocolysis failure and neonatal outcome after preterm delivery

Objective. To investigate whether maternal serum interleukin-6 (IL-6), interleukin-1β (IL-1β) and high sensitive C-reactive protein (CRP) could be used as markers of tocolysis failure and adverse neonatal outcome in pregnancies with preterm labor (PL).

Methods. Forty-seven maternal blood samples taken because of PL at admission and delivery were analyzed. Control samples were taken from 20 gravidas with normal pregnancies. Differences in interleukins and CRP levels with or without chorioamnionitis, connatal infection or periventricular leukomalacia (PVL) were analyzed. Cut-off values were estimated for prediction of tocolysis failure and adverse neonatal outcome.

Results. All three parameters were significantly higher in patients delivering prematurely than in patients delivering at term. All three parameters were significantly higher with than without histologic chorioamnionitis (p < 0.001), with than without connatal infection (p < 0.01), with than without PVL (p < 0.01 for IL-6 and IL-1β, p < 0.05 for CRP), and in pregnancies with preterm premature rupture of membranes (PPROM) delivered within 48 hours compared to those more prolonged (p < 0.01). Choosing 50.9 pg/mL of IL-6 and a CRP of 19.7 as cut-offs in maternal blood admission concentrations for neonatal PVL, resulted in sensitivity of 81% and specificity of 91% and sensitivity of 91% and specificity of 81%, respectively. At respective maternal blood admission cut-off levels of 27.8 pg/mL of IL-6 and 8.9 of CRP, both parameters were effective predictors of connatal infection.

Conclusions. Maternal blood IL-6 and CRP could become useful in predicting tocolysis failure and intrauterine treat for the fetus.     

A new anti-microbial combination prolongs the latency period,reduces acute histologic chorioamnionitis as well as funisitis,and improves neonatal outcomes in preterm PROM

Objective: Antibiotic administration is a standard practice in preterm premature rupture of membranes (PROM). Specific anti-microbial agents often include ampicillin and/or erythromycin. Anaerobes and genital mycoplasmas are frequently involved in preterm PROM, but are not adequately covered by antibiotics routinely used in clinical practice. Our objective was to compare outcomes of PROM treated with standard antibiotic administration versus a new combination more effective against these bacteria.

Study design: A retrospective study compared perinatal outcomes in 314 patients with PROM <34 weeks receiving anti-microbial regimen 1 (ampicillin and/or cephalosporins; n?=?195, 1993–2003) versus regimen 2 (ceftriaxone, clarithromycin and metronidazole; n?=?119, 2003–2012). Intra-amniotic infection/inflammation was assessed by positive amniotic fluid culture and/or an elevated amniotic fluid MMP-8 concentration (>23?ng/mL).

Results: (1) Patients treated with regimen 2 had a longer median antibiotic-to-delivery interval than those with regimen 1 [median (interquartile range) 23?d (10–51?d) versus 12?d (5–52?d), p?<?0.01]; (2) patients who received regimen 2 had lower rates of acute histologic chorioamnionitis (50.5% versus 66.7%, p?<?0.05) and funisitis (13.9% versus 42.9%, p?<?0.001) than those who had received regimen 1; (3) the rates of intra-ventricular hemorrhage (IVH) and cerebral palsy (CP) were significantly lower in patients allocated to regimen 2 than regimen 1 (IVH: 2.1% versus 19.0%, p?<?0.001 and CP: 0% versus 5.7%, p?<?0.05); and (4) subgroup analysis showed that regimen 2 improved perinatal outcomes in pregnancies with intra-amniotic infection/inflammation, but not in those without intra-amniotic infection/inflammation (after adjusting for gestational age and antenatal corticosteroid administration).

Conclusion: A new antibiotic combination consisting of ceftriaxone, clarithromycin, and metronidazole prolonged the latency period, reduced acute histologic chorioamnionitis/funisitis, and improved neonatal outcomes in patients with preterm PROM. These findings suggest that the combination of anti-microbial agents (ceftriaxone, clarithromycin, and metronidazole) may improve perinatal outcome in preterm PROM.     

Pentraxin 3 in amniotic fluid as a marker of intra-amniotic inflammation in women with preterm premature rupture of membranes

Objective

To determine whether amniotic fluid levels of pentraxin 3 (PTX3) are of value in the prenatal diagnosis of acute histological chorioamnionitis in preterm premature rupture of membranes (PPROM).

Methods

Forty pregnant women with PPROM between 24 and 36 weeks of pregnancy without (n = 21) and with (n = 19) histological chorioamnionitis (PPROM group) and 42 women between 16 and 20 weeks of pregnancy (midtrimester group) were included in the study. We compared amniotic fluid PTX3 levels in the PPROM group with versus without histological chorioamnionitis, and between the PPROM and the midtrimester groups using nonparametric tests (Mann-Whitney test), given the non-normal distribution of the analyte.

Results

Patients with histological chorioamnionitis had a significantly higher median amniotic fluid PTX3 concentration than patients without the histological signs of chorioamnionitis (3.69 ng/mL [0.51-106.8] versus 0.8 ng/mL [0.36-121.0]; P = 0.015). Patients in the PPROM group reached a significantly higher median amniotic fluid concentration of PTX3 compared with those in the midtrimester group (1.0 ng/mL [0.36-121.0] versus 0.67 ng/mL [0.4-2.8]; P = 0.007).

Conclusion

Histological chorioamnionitis is associated with a significant increase of amniotic fluid pentraxin 3 levels. Amniotic fluid pentraxin 3 appears to be a marker of intra-amniotic inflammation.     

The frequency and clinical significance of intra-amniotic inflammation in women with preterm uterine contractility but without cervical change: do the diagnostic criteria for preterm labor need to be changed?

Objective: The objective of this study was to determine the frequency and clinical significance of intra-amniotic inflammation in patients with preterm increased uterine contractility with intact membranes but without cervical change. Methods: Amniocentesis was performed in 132 patients with regular uterine contractions and intact membranes without cervical change. Amniotic fluid was cultured for bacteria and mycoplasmas and assayed for matrix metalloproteinase-8 (MMP-8). Intra-amniotic inflammation was defined as an elevated amniotic fluid MMP-8 concentration (>23?ng/mL). Results: (1) Intra-amniotic inflammation was present in 12.1% (16/132); (2) Culture-proven intra-amniotic infection was diagnosed in 3% (4/132) of patients without demonstrable cervical change on admission or during the period of observation; and (3) Patients with intra-amniotic inflammation had significantly higher rates of preterm delivery and adverse outcomes, and shorter amniocentesis-to-delivery intervals than those without intra-amniotic inflammation (P?<?0.05 for each). Adverse outcomes included chorioamnionitis, funisitis, and neonatal death. Conclusion: Intra-amniotic inflammation was present in 12% of patients with regular uterine contractions without cervical change, while culture-proven intra-amniotic infection was present in 3%. The presence of intra-amniotic inflammation was a significant risk factor for adverse neonatal outcomes. These observations question whether cervical changes should be required for the diagnosis of preterm labor, because patients without modifications in cervical status on admission or during a period of observation are at risk for adverse pregnancy outcomes.