Evaluation of amniotic fluid in preterm labor with intact membranes

Amniotic fluid was obtained from 35 pregnant women in preterm labor with intact membranes. Their gestational ages ranged from 24 to 34 weeks. Bacteria were detected in only 1 (3%) of the 35 amniotic fluid samples. The anaerobic culture grew Bacteroides corrodens and Fusobacterium nucleatum. The L/S ratio was greater than 4.0 in six patients (17%), 2.5-4.0 in two (6%) and less than 2.5 in 23 (66%); the quantity of fluid was inadequate for L/S analysis in four (11%). None of the 35 newborns developed evidence of infection in the neonatal period. Only two women (6%) were febrile postpartum, and none experienced a prolonged hospital stay. Seven (20%) of the infants developed respiratory distress syndrome. Five (14%) developed hyaline membrane disease, and two (6%) had transient tachypnea of the newborn. Intrauterine infection may play a lesser role in preterm labor with intact membranes than previously postulated. Amniocentesis may provide useful information for directing management by permitting one to assess fetal pulmonary maturity and the presence of meconium.     

Capnocytophaga in the amniotic fluid of a woman in preterm labor with intact membranes

Chorioamnionitis is thought to be uncommon with intact fetal membranes. A case is reported of a woman in preterm labor with intact membranes from whose amniotic fluid, placenta, and infant's gastric aspirate an unusual organism, Capnocytophaga, was identified. The findings are discussed.     

The incidence of positive amniotic fluid cultures in patients preterm labor with intact membranes

The possible relationship between intrauterine infection and preterm labor has received considerable attention in recent years. The purpose of this study was twofold: first, to determine the frequency of asymptomatic infection in patients who came to the hospital in preterm labor, and second, to determine the significance of a positive amniotic fluid culture in relation to latency period and likelihood of preterm delivery. Patients who came to the hospital in preterm labor with intact membranes between 20 and 35 weeks' gestation underwent transabdominal amniocentesis. Amniotic fluid was sent for Gram stain and culture. Patients received tocolytic therapy as clinically indicated. Of 127 patients cultured, seven (5.5%) had positive amniotic fluid cultures. These patients had a significantly decreased latency period from amniocentesis to delivery (4.4 days versus 28.6 days), and a significantly increased chance of being delivered of preterm infants (100% versus 52.5%), as compared with patients with negative cultures. The rate of positive Gram stain was 7 of 125 positive. However, there was no correlation between positive Gram stain and positive culture results. Similarly, positive Gram stain results were not associated with any difference in the latency period or rate of preterm delivery.     

Amniotic fluid glucose and cytokines values in the early diagnosis of amniotic infection in patients with preterm labor and intact membranes

Objective: Our goal was to compare sensitivity, specificity, and predictive values of glucose and cytokines [interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor (TNF)] in amniotic fluid (AF) to detect an AF-positive culture.

Methods: Amniocentesis was performed on 113 patients with preterm labour (PTL) and intact membranes. Fluid was cultured for aerobic and anaerobic bacteria, and for mycoplasmas. AF analysis included cytokines and glucose determinations.

Results: The prevalence of positive AF cultures was 11.5% (13/113). Anaerobic bacteria were isolated in 9 patients (69.2%). The glucose < 16 mg/dl and cytokines values; IL-1 >640 pg/ml, IL-6 >55,000 pg/ml, IL-8 >1,000 pg/ml, TNF >672 pg/ml, were significantly correlated (P< 0.01) with AF culture result. Glucose had a sensitivity of 69.2% and a specifity of 96% for the prediction of positive AF culture. The sensitivity and specifity of the cytokines ranged from 61.5–53.4% and 79.8–8.99%, respectively.

Conclusions: In the diagnosis of the AF-positive culture, glucose > 16 mg/dl is more sensitive than cytokines.     

Amniotic fluid matrix metalloproteinase-8 in preterm labor with intact membranes.

OBJECTIVE: Intra-amniotic inflammation is a major determinant of maternal and neonatal outcome in patients with preterm labor. Matrix metalloproteinase-8 is a sensitive marker of inflammation in body fluids. This study was conducted to examine the value of amniotic fluid matrix metalloproteinase-8 determinations in patients with preterm labor and intact membranes. STUDY DESIGN: Amniotic fluid was obtained by transabdominal amniocentesis from 371 patients with preterm labor. Fluid was cultured for aerobic and anaerobic bacteria and Mycoplasmas. Amniotic fluid analysis included Gram stain examination, white blood cell count, and matrix metalloproteinase-8 (enzyme-linked immunosorbent assay) determination. Nonparametric statistics were used for analysis. RESULTS: The rate of preterm delivery was 54% (200/371) and that of intra-amniotic infection was 9.2% (34/371). The median amniotic fluid matrix metalloproteinase-8 concentration was more than 50-fold higher in patients with intra-amniotic infection than in patients with no intra-amniotic infection (median, 605.6 ng/mL; range, 0.65-15,000 ng/mL vs median, 10.6 ng/mL; range, <0.06-16,600 ng/mL, respectively; P <.0001). The matrix metalloproteinase-8 amniotic fluid concentrations were significantly higher in patients who delivered preterm than in patients who delivered at term (median, 19.5 ng/mL; range, <0.06-16,600 ng/mL vs median, 2.1 ng/mL; range, <0.06-500 ng/mL, respectively; P <.001). After exclusion of patients with intra-amniotic infection, patients who delivered preterm had a significantly higher median amniotic fluid matrix metalloproteinase-8 than patients who delivered at term (P <.05). An amniotic fluid matrix metalloproteinase-8 level of >30 ng/mL was an independent predictor for the occurrence of neonatal morbidity (odds ratio, 3.4; 95% CI, 1.9-5.8; P <.01). CONCLUSION: Increased amniotic fluid matrix metalloproteinase-8 concentrations identify patients at risk for intra-amniotic infection, impending preterm delivery, and adverse neonatal outcome.     

Fusobacterium chorioamnionitis: report of two cases in preterm labor with intact amniotic membranes

Background: Preterm labor (PTL) in women with intact membranes may be caused by developing chorioamnionitis. Fusobacterium displays the ability to cause chorioamnionitis in the presence of intact amniotic membrane.Case: We report 2 patients with severe Fusobacterium chorioamnionitis which resulted in premature termination of pregnancy. Both patients presented with PTL and intact membranes. Neither initially appeared acutely ill. Despite the benign appearance, one woman rapidly deteriorated, requiring ventilation, pressor support, and surgical evacuation of the uterus.Conclusion: We feel that a Gram's Stain and proper collection of anaerobic cultures at the time of amniocentesis should be part of the evaluation of every patient with suspected chorioamnionitis.     

Fragmented forms of insulin-like growth factor binding protein-1 in amniotic fluid of patients with preterm labor and intact membranes

To determine the clinical significance of an increase in various fragmented forms of insulin-like growth factor binding protein-1 (IGFBP-1) in amniotic fluid (AF), a retrospective cohort study was conducted in 103 consecutive patients with preterm labor and intact membranes. Amniotic fluid samples were cultured for aerobic and anaerobic bacteria, and mycoplasmas, and then assayed for matrix metalloproteinase-8. Fragmented-to-intact IGFBP-1 ratios were evaluated by densitometric analysis of Western blot assays. Intact IGFBP-1 (30 kDa) and 21, 17, and 12 kDa fragments were detected in AF. Median ratios of fragmented-to-intact IGFBP-1 were higher in patients whose neonates had significant morbidity than in those whose neonates did not (P < .05), in patients spontaneously delivered within 2 and 7 days from amniocentesis than in those delivered after 2 and 7 days (P < .05), and in patients with intra-amniotic infection/inflammation than in those without (P < .001). Collectively, fragmented IGFBP-1 in AF may be indicators for adverse perinatal outcomes.     

Predictive model for spontaneous preterm labor among pregnant women with contractions and intact amniotic membranes

Purpose

To determine a predictive model for supporting decisions relating to the prognosis for women presenting with preterm labor and intact membranes.

Method

We conducted a prospective observational cohort study on 70 pregnant women at between 22 and 34?weeks of gestation. Transvaginal sonographic evaluation on the cervix was performed once on women who had completed a course of parenteral tocolysis. The sonographic parameters of cervical length measurement and presence of cervical glandular area were obtained. The outcome variable was occurrences of preterm delivery (<35?weeks). Using a univariate logistic regression model, the coefficients of each independent variable were first estimated. To construct the predictive model, multivariate logistic regression containing all the selected variables that might be related to preterm delivery was used as the starting point. Accuracy, sensitivity, specificity and predictive values were used to measure associations of predicted probabilities and to check the ability of the model to predict outcomes. The predictive analyses were based on logistic regression models, with calculation of odds ratios and 95?% confidence intervals.

Results

The incidence of preterm delivery was 32.80?% (23/70). After validation, the predictive model proposed showed accuracy of 87.88?%, sensitivity of 78.26?% and specificity of 93.02?%.

Conclusion

The model presented good accuracy with correspondence between predictions and observations, and has the capacity to become a useful tool for management of pregnant women with preterm labor and intact amniotic membranes.     

Intraamniotic infection in patients with intact membranes and preterm labor.

The purpose of this review was to determine the frequency of intraamniotic infection in women with preterm labor and intact membranes and to assess the need for amniocentesis in these patients. We reviewed reports in the English language literature from the past 10 years in which the frequency of intraamniotic infection was determined by transabdominal amniocentesis. The 16 studies reviewed demonstrated frequencies of positive cultures that varied from 0 to 61 per cent. This extreme variability seems to be the result of diverse patient populations, dissimilar microbiologic techniques, and different definitions of preterm labor. Advanced cervical dilation and poor response to tocolytic agents were two factors associated with a higher frequency of intraamniotic infection. We conclude that each institution must determine the frequency of intraamniotic infection associated with preterm labor in their patient population. In populations with a high frequency of infection, amniocentesis for microbiologic evaluation is recommended for management of preterm labor, especially in patients who have advanced cervical dilatation or who are unresponsive to tocolytic therapy.     

Vaginal indicators of amniotic fluid infection in preterm labor

OBJECTIVE: To determine whether vaginal interleukin-6, interleukin-8, neutrophils, bacterial vaginosis, and selected vaginal bacteria are predictors of amniotic fluid (AF) infection among women in preterm labor. METHODS: One hundred ninety-seven afebrile women in preterm labor with intact membranes had vaginal and AF samples collected for Gram stain, culture, and interleukin-8 and interleukin-6 determinations. Vaginal interleukin-6, interleukin-8, neutrophils, and vaginal flora were compared in women with positive and negative AF cultures. The negative AF culture group was subdivided according to AF interleukin-6 concentration. Logistic regression was used to examine the associations between vaginal cytokines and flora and AF infection or elevated AF interleukin-6. RESULTS: The vaginal interleukin-8 concentration and neutrophil count were significantly higher with both AF infection and elevated concentrations of AF interleukin-6 and interleukin-8. The vaginal interleukin-6 concentration was not associated with AF infection or high concentration of AF cytokines. Amniotic fluid infection was associated with bacterial vaginosis or intermediate vaginal flora by Gram stain, absence of hydrogen peroxide-producing Lactobacillus, and presence of vaginal Bacteroides ureolyticus and Fusobacterium. Vaginal interleukin-8 levels greater than 30 ng/mL had 80% sensitivity and a positive predictive value of 35%, and an abnormal vaginal Gram stain (more than five neutrophils per 400x field, bacterial vaginosis species, or intermediate flora) had 90% sensitivity and a positive predictive value of 27% to detect AF infection or elevated AF interleukin-6. CONCLUSION: A high vaginal interleukin-8 concentration, abnormal vaginal Gram stain, absent hydrogen peroxide-producing Lactobacillus, and anaerobic vaginal flora were strongly associated with AF infection among women in preterm labor.     

Maternal serum ferritin concentration in patients with preterm labor and intact membranes.

OBJECTIVE: To determine the relationship between maternal serum ferritin concentrations in the second trimester and the risk of preterm delivery (PTD). METHODS: A prospective observational study was conducted. Fifty consecutive women with singleton pregnancies, who were admitted to the Maternal Fetal Medicine Unit due to preterm labor in the second trimester, were included. Maternal serum samples for determination of ferritin concentrations were obtained. Multiple logistic regression analysis was performed to control for confounders. RESULTS: Out of fifty patients enrolled in the study, 38% (19/50) delivered prematurely. Eight women (16%) had maternal serum ferritin concentrations above 30 ng/ml in the second trimester. Among them, 75% (n = 6) subsequently presented with preterm delivery (odds ratio (OR) = 6.7 with 95% confidence interval (CI) 1.1-56.2, p = 0.04). Only two patients with increased maternal ferritin concentrations delivered at term. However, 13 patients with second trimester ferritin concentrations below 30 ng/ml had preterm delivery. No significant differences in mean maternal ferritin concentrations were found between patients who delivered preterm and those that delivered at term, 31.9 +/- 50.6 vs. 13.6 +/- 15.2, respectively (p = 0.064). Using a multivariable analysis, controlling for anemia, leucocytosis and maternal age, increased serum ferritin concentrations were found to be an independent risk factor for PTD (OR = 8.6; 95% CI 1.4-52.5; p < 0.019). No significant correlation was found between serum ferritin concentrations and gestational age at birth (Pearson correlation coefficient r = -0.093; p = 0.522). CONCLUSIONS: Maternal ferritin concentrations above 30 ng/ml in the second trimester can serve as a marker for preterm delivery. However, since no correlation was found between serum ferritin concentrations and gestational age at birth, the routine use of serum ferritin as a marker for preterm delivery warrants further investigation.     

Clinical significance of intra-amniotic inflammation in patients with preterm labor and intact membranes.

OBJECTIVE: The purpose of this study was to determine the frequency and clinical significance of intraamniotic inflammation in patients with preterm labor and intact membranes. STUDY DESIGN: Amniocentesis was performed in 206 patients with preterm labor and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria and mycoplasmas. The diagnosis of intraamniotic inflammation was made in patients with a negative amniotic fluid culture on the basis of amniotic fluid concentrations of interleukin-6 (>2.6 ng/mL, derived from receiver operating characteristic curve analysis). Statistical analysis was conducted with contingency tables and survival techniques. RESULTS: Intra-amniotic inflammation (negative amniotic fluid culture but elevated amniotic fluid interleukin-6) was more common than intra-amniotic infection (positive amniotic fluid culture regardless of amniotic fluid interleukin-6 concentration; 21% [44/206 women] vs 10% [21/206 women]; P <.001). The amniocentesisto-delivery interval was significantly shorter in patients with intra-amniotic inflammation than in patients with a negative culture and without an inflammation (median, 20 hours [range, 0.1-2328 hours] vs median, 701 hours [range, 0.1-3252 hours], respectively; P <.0001). Spontaneous preterm delivery of <37 weeks was more frequent in patients with intra-amniotic inflammation than in those with a negative culture and without inflammation (98% vs 35%; P <.001). Patients with intra-amniotic inflammation had a significantly higher rate of adverse outcome than patients with a negative culture and without intra-amniotic inflammation. Adverse outcomes included clinical and histologic chorioamnionitis, funisitis, early preterm birth, and significant neonatal morbidity. There were no significant differences in the rate of adverse outcomes between patients with a negative culture but with intra-amniotic inflammation and patients with intra-amniotic infection (positive culture regardless of amniotic fluid interleukin-6 concentration). CONCLUSION: Intra-amniotic inflammation/infection complicates one third of the patients with preterm labor (32%; 65/206 women), and its presence is a risk factor for adverse outcome. The outcome of patients with microbiologically proven intra-amniotic infection is similar to that of patients with intra-amniotic inflammation and a negative amniotic fluid culture. We propose that the treatment of patients in preterm labor be based on the operational diagnosis of intra-amniotic inflammation rather than the diagnosis of intra-amniotic infection because the latter diagnosis cannot be undertaken rapidly.     

Validity of amniotic fluid index in preterm rupture of membranes

BACKGROUND: Preterm premature rupture of membranes (pPROM) complicates up to one-third of preterm deliveries. We studied the Amniotic Fluid Index (AFI) in order to ascertain its validity as a predictive variable of maternal-fetal outcome in pregnancies complicated by pPROM. STUDY DESIGN: One hundred and fourteen pregnant women with gestational age between 24 and 34 weeks' gestation at the time of pPROM. Patients were categorized into two groups on the basis of AFI value (AFI <5 cm=63 or AFI >or=5 cm=51) performed at the time of admission. RESULTS: AFI numeric values were significantly related to the following maternal-neonatal variables: high maternal body temperature (P7 at 5 min (P相似文献   

Maternal plasma and amniotic fluid dehydroepiandrosterone-sulfate concentrations in preterm labor and delivery

The purpose of this study was to determine whether preterm parturition is associated with changes in maternal plasma and amniotic fluid dehydroepiandrosterone-sulfate concentrations. A cross sectional study was constructed according to the gestational age at admission and response to tocolysis. Group 1 consisted of women admitted with preterm labor and intact membranes between 28 and 31 weeks and 6 days gestational age (n=40). Group 2 included 40 patients with preterm labor between 32 and 36 weeks gestational age. Both groups were classified into two subgroups: preterm delivery within seven days of admission and term delivery. Commercially available immunoassay kits validated for amniotic fluid analysis of DHEA-S, were used to measure maternal plasma and amniotic fluid DHEA-S concentrations. Maternal plasma DHEA-S concentrations were significantly higher in women with preterm labor who delivered preterm than in those who delivered at term. (Group 1: median 800 ng/ml [range 100–1100] vs. median 200 ng/ml [70–800],P<0.001; Group 2: median 850 ng/ml [300–1700] vs. median 300 ng/ml [90–1100],P<0.001). In contrast, no significant differences were detected in amniotic fluid DHEA-S concentrations. Our data suggest that the rise in maternal plasma DHEA-S concentrations observed in patients with preterm labor may be related to the effects of stress during labor.