Factors associated with latency period in preterm prelabor rupture of membranes

Objective: To determine the factors associated with prolonged latency periods in preterm prelabor rupture of membrane (PPROM).

Methods: This retrospective study analyzed data from singleton pregnant women with gestational age between 28 and 34 weeks suffering from PROM. Multivariate regression analysis was used to evaluate the association between the factors and latency period?≥?2 and?≥?7 days.

Results: A total of 231 cases of PPROM were included. Prolong latency period?≥2 and 7 days were achieved in 141 (61%) and 54 (23.4%) cases. Higher gestational age at PPROM and cervical dilatation?>2?cm were associated with a shorter latency period <2 days. Multiparity and presence of uterine contraction at admission were associated with a shorter latency period <7 days. Prophylactic antibiotics [odds ratio (ORs) 6.69, 95% confidence interval (CI) 3.0–14.89], and tocolysis (ORs 2.74, 95%CI 1.25–6.02) were factors associated with latency period?≥?2 days. Only prophylactic antibiotics (ORs 7.7, 95%CI 2.54–23.34) was a factor associated with latency period?≥7 days.

Conclusions: Prophylactic antibiotics and tocolysis are two major factors associated with latency period?≥2 days in PPROM, where prophylactic antibiotics is the main factor associated with latency period?≥7 days in PPROM.     

Histological chorioamnionitis in preterm prelabor rupture of the membranes is associated with increased expression of galectin-3 by amniotic epithelium

Purpose: Gal-3, which can regulate immune responses upon infection and inflammation, was not studied so far in intrauterine infection leading to preterm prelabor rupture of the membranes (PPROM), although gal-1 was reported to be implicated in the process. Gal-3 mRNA and protein expression in amnion and its changes during histological chorioamnionitis were studied here.

Materials and methods: Fetal membranes were obtained from women with PPROM with (n?=15) and without histological chorioamnionitis (n?=15) during second and third trimester. Immunohistochemical reactivity was evaluated semiquantitatively and analyzed using t-test. Galectin profile of amniotic epithelia was determined by polymerase chain reaction (PCR) and change assessed in gal-3 in PPROM with (n?=5) or without histological chorioamnionitis (n?=5) by real-time PCR.

Results: Human amniotic epithelium was found to express gal-1, gal-3, gal-7 and gal-8 mRNA. Gal-3 mRNA and protein is increased in fetal membranes and in the amniotic epithelium in patients with chorionamnionitis.

Conclusion: Histological chorioamnionitis is associated with increased gal-3 expression and strong immunoreactivity of the amnion. Gal-3 may participate in the regulation of the inflammatory responses to chorioamniotic infection and/or direct interaction with pathogens.     

A systematic review of intentional delivery in women with preterm prelabor rupture of membranes

Objective.?To evaluate the effect of intentional delivery versus expectant management in women with preterm prelabor rupture of membranes (PPROM).

Methods.?We searched electronic databases and trials registries, contacted experts, and checked reference lists of relevant studies. Studies were included if they were randomized controlled trials comparing intentional delivery versus expectant management after PPROM, the gestational age of participants was between 30 and 36 weeks, and the study reported one of several pre-determined outcomes.

Results.?Four studies were included in the meta-analysis. No difference was found between intentional delivery and expectant management in neonatal intensive care unit (NICU) length of stay (LOS) (weighted mean difference (WMD) ?0.81 day, 95% confidence interval (CI) ?1.66, 0.04), respiratory distress syndrome (risk difference (RD) ?0.01, 95% CI ?0.07, 0.06), and confirmed neonatal sepsis (RD ?0.01, 95% CI ?0.05, 0.04). One study found a significantly lower incidence of suspected neonatal sepsis among the intentional delivery group (RD ?0.31, 95% CI ?0.50, ?0.12; number needed to treat (NNT) 3, 95% CI 2, 8). Maternal LOS was significantly shorter for the intentional delivery group (WMD ?1.39 day, 95% CI ?2.03, ?0.75). There was a significant difference in the incidence of clinical chorioamnionitis favoring intentional delivery (RD ?0.16, 95% CI ?0.23, ?0.10; NNT 6, 95% CI 5, 11). There was no significant difference in the incidence of other maternal outcomes, including cesarean section (RD 0.05, 95% CI ?0.01, 0.11).

Conclusions.?Intentional delivery may be favorable to expectant management for some maternal outcomes (chorioamnionitis and LOS). There is insufficient evidence to suggest that either strategy is beneficial or harmful for the baby. Large multicenter trials with primary neonatal outcomes are required to assess whether intentional delivery is associated with less neonatal morbidity.     

Procalcitonin for prediction of chorioamnionitis in preterm premature rupture of membranes*

Objective: To assess serum procalcitonin (PCT), a marker of monocyte activity, in predicting chorioamnionitis in preterm premature rupture of membranes (PPROM).

Methods: Prospective cohort study in singleton gestation patients with PPROM between 2 2?+?0 to 3 3?+?6 weeks gestation. Two blood samples were taken – admission and delivery or diagnosis of clinical chorioamnionitis. Maternal serum PCT?>?0.1?ng/mL was considered positive. Patients were divided into four groups: clinical evidence of chorioamnionitis confirmed by placental pathology (group C?+?P); pathological evidence of chorioamnionitis without clinical signs (group P); clinical signs only (group C); and patients without clinical or pathological findings (group N). Groups were compared to gestational age matched controls.

Results: Forty eight patients recruited, with 28 eligible for analysis: 10 in C?+?P group, 10 P group, 3 C group, and 5?N group. None of the control or PPROM patients had positive PCT on admission. At delivery, 3 of 10 group C?+?P and 4 of 10 group P had positive PCT. Maternal serum PCT sensitivity was 50% and specificity 55.6% for diagnosis of pathological chorioamnionitis.

Conclusions: Maternal serum PCT is not detectable in PPROM patients at admission or in uncomplicated pregnant controls and is a poor predictor for clinical or pathological chorioamnionitis.     

The fetal inflammatory response in subgroups of women with preterm prelabor rupture of the membranes

Abstract

Objective: To evaluate the influence of microbial invasion of the amniotic cavity (MIAC) and histological chorioamnionitis (HCA) on the intensity of the fetal inflammatory response and the occurrence of fetal inflammatory response syndrome (FIRS) in preterm prelabor rupture of membranes (PPROM).

Methods: One hundred and forty-nine women with singleton pregnancies complicated by PPROM between the gestational ages 24?+?0 and 36?+?6 weeks were included in the study. Blood samples were obtained by venipuncture from the umbilical cord after the delivery of the newborn. The umbilical cord blood interleukin (IL)-6 levels were evaluated using ELISA kits. The fetal inflammatory response was determined by IL-6 levels, and FIRS was defined as an umbilical cord blood IL-6 >11?pg/mL.

Result: IL-6 levels and the occurrence of FIRS were higher in women complicated with both MIAC and HCA (median IL-6 35.5?pg/mL, FIRS in 68%) than in women with HCA alone (median IL-6 5.8?pg/mL, FIRS in 36%), MIAC alone (median IL-6 2.8?pg/mL, FIRS in 17%) or women without MIAC or HCA (median IL-6 4.3?pg/mL, FIRS in 29%). There were no differences in IL-6 levels or rates of FIRS among women with MIAC alone or HCA alone and women without both MIAC and HCA.

Conclusion: A higher fetal inflammatory response mediated by umbilical cord blood IL-6 was identified when both MIAC and HCA were detected in pregnancies complicated by PPROM.     

Amniotic fluid fetal hemoglobin in normal pregnancies and pregnancies complicated with preterm labor or prelabor rupture of membranes

Objective. Hemoglobin and its catabolic products have been associated with amniotic fluid (AF) discoloration and intra-amniotic infection/inflammation (IAI). However, the origin of AF hemoglobin (maternal or fetal) has not been determined. The aims of this study were to determine if fetal hemoglobin can be detected in AF obtained from normal pregnancies, and whether there is an association between AF fetal hemoglobin concentrations and gestational age, spontaneous labor (term and preterm), preterm prelabor rupture of membranes (PPROM) and IAI.

Study design. This cross-sectional study included pregnant women in the following groups: (1) mid-trimester (n = 60); (2) term not in labor (n = 21); (3) term in labor (n = 47); (4) spontaneous preterm labor with intact membranes (PTL) without IAI who delivered at term (n = 89); (5) PTL without IAI who delivered preterm (n = 74); (6) PTL with IAI (n = 78); (7) PPROM with (n = 48) and (8) without IAI (n = 48). AF fetal hemoglobin concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

Results. (1) Fetal hemoglobin was detected in 80.4% of all AF samples; (2) women at term not in labor had a higher median AF fetal hemoglobin concentration than those at mid-trimester (p = 0.008); (3) labor at term was not associated with a significant difference in the median AF fetal hemoglobin concentration; (4) the median AF fetal hemoglobin concentration was not significantly different among the three PTL groups or between the PPROM groups; (5) women with PTL and IAI had a lower AF fetal hemoglobin percentage of the total hemoglobin than those without IAI who delivered preterm (p = 0.03) or at term (p < 0.001); (6) The median AF fetal hemoglobin concentration was higher in pregnancies complicated with PTL or PPROM than in women at term (p < 0.001 for all comparison).

Conclusions. (1) The concentration of immunoreactive AF fetal hemoglobin increases with gestational age; (2) the median AF fetal hemoglobin concentration is higher in pregnancies complicated with PTL or PPROM than in term pregnancies; (3) among women with PTL or PPROM, the AF fetal hemoglobin concentrations were not associated with IAI; (4) however, women with PTL and IAI had a lower percentage of AF fetal hemoglobin of the total hemoglobin than those without IAI, suggesting different mechanisms of disease.     

Treatment options for bacterial vaginosis in patients at high risk of preterm labor and premature rupture of membranes

AIM: To estimate the efficacy of different therapeutic modalities on proven cases of bacterial vaginosis (BV) in patients at high risk of preterm labor and premature rupture of membranes. METHODS: This was a longitudinal prospective comparative study set in the antenatal outpatient clinic of the department of Obstetrics and Gynecology, Faculty of Medicine, Assiut University, Assiut, Egypt. Four hundred and sixty-eight patients with a clinical picture of threatened preterm labor or at high risk of premature rupture of membranes in the third trimester were screened for BV. Positive BV was diagnosed in 156 patients. They were randomly classified into four equal groups according to the line of medical treatment. The treatments were: (i) oral metronidazole, (ii) clindamycin vaginal cream, (iii) oral clindamycin, or (iv) metronidazole vaginal suppositories. The effects of medical treatment on Amsel's criteria as well as maternal and fetal outcomes were measured. RESULTS: Based on Amsel's criteria, 156 patients (33.3%) were diagnosed with BV. There was a significant disappearance of vaginal discharge, with decreased percentages of pH > 4.5, positive amine test, and clue cells after treatment of BV in the four groups without any statistically significant difference between them. There were variable effects of the different treatments on increasing birthweight values, admission to neonatal intensive care units, and prolongation of the gestational age. Some maternal adverse effects have been recorded. There were significant improvements of the outcomes for oral metronidazole and clindamycin compared with outcomes for intravaginal metronidazole and clindamycin. CONCLUSIONS: Metronidazole and clindamycin achieve nearly equivalent cure rates when administered orally or vaginally in patients at high risk of preterm labor and premature rupture of membranes. Oral metronidazole is considered the drug of choice in treating BV due its high cure rate, better outcomes, and low cost.     

Residual amniotic fluid volume predicts the sealing of preterm prelabor rupture of fetal membranes in the pre- and periviable period

ObjectivePreterm prelabor rupture of fetal membranes (pPROM) is a leading cause of preterm birth. When pPROM occurs around the pre- and periviable period, the perinatal outcome is unfavorable. However, there have been a few cases in which the leakage of amniotic fluid ceases and the ruptured fetal membranes are spontaneously sealed.Materials and methodsThe prognosis of 38 cases of pPROM at less than 27 weeks of gestation in Kyoto University Hospital were studied. The clinical factors related to the sealing of fetal membranes were investigated.ResultsSpontaneous sealing was confirmed in five patients (13%), and sealing occurred within 14 days of pPROM. Women in the no sealing group delivered at 26.3 ± 0.5 weeks of gestation, whereas women in the sealing group delivered at term at 38.8 ± 0.4 weeks (p < 0.0001). The maximum vertical pocket (MVP) of amniotic fluid at the time of pPROM diagnosis was 2.2 ± 0.3 cm in the no sealing group and 3.8 ± 0.5 cm in the sealing group (p = 0.043). All cases of sealing occurred when the MVP at diagnosis was more than 2 cm, and there were no cases of sealing if the MVP at diagnosis was less than 2 cm. In addition, the value of C-reactive protein at ROM was less than 0.4 mg/dL in all cases in the sealing group.ConclusionThe residual volume of sterile amniotic fluid at the onset of pPROM may predict the possibility of fetal membrane sealing.     

Continuous fetal heart rate monitoring in patients with preterm premature rupture of membranes undergoing expectant management

Objective.?Continuous fetal heart rate (FHR) monitoring is considered by some as necessary to the expectant management of patients with preterm premature rupture of membranes (PPROM). No data exist to support this premise, and liability may be incurred if such an order cannot be practically carried out. The purpose of our study is to evaluate the performance of prolonged FHR monitoring in terms of the completeness of recorded tracings.

Methods.?A retrospective cohort study was performed between 2004 and 2006 in a tertiary care hospital on patients being expectantly managed with PPROM at 24–34 weeks of gestation. Forty-seven singleton gravidas with a physician order of continuous external FHR monitoring were included. Exclusion criteria were evidence of labour, chorioamnionitis or FHR abnormalities that prompted delivery. FHR tracings during the prolonged monitoring period were reviewed.

Results.?The study cohort was monitored for a duration of 321–2272 min (mean 970 min). In total, 28.3% (95% confidence interval 23.8–33%) of the tracing did not show a legible recording. Gestational age is negatively correlated with the proportion of absent tracing, whereas body mass index is positively correlated. There is no significant difference in the absent signal proportion between the first half of the monitoring period and the second half or between day and night.

Conclusions.?In patients with PPROM being expectantly managed, a significant proportion (28.3%) of the FHR tracing was not recorded as ordered. This suggests that ‘continuous’ prolonged external fetal monitoring may not be practically feasible and alternative monitoring approaches should be considered.     

Community-based antenatal home care programme for the management of preterm premature rupture of membranes

Objective: to determine whether a structured community-based antenatal home care programme for selected patients with spontaneous preterm premature rupture of membranes (SPPROM), providing daily nursing monitoring, patient education, and supported by medical supervisors, is an acceptable alternative to total in-hospital care.Methods: in a retrospective cohort-control study, we compared the profile and outcomes of patients with SPPROM managed in the antenatal home care programme (AHCP) between 1992 and 1996 to a historic control managed by total in-hospital care (HOSP) between 1987 and 1991. Outcome measures included length of latency period, incidence of chorioamnionitis, gestational age at delivery, birth weight, incidence of admission to the neonatal intensive care unit (NICU), and neonatal morbidity. We used regression analyses to determine predictors of selected outcomes.Results: the two cohorts (AHCP, n = 59 and HOSP, n = 54) were not significantly different in gestational age at SPPROM, antenatal antibiotic use, or rates of Group B Streptococcus colonization. Use of corticosteroids was significantly more frequent in the AHCP cohort (44% vs. 22%, p = 0.02). AHCP patients had longer latency duration to delivery (24.6 vs. 12 days, p<0.001), less chorioamnionitis (17% vs. 35%, p = 0.03), more advanced gestational age at delivery (33 vs. 31 weeks, p<0.001), and their newborns had fewer admissions to the neonatal intensive care unit (45% vs. 75%, p = 0.001). Using regression analyses, site of care and gestational age at SPPROM were significant predictors of gestational age at delivery and chorioamnionitis, adjusting for antibiotic use, steroid use, and Group B Streptococcus status.Conclusion: Management of selected patients with SPPROM by a structured community-based antenatal home care programme, rather than total in-hospital care, is feasible and may be associated with improved maternal and neonatal outcomes. Further evaluation by a randomized trial is warranted.     

Distinct molecular events suggest different pathways for preterm labor and premature rupture of membranes

OBJECTIVE: On a clinical level, the etiologies associated with premature rupture of the membranes and preterm labor are virtually identical, though these conditions end in distinctly different events. This study was designed to determine differences between preterm labor and preterm premature rupture of membranes by using molecular markers of extracellular matrix degradation and apoptosis. STUDY DESIGN: Amniochorion and amniotic fluid samples were collected from gestational age-matched groups of women undergoing cesarean delivery before term. Samples were collected from 2 groups of women, women with premature rupture of membranes and women with preterm labor with no rupture of membranes. Changes in the expression pattern of messenger ribonucleic acid for matrix metalloproteinases (MMP), tissue inhibitor of metalloproteinases (TIMP), and pro-apoptotic (p53 and Bax) and anti-apoptotic (Bcl-2) proteins were identified by quantitative polymerase chain reaction. Enzyme-linked immunosorbent assay was used to determine the levels of these proteins in the amniotic fluid. Multiplex polymerase chain reaction was performed to study the expression of Fas-Fas ligand-associated pro-apoptotic genes. Unpaired nonparametric, 2-tailed Mann-Whitney U test was used to determine statistical significance of quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (P <.05 was considered significant). RESULTS: Quantitative polymerase chain reaction results demonstrated an increased mRNA expression for MMP2, MMP9, and MT1-MMP and a decreased expression for TIMP2 in prematurely ruptured membranes compared with preterm labor membranes. Enzyme-linked immunosorbent assay documented increases in the amniotic fluid concentrations of immunoreactive and bioactive MMP2 and MMP9 and immunoreactive MMP3 and a decreased TIMP2 concentration in fluids obtained from the premature rupture of membranes group compared with the preterm labor group. The pro-apoptotic genes p53 and bax were up-regulated in premature rupture of membranes when compared with preterm labor. Anti-apoptotic gene (Bcl-2 ) expression was increased in preterm labor membranes compared with prematurely ruptured membranes. Interleukin-18 (a pro-apoptotic cytokine) was increased in the amniotic fluid during premature rupture of membranes compared with preterm labor. Prematurely ruptured membranes also demonstrated fragmented deoxyribonucleic acid and expression of Fas and caspase 8 (apoptosis initiator), which were all absent in preterm labor membranes. CONCLUSIONS: We have begun to delineate 2 divergent molecular pathways for premature rupture of membranes and preterm labor. Most likely, this is the beginning of the identification of differences that will become evident with the use of molecular biology.     

Comparative study of induction of labor in nulliparous women with premature rupture of membranes at term compared to those with intact membranes: duration of labor and mode of delivery

AIM: To evaluate the effect of premature rupture of membranes (PROM) at term on the duration of labor and mode of delivery in comparison with intact membranes in nulliparous women with an unfavorable cervix whose labor was induced. METHODS: This retrospective cohort study included all term nulliparous women with an unfavorable cervix requiring labor induction over a 2-year period. Prostaglandin E(2) (dinoprostone) and oxytocin were used for labor induction. Criteria for enrolment included (i) singleton pregnancy; (ii) term nulliparous women; or (iii) Bishop score below 6. Statistics were analyzed with Student's t-test, chi(2)-test, Fisher's exact test, and multiple logistic regression. RESULTS: Our study subjects were 82 women whose labor was induced for PROM and 219 women with intact membranes whose labor was induced for social or fetal reasons. The mean durations of active phase of labor were not significantly different between women with PROM and those with intact membranes. However, the women with PROM had a significantly longer mean duration of second stage and a higher rate of cesarean delivery for failure to progress than those with intact membranes. Multiple logistic regression demonstrated that only PROM and fetal macrosomia were significantly associated with an increased risk of cesarean delivery for failure to progress after other confounding variables were adjusted. CONCLUSIONS: Labor induction for PROM at term in nulliparous women with an unfavorable cervix is associated with longer duration of the second stage and a higher risk of cesarean delivery for failure to progress in comparison to those with intact membranes.     

Lack of relationship between histologic chorioamnionitis and duration of the latency period in preterm rupture of membranes

It is often believed that the frequency of clinical chorioamnionitis in preterm premature rupture of membranes (PROM) increases with the duration of the interval between membrane rupture and delivery. We tested the hypothesis that the prevalence of histologic evidence of intrauterine infection increases proportionally to the duration of the latency period. A total of 191 consecutive placentas of singleton, nonanomalous, liveborn infants delivered at > 32 weeks' gestation with PROM were examined prospectively. Demographic, obstetric, histopathologic, and neonatal information was obtained. Histopathologic evidence of acute inflammation in choriodecidua, amnion, umbilical cord, and chorionic plate was recorded and scored. The prevalence and severity of pathological evidence of intrauterine infection was correlated with the interval between membrane rupture and delivery. Maternal and neonatal outcomes were assessed in six groups defined by different intervals between membrane rupture and delivery. Statistical analysis utilized regression, Fisher's exact test, Chi-square, and one-way analysis of variance after log transformation where applicable. P > 0.05 was considered significant. No correlation was observed between total score of placental acute inflammation and the interval membrane rupture-to-delivery (r = 0.068, 95% confidence interval –0.075, 0.211; P = 0.35). There was no evidence that the rate of maternal (P = 0.4) or neonatal (P = 0.15) infectious morbidity, or the total score of acute placental inflammation (P = 0.13), acute amnionitis (P = 0.35), choriodeciduitis (P = 0.46), chorionic plate inflammation (P = 0.38), or umbilical and chorionic vasculitis (P = 0.06) increase with the prolongation of the PROM-to-delivery interval. This study had an 85% power to detect the lack of association that was actually observed. The rate of histologic evidence of chorioamnionitis in preterm PROM does not increase with the duration of the PROM-to-delivery interval.     

Amniotic fluid soluble Toll-like receptor 4 in pregnancies complicated by preterm prelabor rupture of the membranes

Objective: To determine amniotic fluid soluble Toll-like receptor 4 (sTLR4) levels in women with preterm prelabor rupture of the membranes according to the presence of microbial invasion of the amniotic cavity and histological chorioamnionitis and its relation to neonatal outcome. Methods: One hundred two women with singleton pregnancies with a gestational age between 24?+?0 and 36?+?6 weeks were included in a prospective cohort study. Amniocenteses were performed, and the concentrations of sTLR4 in the amniotic fluid were determined using sandwich enzyme-linked immunosorbent assay technique. Results: Women with the presence of microbial invasion of the amniotic cavity had higher sTLR4 levels [median 54.2?ng/mL, interquartile range (IQR) 10.15–289.9] than those without this condition (median 18.1?ng/mL, IQR 8.1–29.9; p?=?0.001). Women with the presence of histological chorioamnionitis had a higher sTLR4 level (median 28.0?ng/mL, IQR 11.15–178.1) compared with women without histological chorioamnionitis (median 13.0?ng/mL, IQR 7.8–28.7; p?=?0.003). A mixed linear model was used to adjust for confounders. The difference was found only between women with and without microbial invasion of the amniotic cavity in this model. Conclusions: Microbial invasion of the amniotic cavity was associated with higher amniotic fluid sTLR4 levels independent of confounders.     

Comparison of changes in etiologic microorganisms causing early-onset neonatal sepsis between preterm labor and preterm premature rupture of membranes

Objective: To investigate changes in the etiologic microorganisms causing early-onset neonatal sepsis (EONS) in preterm labor (PTL) or preterm premature rupture of membranes (pPROM) cases over the past 16 years and to analyze the associated factors.

Methods: We included consecutive singleton pregnancies delivered before 34 weeks due to PTL or pPROM. The etiologic microorganisms causing EONS in PTL and pPROM cases were compared between period 1 (1996–2004) and period 2 (2005–2012).

Results: There was no difference in the incidence of Gram-positive bacteria causing EONS between period 1 and 2, either in PTL (2.0% versus 2.1%, p?=?1.0) or in pPROM (1.5% versus 1.6%, p?=?1.0). However, the incidence of EONS caused by Gram-negative bacteria was significantly increased in pPROM (0.6% versus 2.7%, p?=?0.040) during period 2, compared to period 1; but not in PTL (0.3% versus 1.2%, p?=?0.211). Multivariable analysis revealed that a prolonged ROM-to-delivery interval (>7?d) was significantly associated with EONS caused by Gram-negative bacteria in pPROM (odds ratio: 6.6, 95% confidence interval: 1.4–31.8, p?=?0.018).

Conclusions: The etiologic microorganisms causing EONS have changed over the past 16 years in pPROM cases but not in PTL cases.     

Microbial invasion and histological chorioamnionitis upregulate neutrophil-gelatinase associated lipocalin in preterm prelabor rupture of membranes

Our recent exploratory proteomic study suggested increased levels of neutrophil-gelatinase associated lipocalin (P80188, NGAL_HUMAN) due to microbial invasion of the amniotic cavity (MIAC) and histological chorioamnionitis (HCA) in women with preterm prelabor rupture of the membranes. In this study, we verified the proteomics findings by assessing the amniotic fluid NGAL by ELISA in the original exploratory cohort. The NGAL level was significantly higher in women positive for both MIAC and HCA compared to women with both conditions ruled out (median 75.1?ng/ml versus 27.9?ng/ml; p?<?0.0001). For independent validation and to assess NGALs potential to stratify women positive for both MIAC and HCA from women in whom at least one of these conditions was absent, we subsequently designed a retrospective replication cohort. Significantly higher NGAL levels were found in women positive for both MIAC and HCA (median 65.9?ng/ml versus 34.2?ng/ml; p?=?0.0061). Significantly higher levels of NGAL were confirmed only in strata below 32 weeks of gestation. Based on the observed likelihood ratio, the best predictive cutoff level (47.1?ng/ml) was evaluated in both cohorts. Data from the verification cohort implied that NGAL is a valuable clinical marker for revealing MIAC leading to HCA; however, this potential was not replicated in the replication cohort.     

Interleukin 18 messenger RNA and proIL-18 protein expression in chorioamniotic membranes from pregnant women with preterm prelabor rupture of membranes

Objective

To quantify the expression of IL-18 mRNA and protein in the chorioamniotic membranes of pregnant women with PPROM and correlate expression with histological chorioamnionitis.

Study design

A case control study that included 42 pregnant women not in labor in the following groups: PPROM (n = 28) and controls with intact membranes submitted to selective cesarean section at term (n = 14). Expression of IL-18 mRNA in chorioamniotic membranes was determined by real-time polymerase chain reaction, and IL-18 protein expression was measured by western blot. Histopathological analyses and immunolocalization of IL-18 by immunohistochemistry were also performed. Analyses were performed using the Mann–Whitney or Fisher's exact tests and the group effect was considered significant if the adjusted p-values were <0.05 and the magnitude of change was greater than 2-fold for mRNA expression.

Results

IL-18 mRNA was present in 100% of samples and no difference in expression was observed between term vs. PPROM membranes (fold-change 0.12; p = 0.88). In the PPROM group, no difference was observed in IL-18 mRNA regarding gestational age (fold-change 0.11; p = 0.42) or the presence of histological chorioamnionitis (fold-change 0.26; p = 0.15). ProIL-18 was present in all samples. IL-18 was immunolocalized to amnion, chorion and decidua cells, with intense immunohistochemical staining at the choriodecidual junction.

Conclusion

Chorioamniotic membranes are sources of IL-18 mRNA and proIL-18, and their expression is unrelated to PPROM or histological chorioamnionitis.     

Use of urea and creatinine levels in vaginal fluid for the diagnosis of preterm premature rupture of membranes and delivery interval after membrane rupture

Objective: To determine whether urea and creatinine measurements in vaginal fluid could be used to diagnose preterm premature rupture of membranes (PPROM) and predict delivery interval after PPROM.

Methods: A prospective study conducted with 100 pregnant women with PPROM and 100 healthy pregnant women between 24?+?0 and 36?+?6 gestational weeks. All patients underwent sampling for urea and creatinine concentrations in vaginal fluid at the time of admission. Receiver operator curve analysis was used to determine the cutoff values for the presence of PPROM and delivery within 48?h after PPROM.

Results: In multivariate logistic regression analysis, vaginal fluid urea and creatinine levels were found to be significant predictors of PPROM (p?p?p?=?0.012 and p?=?0.017, respectively). The optimal cutoff values for the diagnosis of PPROM were >6.7?mg/dl for urea and >0.12?mg/dl for creatinine. The optimal cutoff values for the detection of delivery within 48?h were >19.4?mg/dl for urea and >0.23?mg/dl for creatinine.

Conclusion: Measurement of urea and creatinine levels in vaginal fluid is a rapid and reliable test for diagnosing and also for predicting delivery interval after PPROM.