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Background: Despite extensive research, the identification of effective biomarkers for early prediction of preterm birth (PTB) continues to be a challenging endeavor. This study aims to identify amniotic fluid (AF) protein biomarkers useful for the early diagnosis of PTB., Methods: We initially identified the protein expression profiles in the AF of women with PTB (n = 22) and full-term birth (FTB, n = 22), from the First People's Hospital of Yunnan Province who underwent amniocentesis from November 2019 to February 2020, using mass spectrometry employing the data-independent acquisition (DIA) technique, and then analyzed differentially expressed proteins (DEPs). Subsequently, the least absolute shrinkage and selection operator (LASSO) and random forest analysis were employed to further screen the key proteins for PTB biomarker identification. The receiver operating characteristic (ROC) analysis, calibration plots, and decision curve analyses (DCA) were utilized to assess the discrimination and calibration of the key biomarkers., Results: A total of 25 DEPs were identified between the PTB and FTB groups, comprising 13 up-regulated and 12 down-regulated proteins. Three key protein biomarkers for early PTB diagnosis were identified: IL1RL1 (interleukin-1 receptor-like 1), APOE (apolipoprotein E), and NECTIN4 (nectin cell adhesion molecule 4). The results of the ROC analysis showed that the area under the curve (AUC) of the three proteins combined as a biomarker for early diagnosis of PTB was 0.913 (95% CI: 0.823-1.000), with a sensitivity of 0.864 and a specificity of 0.955, both superior to those of the individual biomarkers. Bootstrap internal validation revealed a concordance index (C-index) of 0.878, with a sensitivity of 0.812 and a specificity of 0.773, indicating the robust predictive performance of these biomarkers., Conclusions: We identified three previously unexplored yet potentially useful protein biomarkers in AF for early PTB diagnosis: IL1RL1, APOE, and NECTIN4., (© 2024. The Author(s).)

This study aimed to investigate the regulation of amniotic fibroblast (AFC) function by vitamin K-dependent protein Z (PROZ) during preterm birth (PTB) and its potential role in adverse pregnancy outcomes. Proteomic samples were collected from amniotic fluid in the second trimester, and AFC were isolated from the amniotic membrane and cultured in vitro. The expression of extracellular and intracellular PROZ in AFC was modulated, and their biological properties and functions were evaluated. Clinical analysis revealed a significant upregulation of PROZ expression in amniotic fluid from preterm pregnant women. In vitro experiments demonstrated that PROZ stimulated AFC migration, enhanced their proliferative capacity, and reduced collagen secretion. Overexpression of PROZ further enhanced cell migration and proliferation, while knockdown of PROZ had the opposite effect. PROZ plays a crucial role in promoting the proliferation and migration of amniotic membrane fibroblasts. Increased PROZ expression in amniotic fluid is associated with the occurrence of PTB. These findings shed light on the potential involvement of PROZ in adverse pregnancy outcomes and provide a basis for further research on its regulatory mechanisms during PTB., (© 2024. The Author(s).)

Objective: We aimed to determine whether the semi-quantitative metalloproteinase-8 (MMP-8) bedside test is a worthwhile indicator in reflecting the severity of of intra-amniotic inflammation (IAI) and in predicting adverse pregnancy outcomes., Study Design: This retrospective cohort study comprised 76 singleton-pregnant women admitted to the Seoul National University Bundang Hospital with a diagnosis of preterm premature rupture of membranes (preterm PROM) between 20 weeks 0 days and 33 weeks 6 days of gestation who underwent trans-abdominal amniocentesis to confirm intra-amniotic infection by positive results for aerobic/anaerobic bacteria, fungi, and genital mycoplasma and evaluate lung maturity. The semi-quantitative MMP-8 rapid test kit employs a colourimetric assay to quantify MMP-8 levels in amniotic fluid (AF), expressing results from 0 to 100 percent. Participants were divided into three groups: group 1, including negative MMP-8 test with colour scale of 0 % (negative, n = 17); group 2, including positive MMP-8 test with colour scale < 51 % (weak positive, n = 21); and group 3, including positive MMP-8 test with colour scale of 51 %-100 % (strong positive, n = 38)., Results: Approximately 78 % (59/76) of the participants showed a positive MMP-8 test result; all culture-proven AF samples (33.3 % [25/75]) yielded positive MMP-8 test, categorizing these patients into either group 2 or group 3. A significant trend was observed where the rate of positive culture-proven samples increased with the progression from group 1 (negative) to group 3 (strong positive). Both white blood cell counts in AF and maternal serum C-reactive protein levels were found to escalate with the progression of test results from negative to strong positive. This progression was associated with an increased risk of spontaneous preterm birth within 48 h, 7 days, and 14 days from amniocentesis and within 34 weeks of gestation., Conclusion: The more the test results progress from negative to strong positive, the shorter the interval from amniocentesis to delivery becomes, and the higher the risk of intra-amniotic infection, spontaneous preterm delivery, and other perinatal complications. This relationship highlights the critical value of the semi-quantitative MMP-8 rapid test in predicting adverse pregnancy outcomes in patients with preterm PROM., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction: Spontaneous preterm delivery (<37 gestational weeks) has a multifactorial etiology with still incompletely identified pathways. Amniotic fluid is a biofluid with great potential for insights into the feto-maternal milieu. It is rich in metabolites, and metabolic consequences of inflammation is yet researched only to a limited extent. Metabolomic profiling provides opportunities to identify potential biomarkers of inflammatory conditioned pregnancy complications such as spontaneous preterm delivery., Objective: The aim of this study was to perform metabolomic profiling of amniotic fluid from uncomplicated singleton pregnancies in the mid-trimester to identify potential biomarkers associated with spontaneous preterm delivery and gestational duration at delivery. A secondary aim was to replicate previously reported mid-trimester amniotic fluid metabolic biomarkers of spontaneous preterm delivery in asymptomatic women., Method: A nested case-control study was performed within a larger cohort study of asymptomatic pregnant women undergoing mid-trimester genetic amniocentesis at 14-19 gestational weeks in Gothenburg, Sweden. Medical records were used to obtain clinical data and delivery outcome variables. Amniotic fluid samples from women with a subsequent spontaneous preterm delivery ( n  = 37) were matched with amniotic fluid samples from women with a subsequent spontaneous delivery at term ( n  = 37). Amniotic fluid samples underwent untargeted metabolomic analyses using liquid chromatography-mass spectrometry. Multivariate random forest analyses were used for data processing. A secondary targeted analysis was performed, aiming to replicate previously reported mid-trimester amniotic fluid metabolic biomarkers in women with a subsequent spontaneous preterm delivery., Results: Multivariate analysis did not distinguish the samples from women with a subsequent spontaneous preterm delivery from those with a subsequent term delivery. Neither was the metabolic profile associated with gestational duration at delivery. Potential metabolic biomarker candidates were identified from four publications by two different research groups relating mid-trimester amniotic fluid metabolomes to spontaneous PTD, of which fifteen markers were included in the secondary analysis. None of these were replicated., Conclusions: Metabolomic profiles of early mid-trimester amniotic fluid were not associated with spontaneous preterm delivery or gestational duration at delivery in this cohort.

Preterm birth is an important determinant of neonatal morbidity and mortality and intra-amniotic infection (IAI) and inflammation play a causative role. The constitutive proteasome and immunoproteasome are key players in maintenance of proteostasis and their alteration outside pregnancy has been linked to pathogenesis of numerous inflammatory diseases. Our goal was to evaluate the levels, activities, and potential origin of amniotic fluid (AF) proteasome in women with preterm birth induced by infection and/or inflammation. Total proteasome and immunoproteasome concentrations were measured in AF retrieved by trans-abdominal amniocentesis from 155 pregnant women. Proteasome activities were measured with fluorogenic substrates targeting caspase-like (CAS-L), trypsin-like (TRY-L), or chymotrypsin-like (CHE-L) lytic activities. We found that IAI significantly upregulated AF concentrations of total proteasome and of the immunoproteasome (P<0.001 for both) with no differences based on gestational age. Based on substrate preference and profile of pharmacologic inhibition, we identified the CHE-L activity of the immunoproteasome as the primary lytic activity upregulated in AF of pregnancies complicated by IAI. When compared with matched maternal blood and cord blood, proteasome activity was by far the highest in AF and this was further elevated in IAI. Western blot confirmed β5 (PSMB5) and β5i (PSMB8) subunits of the constitutive proteasome and immunoproteasome are present in AF and IHC staining of fetal membranes pointed to chorio-decidua as a potential source. In conclusion, IAI is associated with increased AF immunoproteasome activity that by analogy with other inflammatory diseases may generate antigenic oligopeptides and may play a role in triggering preterm birth., (© 2021. Society for Reproductive Investigation.)

Objectives: Intra-amniotic infection, defined by the presence of microorganisms in the amniotic cavity, is often accompanied by intra-amniotic inflammation. Occasionally, laboratories report the growth of bacteria or the presence of microbial nucleic acids in amniotic fluid in the absence of intra-amniotic inflammation. This study was conducted to determine the clinical significance of the presence of bacteria in amniotic fluid samples in the absence of intra-amniotic inflammation., Methods: A retrospective cross-sectional study included 360 patients with preterm labor and intact membranes who underwent transabdominal amniocentesis for evaluation of the microbial state of the amniotic cavity as well as intra-amniotic inflammation. Cultivation techniques were used to isolate microorganisms, and broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was utilized to detect the nucleic acids of bacteria, viruses, and fungi., Results: Patients whose amniotic fluid samples evinced microorganisms but did not indicate inflammation had a similar perinatal outcome to those without microorganisms or inflammation [amniocentesis-to-delivery interval (p=0.31), spontaneous preterm birth before 34 weeks (p=0.83), acute placental inflammatory lesions (p=1), and composite neonatal morbidity (p=0.8)]., Conclusions: The isolation of microorganisms from a sample of amniotic fluid in the absence of intra-amniotic inflammation is indicative of a benign condition, which most likely represents contamination of the specimen during the collection procedure or laboratory processing rather than early colonization or infection., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Objective: We sought to identify novel biomarkers in the amniotic fluid (AF) related to imminent spontaneous preterm delivery (SPTD) (≤ 14 days after sampling) in women with early preterm premature rupture of membranes (PPROM), using a protein microarray., Method: This was a retrospective cohort study of a total of 88 singleton pregnant women with PPROM (23+0 to 30+6 weeks) who underwent amniocentesis. A nested case-control study for biomarker discovery was conducted using pooled AF samples from controls (non-imminent delivery, n = 15) and cases (imminent SPTD, n = 15), which were analyzed using an antibody microarray. Quantitative validation of four candidate proteins was performed, using ELISA, in the total cohort (n = 88). IL-8, MMP-9, and Fas levels were additionally measured for the comparison and to examine association of SPTD with the etiologic factors of PPROM., Results: Of all the proteins studied in the protein microarray, four showed significant intergroup differences. Analyses of the total cohort by ELISA confirmed the significantly elevated concentrations of AF lipocalin-2, MMP-9, and S100 A8/A9, but not of endostatin and Fas, in women who delivered within 14 days of sampling. For inflammatory proteins showing a significant association, the odds of SPTD within 14 days increased significantly with an increase in baseline AF levels of the proteins (P for trend <0.05 for each) in each quartile, especially in the 3rd and 4th quartile., Conclusions: We identified several potential novel biomarkers (i.e., lipocalin-2, MMP-9, and S100 A8/A9) related to SPTD within 14 days of sampling, all of which are inflammation-related molecules. Furthermore, the SPTD risk increased with increasing quartiles of each of these inflammatory proteins, especially the 3rd and 4th quartile of each protein. The present findings may highlight the importance of inflammatory mechanisms and the degree of activated inflammatory response in developing SPTD in early PPROM., Competing Interests: The authors have declared that no competing interests exist.

We sought to identify biomarkers in the amniotic fluid (AF) and specific signaling pathways related to spontaneous preterm delivery (SPTD, < 34 weeks) in women with preterm labor (PTL) without intra-uterine infection/inflammation (IUI). This was a retrospective cohort study of a total of 139 PTL women with singleton gestation (24 + 0 to 32 + 6 weeks) who underwent amniocentesis and who displayed no evidence of IUI. A nested case-control was conducted using pooled AF samples (n = 20) analyzed via label-free liquid chromatography-tandem mass spectrometry. In the total cohort, an ELISA validation study was performed for seven candidate proteins of interest. Proteomic analysis identified 77 differentially expressed proteins (DEPs, P < 0.05) in the AF from SPTD cases compared to term delivery controls. ELISA validation confirmed that women who had an SPTD before 34 weeks had significantly independently lower levels of VEGFR-1 and higher levels of lipocalin-2 and the Fc fragment of IgG binding protein in the AF. Five principle pathways associated with the 77 DEPs were identified, including glycolysis, gluconeogenesis, and iron homeostasis. The proteomic analysis data of AFs from women with PTL identified several novel biomarkers and specific protein pathways related to SPTD in the absence of IUI.

Introduction: To evaluate cervicovaginal fluid quantitative fetal fibronectin, measured by a bedside analyzer, to predict spontaneous preterm birth in twin pregnancy before 30 weeks of gestation., Material and Methods: In a prospective cohort study, we studied the accuracy of quantitative fetal fibronectin measured between 18 and 27 +6 weeks of gestation in high-risk asymptomatic women with twin pregnancies, to predict spontaneous preterm birth before 30 weeks of gestation. Predefined fetal fibronectin thresholds were ≥10, ≥50 and ≥200 ng/mL. Predictive statistics were also calculated to evaluate accuracy of "early" tests, performed between 18 and 21 +6 weeks and "standard" tests performed between 22 +0 and 27 +6 weeks of gestation in the same cohort. Subgroup analysis was performed according to cervical length measurement. In addition, we compared accuracy of prediction with quantitative fetal fibronectin measured during the standard test period in asymptomatic twin pregnancy with no additional risk factors, to twin pregnancies with one or more additional risk factors for spontaneous preterm birth., Results: Of 130 eligible women identified with quantitative fetal fibronectin tests undertaken during the standard testing period, 9% delivered before 30 weeks of gestation. Quantitative fetal fibronectin was significantly related to outcome before 30/40 (ROC curves of 0.8 [95% CI 0.7-1]). Early tests were not significantly predictive; ROC area 0.53 (95% CI 0.29-0.81). There was a trend towards better predictive accuracy when one or more additional risk factors for spontaneous preterm birth or cervical length were considered., Conclusions: Quantitative fetal fibronectin measured from 22 to 27 +6 weeks of gestation accurately predicts spontaneous preterm birth at <30 weeks of gestation. Tests undertaken earlier are of limited value. Consideration of cervical length or prior history in addition to quantitative fetal fibronectin strengthens prediction., (© 2020 King's College London. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Background: The two most commonly used nomograms for amniotic fluid index (AFI) were developed by Moore and Cayle and Magann et al. However, there are several inconsistencies between the two methods. Objective: The aim of the study was to determine whether these differences carry clinical significance. Methods: A retrospective cohort of women with singleton pregnancies evaluated for AFI during pregnancy at a tertiary medical center in 2007-2014 were divided into five groups: group A, definite oligohydramnios-AFI below the fifth percentile according to the nomograms of both Moore and Cayle and Magann et al.; group B, intermediate oligohydramnios-AFI below the fifth percentile according to only one nomogram (Moore and Cayle); group C, euhydramnios-normal AFI according to both nomograms; group D, intermediate polyhydramnios-AFI above the 95th percentile according to one nomogram (Magann et al.); group E, definite polyhydramnios-above the 95th percentile according to both nomograms. The association of group by maternal and perinatal outcomes was analyzed. Results: A total of 6987 women were included: group A, 996 (14%); group B, 1344 (19%); group C, 2561 (37%); group D, 1051 (15%); group E, 1034 (15%). Group B (intermediate oligohydramnios) was characterized by significantly lower rates of adverse perinatal outcomes than group A (definite oligohydramnios): small for gestational age neonate (12.3 versus 15.2%, p  = .05), neonatal intensive care unit admission (11.1 versus 21.5%; p  < .001), composite respiratory outcome (4.8 versus 9.8%; p  < .001), and neonatal sepsis (6.4 versus 10.8%; p  < .001). No such differences were found between groups B and C. Group D (intermediate polyhydramnios) differed from group E (definite polyhydramnios) by lower rates of 5 minutes Apgar score <7 (1.3 versus 3.2%; p  = .003), neonatal intensive care unit admission (10.9 versus 14.4%; p  = .02), and major congenital anomalies (1.7 versus 5.6%; p  = .02). There was no difference in these parameters between groups D and C. Conclusion: This study suggests that intermediate oligohydramnios and intermediate polyhydramnios are not associated with adverse perinatal outcomes. Outcome in these pregnancies is similar to pregnancies with euhydramnios. Commonly used AFI nomograms should be updated.

Problem: Cervical insufficiency is a precursor of preterm birth. Treatment with emergency cervical cerclage is contraindicated in the presence of intra-amniotic infection. Detecting infection with Gram stain and culture of amniotic fluid lacks sensitivity. Proteomic profiling of amniotic fluid in cervical insufficiency may help identify pregnancies best suited for emergency cerclage., Method of Study: Thirty-two pregnant women underwent amniocentesis for routine genetic testing (n = 22) or after diagnosis of cervical insufficiency (n = 10). The proteomic profiles of the amniotic fluid samples were compared in a cross-sectional fashion, including sub-analyses of women with cervical insufficiency and latency periods of <1 week and >1 week post-diagnosis., Results: Mean gestational age at diagnosis of cervical insufficiency was 21.4 weeks (95% CI 20.6-22.1). Proteomic analysis yielded 40 (7.2%, P < 0.05) differentially expressed proteins between women with delivery <1 week (n = 6) vs. >1 week (n = 4). Women who delivered <1 week had activated inflammatory response (z = 2.3, P = 6.71E-09), chemotaxis of immune cells (z = 2.9, P = 2.01E-08), and inhibited bacterial growth (z = -2.2, P = 5.82E-05). A multivariate model of eight biomarkers positively associated with cases of <1 week latency and distinguished cases from controls (97.8%, cross-validation accuracy 92.7%, P = 0.0009)., Conclusion: In this pilot study, significant differences in the amniotic fluid proteomic profiles in cases of cervical insufficiency compared to genetic amniocentesis were observed. Proteomic signatures were predictive of achieving latency > 1 week after diagnosis of cervical insufficiency. These preliminary findings suggest that proteomic analysis may be of value in predicting outcome following cervical insufficiency and warrants further validation in larger studies., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: The objective of this study is to determine whether the amniotic fluid (AF) concentration of soluble CXCR3 and its ligands CXCL9 and CXCL10 changes in patients whose placentas show evidence of chronic chorioamnionitis or other placental lesions consistent with maternal anti-fetal rejection., Methods: This retrospective case-control study included 425 women with (1) preterm delivery (n=92); (2) term in labor (n=68); and (3) term not in labor (n=265). Amniotic fluid CXCR3, CXCL9 and CXCL10 concentrations were determined by ELISA., Results: (1) Amniotic fluid concentrations of CXCR3 and its ligands CXCL9 and CXCL10 are higher in patients with preterm labor and maternal anti-fetal rejection lesions than in those without these lesions [CXCR3: preterm labor and delivery with maternal anti-fetal rejection placental lesions (median, 17.24 ng/mL; IQR, 6.79-26.68) vs. preterm labor and delivery without these placental lesions (median 8.79 ng/mL; IQR, 4.98-14.7; P=0.028)]; (2) patients with preterm labor and chronic chorioamnionitis had higher AF concentrations of CXCL9 and CXCL10, but not CXCR3, than those without this lesion [CXCR3: preterm labor with chronic chorioamnionitis (median, 17.02 ng/mL; IQR, 5.57-26.68) vs. preterm labor without chronic chorioamnionitis (median, 10.37 ng/mL; IQR 5.01-17.81; P=0.283)]; (3) patients with preterm labor had a significantly higher AF concentration of CXCR3 than those in labor at term regardless of the presence or absence of placental lesions., Conclusion: Our findings support a role for maternal anti-fetal rejection in a subset of patients with preterm labor.

Objective:  The objective of this study was to evaluate the association of screening tests for preterm birth (short cervical length [CL], positive fetal fibronectin (FFN), and amniotic fluid [AF] sludge) in twin gestations with histologic evidence of placental inflammation., Study Design:  Historical cohort study of 596 twin gestations delivered in a single maternal-fetal medicine practice with CL and FFN testing from 22 to 25 6/7 weeks. A short CL was defined as ≤25 mm. Placental lesions evaluated were chronic and acute membrane inflammation and funisitis. Fischer's exact test and logistic regression were used., Results:  None of the screening tests was associated with chronic inflammation. All were associated with acute inflammation. On regression analysis, a short CL and positive FFN remained independently associated with acute inflammation (adjusted odds ratio [aOR]: 5.66 and 2.51, respectively) and funisitis (aOR: 5.66 and 7.17, respectively). AF sludge was not independently associated with acute inflammation nor funisitis., Conclusion:  In twin gestations, a short CL and a positive FFN at 22 to 26 weeks are associated with acute but not chronic inflammation on placental histology. These findings imply that mechanisms underlying preterm birth in twins that result in positive screening tests weeks prior to delivery are not reflected as chronic placental inflammation. Therefore, pathologic interpretation of etiologic mechanisms for preterm birth may be limited using solely histologic reports., Competing Interests: None., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Objective: To determine the value of early- or mid-trimester amniotic fluid levels of interleukin-6 (IL-6), matrix metalloproteinase-8 (MMP-8), and glucose for predicting preterm delivery., Methods: Randomized controlled trials and two-arm prospective, retrospective, cohorts, and case-controlled studies in which patients received early- or mid-trimester amniocentesis for karyotyping, and biomarker testing of the amniotic fluid was performed and delivery data were available were included in the analysis., Results: Outcome measures were the associations of amniotic fluid IL-6, MMP-8, and glucose levels with preterm delivery. Differences in means with 95% confidence intervals (CIs) were calculated. Of 288 articles identified, 14 were included in the meta-analysis with a total of 675 patients who had preterm birth and 2518 patients who had term births. The preterm-delivery group had significantly higher amniotic fluid IL-6 and MMP-8 levels, and a significantly lower glucose level than the term delivery group (IL-6: difference in means = 0.32, 95% CI: 0.22-0.43, p < 0.001; MMP-8: difference in means = 4.47, 95% CI: 0.83-8.11), p = 0.016; glucose: difference in means = -5.22, 95% CI: -8.19 to -2.26, p = 0.001) Conclusion: Early- or mid-trimester amniotic fluid IL-6, MMP-8, and glucose levels are useful for predicting the risk of preterm delivery. KEY MESSAGES Median amniotic fluid ferritin and IL-6 levels, and mean amniotic fluid ALP levels were higher in the preterm group. The preterm-delivery group had significantly higher amniotic fluid IL-6 and MMP-8 levels, and a significantly lower glucose level than the term-delivery group.

Introduction . Intra-amniotic infection (IAI) is a major cause of preterm labor and adverse neonatal outcome. We evaluated amniotic fluid (AF) proteolytic cascade forming biomarkers in relation to microbial invasion of the amniotic cavity (MIAC) and IAI in preterm pregnancies with intact membranes. Material and Methods . Amniocentesis was made to 73 women with singleton pregnancies; 27 with suspected IAI; and 46 controls. AF biomarkers were divided into three cascades: Cascade 1: matrix metalloproteinase-8 (MMP-8), MMP-9, myeloperoxidase (MPO), and interleukin-6; Cascade 2: neutrophil elastase (HNE), elafin, and MMP-9; Cascade 3: MMP-2, tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), MMP-8/TIMP-1 molar ratio, and C-reactive protein (CRP). MMP-8 was measured by an immunoenzymometric assay and the others were measured by ELISA. Standard biochemical methods, molecular microbiology, and culture techniques were used. Results . MMP-8, MMP-9, MPO, elafin, and TIMP-1 concentrations were higher in IAI suspected cases compared to controls and also in IAI suspected cases with MIAC compared to those without MIAC when adjusted by gestational age at amniocentesis. All biomarkers except elafin and MMP-2 had the sensitivity of 100% with thresholds based on ROC-curve. Odd ratios of biomarkers for MIAC were 1.2-38 and 95% confidential intervals 1.0-353.6. Conclusions . Neutrophil based AF biomarkers were associated with IAI and MIAC., Competing Interests: The authors declare that there is no conflict of interests regarding the publication of this paper.

Aim: The purpose of this study is to determine whether proinflammatory cytokines and matrix metalloproteinases (MMPs) in amniotic fluid (AF), alone or in combination with clinical risk factors, can predict spontaneous preterm delivery (SPTD) at < 34 weeks in women with cervical insufficiency., Methods: This retrospective cohort study included 57 consecutive singleton pregnant women (17-28 gestational weeks) with cervical insufficiency who underwent amniocentesis. AF was assayed for five cytokines (interleukin [IL]-6, IL-8, monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1α, and MIP-1β) and five MMPs (MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9) using multiplex immunoassay kits. The primary outcome measure was SPTD at < 34 weeks., Results: The AF concentrations of MMP-1, MMP-3, MMP-8, MMP-9, IL-6, IL-8, MIP-1α and MIP-1β were significantly higher in women with SPTD at < 34 weeks. Women who had SPTD at < 34 weeks were younger, had significantly more advanced cervical dilatation at presentation and a higher rate of positive AF cultures. Using stepwise regression analysis, a combined prediction model was developed that included maternal age, cervical dilatation at presentation, AF MMP-1 and AF MMP-8 (area under the curve [AUC] 0.951). The AUC for this model was significantly greater than for any single protein alone in AF or for each of the clinical risk factors alone., Conclusion: A model combining proteins in AF and clinical factors can improve the accuracy of risk prediction for preterm birth and this combination is more accurate than each of the biomarkers alone in women with cervical insufficiency., (© 2016 Japan Society of Obstetrics and Gynecology.)

Objective: The aim of this study was to identify early proteomic biomarkers of spontaneous preterm delivery (PTD) in mid-trimester amniotic fluid from asymptomatic women., Methods: This is a case-cohort study. Amniotic fluid from mid-trimester genetic amniocentesis (14-19 weeks of gestation) was collected from 2008 to 2011. The analysis was conducted in 24 healthy women with subsequent spontaneous PTD (cases) and 40 randomly selected healthy women delivering at term (controls). An exploratory phase with proteomics analysis of pooled samples was followed by a verification phase with ELISA of individual case and control samples., Results: The median (interquartile range (IQR: 25th; 75th percentiles) gestational age at delivery was 35+5 (33+6-36+6) weeks in women with spontaneous PTD and 40+0 (39+1-40+5) weeks in women who delivered at term. In the exploratory phase, the most pronounced differences were found in C-reactive protein (CRP) levels, that were approximately two-fold higher in the pooled case samples than in the pooled control samples. However, we could not verify these differences with ELISA. The median (25th; 75th IQR) CRP level was 95.2 ng/mL (64.3; 163.5) in women with spontaneous PTD and 86.0 ng/mL (51.2; 145.8) in women delivering at term (p = 0.37; t-test)., Conclusions: Proteomic analysis with mass spectrometry of mid-trimester amniotic fluid suggests CRP as a potential marker of spontaneous preterm delivery, but this prognostic potential was not verified with ELISA.

Objectives: To examine the efficacy of the use of antibiotics in preterm labor (PTL) with intact membranes, after evaluating intra-amniotic microbes by our rapid and bacteria-free polymerase chain reaction (PCR) system., Materials and Methods: One hundred and four PTL patients before 32 weeks of gestation were recruited. Until 2012, antibiotics were empirically prescribed based on the clinical severity of PTL. Intra-amniotic microbes in stored samples were evaluated later by our newly established PCR system, and the efficacy of the use of antibiotics in PTL was evaluated., Results: In the amniotic fluid (AF) microbe-negative patients (n = 67), antibiotic therapy significantly shortened the gestation period (P < 0.0001), whereas in the microbe-positive patients (n = 37), appropriate antibiotic therapy (proper antibiotic selection against identified AF microbes) was significantly associated with an increase in gestation period (P < 0.0001)., Conclusion: Appropriate antibiotic therapy in PTL with intact membranes prolonged the gestation period., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Amniotic fluid (AF) is a biological fluid in which metabolite transport is regulated by the placenta, the permeable skin, fetal lung egress and gastric fluid. During pregnancy, the composition of AF changes from similar to the interstitial fluid of the mother, to a more complex system, influenced by the fetus's urine. Since AF reflects the mother's and the fetus's health status at the same time, it may be an important diagnostic tool for a wider spectrum of clinical conditions. Indeed, the metabolic characterization of AF in relation to pathological occurrences may lead to the discovery of new biomarkers for a better clinical practice. For this reason, metabolomics may be the most suitable strategy for this task. In this review, research works on metabolomic AF analysis are discussed according to the morbidity of interest, being preterm birth/labor, gestational age and diabetes and fetal malformations, along with a number of other important studies.

Objective: To determine whether an elevated amniotic fluid concentration of prostaglandin F2α (PGF2α) 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). PGF2α was measured with a sensitive and specific immunoassay. The amniotic fluid PGF2α 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 PGF2α concentration was 40.2% (53/132) in patients with preterm labor and intact membranes; (2) patients with an elevated amniotic fluid PGF2α 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 PGF2α (p < 0.05 for each); and (3) an elevated amniotic fluid PGF2α 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 PGF2α 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.

Objective: Mid-trimester amniocentesis continues to be used for the prenatal diagnosis of chromosomal anomalies and other genetic disorders. Analysis of amniotic fluid obtained at the time of mid-trimester genetic amniocentesis identifies those patients who are at risk for early spontaneous preterm delivery. This is based on a solid body of evidence that found subclinical intra-amniotic inflammation/infection to be causally linked to early spontaneous preterm birth. Although several biomarkers have been proposed to identify intra-amniotic inflammation, the accumulated data suggest that the determination of amniotic fluid matrix metalloproteinase-8 (MMP-8), or neutrophil collagenase, is a powerful predictor of spontaneous preterm delivery. MMP-8 is released by inflammatory cells in response to microbial products or "danger signals". A rapid point-of-care test has been developed to determine MMP-8 at the bedside within 20 min, and without the requirement of laboratory equipment. The objective of this study was to determine whether an elevation of MMP-8 in the amniotic fluid, measured by a rapid point-of-care test, can identify those patients at risk for spontaneous preterm delivery after a mid-trimester genetic amniocentesis., Study Design: A case-control study was designed to obtain amniotic fluid from asymptomatic singleton pregnant women who underwent mid-trimester genetic amniocentesis. An MMP-8 bedside test was performed to analyze the amniotic fluid of 64 patients with early spontaneous preterm delivery (<30 weeks) and 128 matched controls with normal pregnancy outcomes., Results: (1) The MMP-8 bedside test (Yoon's MMP-8 Check™) was positive in 42.2% (27/64) of patients with spontaneous preterm delivery but in none (0/128) of the control cases (p < 0.001); (2) the MMP-8 bedside test had a sensitivity of 42.2%, and a specificity of 100% in the prediction of spontaneous preterm delivery (<30 weeks) following a mid-trimester genetic amniocentesis; and (3) among the patients with spontaneous preterm delivery, those with a positive MMP-8 bedside test had a significantly higher rate of spontaneous delivery within 2 weeks and 4 weeks of an amniocentesis [40.7% (11/27) versus 5.4% (2/37); 63.0% (17/27) versus 24.3% (9/37)] and a shorter interval-to-delivery period than those with a negative test [interval-to-delivery: median (range), 16 d (0-95 d) versus 42 d (2-91 d); p < 0.05 for each]., Conclusion: We conclude that 42% of patients with an early spontaneous preterm delivery (< 30 weeks) could be identified by a rapid MMP-8 bedside test at the time of their mid-trimester genetic amniocentesis. The MMP-8 bedside test is a powerful predictor of early spontaneous preterm birth in asymptomatic pregnant women.

Objective: We sought to determine whether transvaginal cervical length (TVCL), amniotic fluid index (AFI), or a combination of both can predict delivery latency within 7 days in women presenting with preterm premature rupture of membranes (PPROM)., Study Design: This was a prospective observational study of TVCL measurements in 106 singleton pregnancies with PPROM between 23-33 weeks. Delivery latency was defined as the period (in days) from the initial TVCL after PPROM to delivery of the infant, with our primary outcome being delivery within 7 days of TVCL. The independent predictability of significant characteristics for delivery within 7 days was determined using multiple logistic regression. Sensitivity, specificity, and predictive values were used to examine whether the presence of a short TVCL, AFI, or a combination of both affected the risk of delivery within 7 days., Results: Delivery within 7 days occurred in 51/106 (48%) of pregnancies. Median duration (interquartile range) from PPROM to delivery and TVCL to delivery was 8 days (4.0-16.0) and 8 days (3.0-15.0), respectively. Using multiple regression TVCL as a continuous variable (odds ratio, 0.65; 95% confidence interval, 0.44-0.97; P < .05), AFI ≤5 cm (odds ratio, 4.69; 95% confidence interval, 1.58-13.93; P < .01) were determined to be independent predictors of delivery within 7 days. In all, 42 women (40%) had a TVCL ≤2 cm, while 62 (59%) had AFI ≤5 cm. A total of 26 women (25%) had a combination of both TVCL ≤2 cm and AFI ≤5 cm, while 28 women (27%) had neither characteristic. The predictive value of delivery within 7 days for a TVCL ≤2 cm was 62%, and for an AFI ≤5 cm was 58%. Having a combination of low TVCL and low AFI did not increase the predictive value of delivery within 7 days (58%). In contrast, only 3 of 27 women (11%) with neither characteristic delivered within 7 days. The predictive value of delivery >7 days for TVCL >2 cm alone was 61%. This predictive value changed when analyzed in conjunction with an AFI ≤5 cm and >5 cm at 42% and 89%, respectively., Conclusion: A shorter TVCL and an AFI ≤5 cm independently predict delivery within 7 days in women presenting with PPROM. The combination of an AFI >5 cm and TVCL >2 cm greatly improved the potential to remain undelivered at 7 days following cervical length assessment. These findings may be helpful for counseling and optimizing maternal and neonatal care in women with PPROM., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objective: To identify metabolic changes associated with early spontaneous preterm birth (PTB; <34 weeks) and term births, using high-throughput metabolomics of amniotic fluid (AF) in African American population., Method: In this study, AF samples retrieved from spontaneous PTB (<34 weeks [n = 25]) and normal term birth (n = 25) by transvaginal amniocentesis at the time of labor prior to delivery were subjected to metabolomics analysis. Equal volumes of samples were subjected to a standard solvent extraction method and analyzed using gas chromatography/mass spectrometry (MS) and liquid chromatography/MS/MS. Biochemicals were identified through matching of ion features to a library of biochemical standards. After log transformation and imputation of minimum observed values for each compound, t test, correlation tests, and false discovery rate corrections were used to identify differentially regulated metabolites. Data were controlled for clinical/demographic variables and medication during pregnancy., Results: Of 348 metabolites measured in AF samples, 121 metabolites had a gestational age effect and 116 differed significantly between PTB and term births. A majority of significantly altered metabolites could be classified into 3 categories, namely, (1) liver function, (2) fatty acid and coenzyme A (CoA) metabolism, and (3) histidine metabolism. The signature of altered liver function was apparent in many cytochrome P450-related pathways including bile acids, steroids, xanthines, heme, and phase II detoxification of xenobiotics with the largest fold change seen with pantothenol, a CoA synthesis inhibitor that was 8-fold more abundant in PTB., Conclusion: Global metabolic profiling of AF revealed alteration in hepatic metabolites involving xenobiotic detoxification and CoA metabolism in PTB. Maternal and/or fetal hepatic function differences may be developmentally related and its contribution PTB as a cause or effect of PTB is still unclear.

Objective: To investigate the clinical significance and value in the prediction of preterm delivery of combined amniotic fluid IL-8 and Annexin A2 levels in preterm premature rupture of membranes (PPROM) and preterm labor (PTL)., Study Design: Sixty pregnant women at < 32 gestational weeks who developed PTL were divided into a PPROM group and a non-PPROM group. Ten normal pregnant women served as a control group. IL-8 and Annexin A2 levels were measured in amniotic fluid samples from each patient., Results: Amniotic fluid IL-8 and Annexin-A2 levels in PTL (PPROM and non-PPROM groups) were significantly higher than those of the controls (p < 0.05). The PPROM group displayed higher amniotic fluid Annexin-A2 levels than did the non-PPROM group, with a statistically significant difference (p < 0.05). The PPROM group showed higher amniotic fluid IL-8 levels than did the non-PPROM group; however, this was statistically insignificant (p = 0.56). Combined detection of amniotic fluid IL-8 and Annexin-A2 in the prediction of preterm delivery within 2 weeks of measurement showed sensitivity of 81.25%, specificity of 88.89% and PPV of 92.86%., Conclusion: Amniotic fluid IL-8 and Annexin-A2 levels are associated with the occurrence of PPROM and PTL. Combined detection of IL-8 and Annexin-A2 levels in identifying preterm delivery within 2 weeks in PTL and PPROM is of possible clinical and predictive value.

Aim: The aim of this study was to analyze whether urocortin-1 concentration in midtrimester amniotic fluid could serve as an indicative marker of preterm labor., Material and Methods: A retrospective cohort study was conducted. Urocortin-1 concentrations in midtrimester amniotic fluid were measured in 22 pregnant women with preterm deliveries and 45 women who delivered at term using enzyme-linked immunosorbent assay., Results: The median amniotic fluid urocortin-1 concentration was significantly lower in the women with preterm birth (40.06 pg/mL; range, 13.77-67.58 pg/mL) than in the women who gave birth at term (49.56 pg/mL; range, 26.25-175.9 pg/mL; P = 0.022). The result of receiver-operator curve analysis indicates that an amniotic fluid urocortin-1 concentration ≤ 57.88 pg/mL had an area under the curve of 0.673 (95% confidence interval, 0.55-0.78; P = 0.01) with a sensitivity of 81.8%, specificity of 40.0%, positive predictive value of 40%, and a negative predictive value of 82% in identifying which of the patients subsequently delivered prematurely., Conclusions: These results suggest that low urocortin-1 concentration in midtrimester amniotic fluid could be used as an indicative marker of preterm birth., (© 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.)

This work describes a mid-infrared (MIR) metabolic profiling study of 2nd trimester amniotic fluid in relation to selected prenatal disorders, with results focusing on fetal malformations (FM), preterm delivery (PTD) and premature rupture of membranes (PROM), the latter two conditions occurring later in pregnancy. Partial least squares-discriminant analysis (PLS-DA) models were obtained for FM and pre-PTD subject groups, supported by Monte Carlo Cross Validation (MCCV), and identified specific MIR profile changes. For pre-PROM subjects, minor changes were noted. MIR interpretation was assisted by intra- (MIR/MIR) and inter- (MIR/NMR) domain statistical correlation analysis, the results unveiling possible biomarker MIR signatures for FM and pre-PTD subjects. Biofluid MIR metabolic profiling holds enticing possibilities as a low cost, easy to use, rapid method and the results presented have shown its sensitivity to clinically diagnosed conditions such as FM, and to the pre-clinical stages of PTD. Specific improvement needs are discussed, namely regarding sample numbers and experimental reproducibility., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objective: Infection is believed to be one of frequent and important causes of preterm labor. We attempted to evaluate whether the level of inflammatory markers, e.g. interleukin-16 (IL-16), interleukin-18 (IL-18), and ferritin, in amniotic fluid at early second trimester can predict preterm birth., Methods: Amniotic fluid (AF) samples were collected from 350 pregnant women who had trans-abdominal amniocentesis for genetic indications at 16 to 20 weeks of gestation. AF levels of IL-16, IL-18 and ferritin levels were measured by immunoassay and were correlated with pregnancy outcomes., Results: Among the 350 pregnant women, 58 (16.6%) had preterm birth (<37 weeks gestation). AF levels of IL-16, IL-18, and ferritin were significantly higher in pregnant women with subsequent preterm birth. Multivariate analyses showed that a quartile higher of AF IL-16 level was significantly associated with preterm birth (OR: 3.09, 95% CI 1.52-6.27, p = 0.002). A receiver operating characteristic analysis revealed that an IL-16 cutoff value of 105 pg/ml was a reliable predictor of preterm birth (sensitivity, 90.2%; specificity, 52.7%; negative predictive value, 84.3%)., Conclusion: It is feasible to predict preterm birth by measuring the AF levels of IL-16 especially for the pregnant women requiring genetic amniocentesis during early second trimester.

Objective: The aim of this study was to identify possible biomarkers for preterm delivery by analyzing midtrimester amniotic fluid., Methods: Thirty-two amniotic fluid samples were studied; 16 patients had a spontaneous preterm delivery and 16 patients delivered at term. The proteomic technique consisted of surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF) using different types of solid chromatographic chips (Q10, CM10 and IMAC30)., Results: Mass spectrometry tracings were obtained from the amniotic fluids of both patients who delivered preterm and patients who delivered at term. Seven potential markers were identified to be differentially expressed in patients who delivered preterm., Conclusions: Proteomic analysis of amniotic fluid obtained in the midtrimester reveals the presence of a set of proteins in patients at risk for preterm delivery.

Objective: To assess midtrimester amniotic fluid concentrations of three major proinflammatory cytokines (IL-6, IL-8, and TNF-α) in asymptomatic pregnancies with adverse outcomes., Methods: A prospective follow up study at the Charité University Hospital, Berlin, Germany of women with uncomplicated singleton pregnancies at second trimester and amniocentesis. Concentrations of IL-6, IL-8, and TNF-α were measured by enzyme-linked immunosorbent assay following amniotic fluid assessment by midtrimester amniocentesis performed from gestation days 15 weeks 0 days up to 20 weeks 6 days. Values from normal pregnancies were compared to those from pregnancies having adverse outcomes of spontaneous abortion, preterm delivery, preeclampsia, or eclampsia. Main outcome measure IL-6, IL-8 and TNF-α in relation to adverse pregnancy outcome., Results: A total of 298 consecutive patients were evaluated. Median patient age was 35 years (range 19-43). Controls consisted of 273 women who delivered without further complications after 37 weeks gestation. The range values of IL-6, IL-8, and TNF-α in the control group were 4.9-2620 pg/mL, 36.2-5843 pg/mL, and 8.0-28.2 pg/mL, respectively. Patients with adverse pregnancy outcome (n = 25) were classified into three groups: spontaneous abortion group (n = 4), preterm delivery group (n = 17), and preeclampsia/eclampsia group (n = 4). There were no significant differences in IL-6, IL-8, and TNF-α between controls and study groups, regardless of the type of complication (p > 0.05)., Conclusion: Midtrimester amniotic fluid concentrations of the proinflammatory cytokines IL-6, IL-8, and TNF-α are not predictive of adverse pregnancy outcome in terms of spontaneous abortion, preterm delivery or preeclampsia/eclampsia in our study population.

Introduction: Intra-amniotic inflammation is traditionally defined as an elevation of amniotic fluid interleukin (IL)-6. Previous case control studies have suggested an association between an elevated midtrimester amniotic fluid IL-6 and preterm delivery, although such an association has been recently challenged. Intra-amniotic inflammation can also be defined by an elevation of the T-cell chemokine, Interferon-gamma-inducible protein (IP)-10. An elevation in amniotic fluid IP-10 has been associated with chronic chorioamnionitis, a lesion frequently found in late spontaneous preterm birth and fetal death. In contrast, an elevation in amniotic fluid IL-6 is typically associated with acute chorioamnionitis and funisitis. This study was conducted to examine the relationship between an elevation in amniotic fluid IL-6 in the midtrimester and preterm delivery at or before 32 weeks of gestation, and the amniotic fluid concentration of IP-10 and preterm delivery after 32 weeks of gestation., Materials and Methods: This cohort study included 847 consecutive women undergoing genetic midtrimester amniocentesis; in 796 cases, amniotic fluid and pregnancy outcome was available for study after exclusion of abnormal karyotype and/or fetal congenital anomalies. Spontaneous preterm delivery was defined as early (≤32 weeks) or late (after 32 completed weeks of pregnancy). The amniotic fluid and maternal blood concentrations of IL-6 and IP-10 were measured by specific immunoassays., Results: 1) The prevalence of preterm delivery was 8.3% (66/796), while those of early and late spontaneous preterm delivery were 1.5% (n=12), and 4.5% (n=36), respectively; 2) patients who had a spontaneous preterm delivery after 32 weeks of gestation had a higher median amniotic fluid IP-10 concentration than those who delivered at term [median 713 pg/mL, inter-quartile range (IQR) 509-1427 pg/mL vs. median 589 pg/mL, IQR 402-953 pg/mL; P=0.006] and an elevation of amniotic fluid IP-10 concentration above 502 pg/mL (derived from an ROC curve) was associated with late spontaneous preterm delivery [odds ratio 3.9 (95% CI 1.6-9.9)]; 3) patients who had a spontaneous preterm delivery ≤32 weeks of gestation had a higher median amniotic fluid IL-6 concentration than those who delivered at term [median 2052 pg/mL, IQR 435-3015 pg/mL vs. median 414 pg/mL, IQR 209-930 pg/mL; P=0.006], and an elevated amniotic fluid IL-6 concentration above 1740 pg/mL (derived from an ROC curve) was associated with early spontaneous preterm delivery [odds ratio 9.5 (95% CI 2.9-31.1)]; 4) subclinical intra-amniotic inflammation, defined as an elevation of IL-6 (≥2.9 ng/mL) or IP-10 (≥2.2 ng/mL) concentration above the 95th percentile of patients who had uncomplicated term delivery (n=652 for IL-6 and n=633 for IP-10), was observed in 6.3% (50/796) and 5.8% (45/770) of cases, respectively. Although each type of inflammation is a risk factor for spontaneous preterm delivery, many patients had a term delivery without complication; 5) the amniotic fluid in the midtrimester did not contain microorganisms detectable with cultivation techniques., Conclusions: INTRA-amniotic inflammation is heterogeneous. Some patients have elevated amniotic fluid concentrations of IL-6, and are at risk for spontaneous preterm delivery before 32 weeks of gestation, while others have an elevated IP-10 (a chemotactic T-cell chemokine) and such patients are at risk for spontaneous preterm delivery after 32 weeks of gestation. A fraction of patients have subclinical intra-amniotic inflammation and deliver at term. The clinical significance of this condition remains to be determined.

Objective: We propose a novel amniotic fluid inflammatory score from a comprehensive cytokine analysis of patients with mid-trimester short cervix., Study Design: Amniotic fluid from singleton gestations (n = 44) with a cervical length of ≤25 mm between 16-24 weeks was assayed for 25 inflammatory mediators. Patient data were stratified according to gestational age at delivery (<34 vs ≥34 weeks). Mediators that reached statistical significance were included in the amniotic fluid inflammatory score. Patients were assigned 1 point for each significant mediator if their level was in the upper quartile. The amniotic fluid inflammatory score was determined, and its relationship to other clinical characteristics was examined., Results: Fourteen mediators met the criteria. A score of ≥8 was predictive of delivery at <34 weeks' gestation (sensitivity, 87.0%; specificity, 100%; positive predictive value, 100%; negative predictive value, 87.5%). Twenty patients had a high inflammatory score (≥8); 24 patients had a low score. All patients with a high inflammatory score delivered at <30 weeks' gestation., Conclusion: The amniotic fluid inflammatory score is related to delivery outcome and clinical characteristics., (Copyright © 2012 Mosby, Inc. All rights reserved.)

Objective: To conduct a literature search for selected biomarkers on preterm delivery and estimate their likelihood ratios (LR)., Design: Structured review., Population: Low and high-risk populations and women with symptoms of preterm delivery. METHODS. Publications were identified in PubMed., Main Outcome Measures: LR on selected biomarkers for preterm delivery., Results: In asymptomatic women with low risk of preterm delivery, the following biomarkers gave major shifts in probability (LR above 5): twins (LR+ 10), Ureaplasma urealyticum in amniotic fluid (LR+ of 10), cervical length <25mm (LR+ 6), salival estriol (LR+ 5) and various combined tests. In asymptomatic women with high risk of preterm delivery, short cervical length (LR+ 11, LR- 0.7), high serum tumor necrosis factor-alpha (LR+ 10, LR- 0.6) gave major shifts in probability. In women with symptoms of preterm delivery, major shifts in probability can be obtained from the following amniotic fluid biomarkers: high matrix metalloproteinase-8 (LR+ 23, LR- 0.6), Ureaplasma urealyticum (LR+ 19, LR- 0.8), high interleukin (IL)-6 (LR+ 9, LR- 0.2), IL-8 (LR+10, LR- 0.2) and tumor necrosis factor-alpha (LR+ 8, LR- 0.4). In serum IL-6 (LR+ 12, LR- 0.2), Cluster of Differentiation 163 (LR+9, LR-0.8) and various combined tests. Vaginal fetal fibronectin (LR+ 3 and LR- 0.5) and short cervical length (LR+ 2, LR- 0.3) gave LRs of some importance (LR below 5)., Conclusion: Several biomarkers have been identified for assessment of risk of preterm delivery. Their clinical relevance depends on the efficacy of the interventions which can be offered to these patients., (© 2011 The Author Acta Obstetricia et Gynecologica Scandinavica© 2011 Nordic Federation of Societies of Obstetrics and Gynecology.)

Purpose: Early diagnosis of prelabor rupture of membranes (PROM) is essential to protect mother and fetus from intra-uterus infection and preterm birth. A simple and rapid bedside test would help clinicians confirm the diagnosis for early treatment., Experimental Design: A protein array was used to screen cervical-vaginal fluid (CVF) and amniotic fluid (AF) samples collected from normal and PROM pregnant women. Enzyme-linked immunosorbent assay was used to quantify two novel and potentially useful analytes, soluble intercellular adhesion molecule-1 (sICAM-1) and Axl receptor tyrosine kinase (Axl)., Results: The mean concentration of sICAM-1 and Axl was 85 and 482 times higher separately in 30 healthy AF samples than in 110 CVF samples of normal pregnancies. Comparing 110 CVF samples of PROM/Preterm PROM with 110 CVF samples of normal pregnancies, the diagnostic value for PROM was demonstrated by their high sensitivity and specificity (96.4 and 92.7%, respectively, for sICAM-1, and 92.4 and 90.4%, respectively, for Axl)., Conclusions and Clinical Relevance: The results indicate that sICAM-1 and Axl in AF leaked to vagina are sensitive and specific biomarkers for the diagnosis of PROM. Furthermore, sICAM-1 or Axl can be developed into a rapid strip test for bedside use., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: To determine the association of amniotic fluid sludge with impending preterm delivery in women in preterm labor with intact membranes., Methods: This was a retrospective cohort study in women at 22-34 weeks' gestation in preterm labor with intact fetal membranes between February 2008 and May 2009. 16 women with amniotic sludge were identified. Each case of amniotic sludge was matched with 3 randomly selected controls. The primary outcome was delivery within 48 h of examination., Results: Mean cervical length was shorter in women with sludge than women without sludge (20.5 ± 9.0 vs. 27.9 ± 6.9 mm, p = 0.0016). There was a significant difference in the mean ultrasound-to-delivery interval in women with and without sludge (21.7 vs. 49.4 days, p = 0.006). Logistic regression analyses demonstrated that amniotic fluid sludge is a strong independent predictor of impending preterm delivery within 48 h (OR 11.2, 95% CI 1.2-125.9), 7 days (OR 3.8, 95% CI 1.2-17.3) and 14 days (OR 7.5, 95% CI 1.8-30.4)., Conclusions: Amniotic fluid sludge on ultrasound scan is associated with impending preterm delivery in women in preterm labor with intact membranes., (2011 S. Karger AG, Basel.)

Objective: To evaluate pre- and postoperative predictors of preterm birth in twin-to-twin transfusion syndrome treated with fetoscopic placental laser coagulation., Study Design: Prospective cohort study (n = 166) assessing cervical length (pre and postoperatively), amniotic fluid interleukin-6, serum C-reactive protein and duration of surgery. Logistic regression was used to investigate associations with preterm delivery., Results: Preterm delivery within 7 days, before 28.0 and 32.0 weeks occurred in 4.8%, 16.8%, and 28.9%, respectively. The only significant predictor of delivery within 7 days was postoperative cervical length (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.3-0.9). Concerning delivery before 32.0 weeks, preoperative cervical length (OR, 0.9; 95% CI, 0.8-1.0), and gestational age (OR, 0.8; 95% CI, 0.4-0.9) were independent risk factors but the association was weak. The presence of a single survivor after surgery was associated with a clear reduction of risk (OR, 0.3; 95% CI, 0.1-0.6). Inflammatory biomarkers and duration of surgery did not discriminate risk of prematurity., Conclusion: No strong preoperative predictive factor of preterm birth could be identified. A single survivor was a strong protective factor of very preterm birth., (Copyright © 2011 Mosby, Inc. All rights reserved.)

This pilot study investigated the possibility that metabolomic differences exist in second trimester of women delivering at term (≥37 weeks, n = 216) and preterm (≤35 weeks, n = 11). For this retrospective study, biobanked AF samples underwent near-infrared (NIR) spectral analysis using wavelengths from 700 to 1050 nm. Spectral data was compressed then optimized by multilinear regression to create a calibration model. The resultant model was able to classify term and preterm births based on differing AF metabolomic profiles with a sensitivity and specificity of 100%. When groups were classified using a prematurity index (PI), there was a statistical difference (P < 0.001) between the predicted preterm group (PI 0.77 ± 0.08) and the term group (PI 1.00 ± 0.02). In conclusion, the 2nd trimester AF samples showed distinct differences in metabolomic profiles between patients delivering preterm as compared to those at term in functional groups related to proteins, carbohydrates, fats, polyols, and water.

Objective: To determine the value of amniotic fluid interleukin-18 (AF IL-18) in the diagnosis of microbial invasion of the amniotic cavity and prediction of preterm delivery (PTD)., Design: Analysis of the results of AF collected prospectively following genetic amniocentesis between February 2006 and September 2007., Setting: A tertiary referral centre for fetal medicine., Methods: Following amniocentesis, a sample of amniotic fluid was transferred to the laboratory for aerobic and anaerobic bacterial cultures, Ureaplasma urealyticum culture and IL-18 assays. All women who delivered preterm (<37 weeks of gestation) formed the study group. The control group consisted of the two subsequent women who also underwent amniocentesis during the same time period and delivered a normal neonate at term, matched for maternal age, parity and indication for amniocentesis., Main Outcome Measures: The relationship between AF IL-18 levels and the risk of both microbial invasion of the amniotic cavity and PTD., Results: Forty-eight women who delivered preterm (<37 weeks) were matched with 96 controls. The preterm delivery group had significantly higher concentrations of IL-18 (median=609 pg/ml, interquartile range: 445.7-782.7) compared to controls (median=322.1 pg/ml, interquartile range: 277.7-414.4), (P<0.001). IL-18 level was also significantly higher (P<0.001) in cases with positive amniotic fluid cultures (median=697.7, interquartile range: 609.0-847.2) compared to those with negative ones (median=330.9 pg/ml, interquartile range: 235.2-440.8)., Conclusions: Elevated mid-trimester concentrations of AF IL-18 can identify women at risk for intraamniotic infection and spontaneous PTD.

Background: Adrenomedullin, secreted by decidua and trophoblast cells, is considered to participate in regulating uterine and placental blood flow, leading to control of placental hormonal secretion. Furthermore, adrenomedullin has an antimicrobial activity. The objective of this study was to determine whether adrenomedullin concentrations in midtrimester amniotic fluid can be used as a predictor of preterm delivery., Patients and Methods: Amniotic fluid samples were collected in a retrospective cross-matched study that included 362 women with singleton pregnancies who presented for genetic amniocentesis. Adrenomedullin concentrations were determined by ELISA in amniotic fluid taken from women with spontaneous preterm delivery (n=41) and maternal age-matched controls who had normal pregnancy at term (n=41)., Results: No difference was found in adrenomedullin concentrations between women with spontaneous preterm delivery (median: 1.33 ng/ml, range: 0.36-8.53 ng/ml) and controls (median: 1.32 ng/ml, range: 0.33-4.07 ng/ml), nor between a subset of cases of preterm premature rupture of membranes (n=19) and their controls (n=19)., Conclusion: Adrenomedullin concentration in amniotic fluid cannot serve as a predictor of preterm delivery.

Problem: The rate of pre-term birth in the United States continues to rise despite several interventions. Induction of pro-inflammatory cytokines and chemokines has been implicated in the activation of the cascade of events resulting in pre-term labor. To date, no comprehensive panel of the cytokine profile in PTL has been published., Method of Study: To address cytokine profiles in pre-term labor, levels of 19 plasma and amniotic fluid cytokines were measured using a multiplex immunoassay in an inflammation-induced murine model of pre-term labor., Results: Pro-inflammatory mediators, RANTES, KC, IL-6, and IL-12p40 were increased by 3 hr and remained high at 15 hr. Concentrations of KC, IL-6, IL-1beta, and MIP-1alpha were increased in the amniotic fluid at 15 hr. Plasma levels of anti-inflammatory mediators IL-10 and IL-13 at 15 hr were unchanged and decreased respectively., Conclusion: These results suggest that stimulation of several pro-inflammatory cytokines occurs very early in the cascade of events and remains increased, whereas anti-inflammatory cytokines are either unchanged or decreased until the onset of delivery in an inflammation-induced mouse model of pre-term labor.

Aims: To determine whether sonographic measurement of cervical length predicts intra-amniotic infection and impending preterm delivery (within 7 days of amniocentesis) in women with preterm labor and intact membranes, and to compare the predictability with that of amniotic fluid (AF) white blood cell (WBC) count., Methods: Transvaginal ultrasonographic assessment of cervical length was performed immediately after amniocentesis in 67 consecutive women with preterm labor. AF obtained by amniocentesis was cultured for aerobic and anaerobic bacteria and for Mycoplasmas, and WBC count was determined., Results: Patients with a positive AF culture had a significantly shorter median cervical length, higher median AF WBC count, and lower median gestational age at delivery than did those with a negative AF culture. Multivariate analysis indicated that only the AF WBC count bears a significant relationship with the presence of intra-amniotic infection, whereas only cervical length correlates with impending preterm delivery., Conclusions: Transvaginal sonographic measurements of cervical length are a valuable method for predicting intra-amniotic infection as well as impending preterm delivery in women with preterm labor. However, in comparison with AF WBC, cervical length is less predictive for intra-amniotic infection, whereas cervical length demonstrates better predictability of impending preterm delivery.

Intra-amniotic inflammation (IAI) may cause preterm birth with poor neonatal out-come. To identify novel biomarkers for IAI, we analyzed amniotic and cervical fluid samples from 27 patients with signs of threatening preterm birth with or without IAI by surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Seventeen proteins were significantly overexpressed in amniotic fluid from IAI cases and more often in women with preterm labor than those with rupture of membranes. Five of these were identified as human neutrophil protein 1-3, calgranulin A and B.

Objective: To investigate whether maternal serum and amniotic fluid CRP and PAPP-A concentrations at the time of genetic amniocentesis are markers of preterm delivery., Study Design: One hundred and forty-one pregnant women were included in this prospective study. Amniotic fluid and maternal serum CRP and PAPP-A concentrations were determined by using commercially available kits. Receiver-operating characteristic (ROC) analysis was performed to determine the efficacy of maternal serum and amniotic fluid CRP and PAPP-A levels in predicting women with preterm delivery., Results: The prevalence of spontaneous preterm delivery before 37 weeks of gestation was 9.9%. ROC analysis revealed that amniotic fluid CRP level was the only parameter, which had a significant power in the prediction of preterm delivery. The optimum cut-off level was 0.65 mg/L. The sensitivity and specificity were 92.9% and 78.7%, respectively., Conclusion: The amniotic fluid CRP level has a high sensitivity and specificity in the prediction of preterm delivery and this may be helpful in predicting preterm delivery during genetic amniocentesis.