The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI) was associated with subsequent ruptured membranes in women with preterm labor and intact membranes who had a clinically indicated amniocentesis. This retrospective cohort study included 237 consecutive women with preterm labor (20-34.6 weeks) who underwent amniocentesis. The clinical and laboratory parameters evaluated included demographic variables, gestational age, C-reactive protein (CRP) and amniotic fluid (AF) white blood cell, interleukin-6 (IL-6) and culture results. IAI was defined as a positive AF culture and/or an elevated AF IL-6 level (>2.6 ng/mL). The primary outcome was ruptured membranes in the absence of active labor occurring within 48 hours of amniocentesis. Preterm premature rupture of membranes subsequently developed in 10 (4.2%) women within 48 hr of amniocentesis. Multivariate analysis demonstrated that only IAI was independently associated with the ruptured membranes occurring within 48 hr of amniocentesis. In the predictive model based on variables assessed before amniocentesis, only CRP level was retained. IAI is an independent risk factor for subsequent ruptured membranes after clinically indicated amniocentesis in preterm labor. Prior to amniocentesis, measurement of serum CRP level can provide a risk assessment for the subsequent development of ruptured membranes after the procedure.
Adult ; Amniocentesis/*adverse effects ; Amnion/physiopathology ; Amniotic Fluid/cytology/metabolism/microbiology ; Bacterial Infections/*etiology/microbiology ; C-Reactive Protein/analysis ; Cohort Studies ; Demography ; Female ; Gestational Age ; Humans ; Inflammation/*etiology ; Interleukin-6/metabolism ; Leukocytes/cytology ; Multivariate Analysis ; Mycoplasma/isolation & purification ; Obstetric Labor, Premature/*etiology ; Pregnancy ; ROC Curve ; Retrospective Studies ; Risk Factors ; Ureaplasma urealyticum/isolation & purification

The aims of this study were to determine whether sonographically measured cervical length is of value in the identification of microbial invasion of the amniotic cavity in women with preterm premature rupture of membranes (PPROM) and to compare its performance with maternal blood C-reactive protein (CRP), white blood cell count (WBC), and amniotic fluid (AF) WBC. This prospective observational study enrolled 50 singleton pregnancies with PPROM. Transvaginal ultrasound for measurement of cervical length was performed and maternal blood was collected for the determination of CRP and WBC at the time of amniocentesis. AF obtained by amniocentesis was cultured and WBC determined. The prevalence of a positive amniotic fluid culture was 26% (13/50). Patients with positive amniotic fluid cultures had a significantly shorter median cervical length and higher median CRP, WBC, and AF WBC than did those with negative cultures. Multiple logistic regression indicated that only cervical length had a significant relationship with the log odds of a positive AF culture. Transvaginal sonographic measurement of cervical length is valuable in the identification of microbial invasion of amniotic cavity in women with PPROM. Cervical length performs better than AF WBC, maternal blood CRP, and WBC in the identification of a positive amniotic fluid culture.
Adult ; Amniocentesis/methods ; Amniotic Fluid/*microbiology ; Bacterial Infections/*complications ; C-Reactive Protein/metabolism ; Cervix Uteri/*ultrasonography ; Female ; Fetal Membranes, Premature Rupture/etiology/*ultrasonography ; Gestational Age ; Humans ; Leukocyte Count ; Logistic Models ; Maternal Age ; Pregnancy ; Pregnancy Complications, Infectious/blood/etiology/ultrasonography ; Prospective Studies ; Risk Factors ; Ultrasonography/methods

In the present study, the relationship among iron-availability, antibacterial activity, role of meconium as an iron source and the activity of bacterial iron-uptake system (IUS) for bacterial growth in amniotic fluid (AF) were investigated. Staphylococcus aureus ATCC 6538 and its streptonigrin-resistant (SR) mutant with defective IUS were used as the test strains. The growth of S. aureus in AF was stimulated dosedependently by addition of meconium. Bacterial growth stimulated by meconium was re-inhibited dose-dependently by addition of iron-chelator, dipyridyl and apotransferrin. Iron concentration was correlated with the meconium content in AF (r(2)= 0.989, p=0.001). High-affinity IUS of S. aureus was expressed only in AF but not in AF with meconium. The growth of SR strain was more retarded than that of the parental strain in the iron-deficient brain heart infusion (ID-BHI), clear AF and AF containing apotransferrin. The retarded growth of both strains in the ID-BHI and AF was recovered by addition of holotransferrin, hemoglobin and FeCl3. Taken together, the antibacterial activity of AF is closely related with low iron-availability. Bacterial growth in AF considerably depends on the activity of bacterial IUS. Meconium acts as one of the exogenous iron-sources and thus can stimulate bacterial growth in AF.
Amniotic Fluid/*microbiology ; Antibiotics, Antineoplastic/pharmacology ; Chelating Agents/pharmacology ; Dose-Response Relationship, Drug ; Female ; Ferric Compounds/pharmacology ; Human ; Iron/*metabolism ; Ligands ; Meconium/metabolism ; Mutation ; Pregnancy ; Pregnancy Trimester, Third ; Protein Binding ; Staphylococcus aureus/metabolism ; Streptonigrin/pharmacology ; Support, Non-U.S. Gov't ; Time Factors

PURPOSE: To develop a model based on non-invasive clinical and ultrasonographic parameters for predicting the likelihood of subsequent histologic chorioamnionitis in women with preterm premature rupture of membranes (PPROM) and to determine whether the inclusion of invasive test results improves the predictive value of the model. MATERIALS AND METHODS: This retrospective cohort study included 146 consecutive women presenting with PPROM (20-33 weeks). Transvaginal ultrasonographic assessment of cervical length was performed. Maternal serum C-reactive protein (CRP) levels and white blood cell (WBC) counts were measured after amniocentesis. Amniotic fluid (AF) obtained by amniocentesis was cultured, and interleukin-6 (IL-6) levels and WBC counts were determined. The primary outcome measure was histologic chorioamnionitis. RESULTS: Risk scores based on serum CRP concentrations and gestational age (model 1) were calculated for each patient. The model was shown to have adequate goodness of fit and an area under the receiver operating characteristic curve (AUC) of 0.742. When including AF test results (e.g., AF IL-6 levels) in model 1, serum CRP concentrations were found to be insignificant, and thus, were excluded from model 2, comprising AF IL-6 levels and gestational age. No significant difference in AUC was found between models 1 and 2. CONCLUSION: For women with PPROM, the newly developed model incorporating non-invasive parameters (serum CRP and gestational age) was moderately predictive of histologic chorioamnionitis. The inclusion of invasive test results added no predictive information to the model in this setting.
Adult ; *Amniocentesis ; Amniotic Fluid/*cytology/microbiology ; C-Reactive Protein/*metabolism ; Chorioamnionitis/blood/*diagnosis/metabolism ; Cohort Studies ; Female ; Fetal Membranes, Premature Rupture/*blood ; *Gestational Age ; Humans ; Infant, Newborn ; Interleukin-6/blood ; Leukocyte Count ; Predictive Value of Tests ; Pregnancy ; ROC Curve ; Retrospective Studies ; Sensitivity and Specificity