Elevated second-trimester amniotic fluid interleukin-6 levels predict preterm delivery

The relationship of fetal sex and maternal race and ethnicity with early and late pregnancy C-reactive protein and interleukin-8

PROBLEM

Promotion of a healthy pregnancy is dependent on a coordinated immune response that minimizes inflammation at the maternal-fetal interface. Few studies investigated the effect of fetal sex on proinflammatory biomarkers during pregnancy and whether maternal race could impact this association. We aimed to examine whether fetal sex could, independently of maternal race/ethnicity and the condition of pregnancy (normal vs. complicated), impact inflammatory markers (C-reactive protein [CRP] and interleukin-8 [IL-8] levels) in early and late pregnancy.

METHODS OF STUDY

This study was a cohort analysis using prospectively collected data from pregnant women who participated in the Vitamin Antenatal Asthma Reduction Trial (VDAART, N = 816). Maternal serum CRP and IL-8 levels were measured in early and late pregnancy (10-18 and 32-38 weeks of gestation, respectively). Five hundred and twenty-eight out of 816 pregnant women who participated in the trial had available CRP and IL-8 measurements at both study time points. We examined the association of fetal sex with early and late CRP and IL-8 levels and their paired sample difference. We further investigated whether maternal race/ethnicity, pregnancy complications (i.e., preeclampsia and gestational diabetes), and early pregnancy body mass index (BMI) could affect the association between these two biomarkers and fetal sex adjusting for potential confounders. For this purpose, we used generalized linear and logistic regression models on log-normalized early and late CRP and IL-8 levels as well as their split at median to form high and low groups.

RESULTS

Women pregnant with male fetuses (266/528 = 56.5%) had higher CRP levels in early to mid-pregnancy (β = .18: 95% confidence interval [CI]: CI = 0.03-0.32; p = .02). Twenty-seven percent (143/528) of the study subjects were Hispanic. Hispanic African American [AA] women and women of races other than White and AA had higher levels of CRP at early to mid-pregnancy compared with White women (β = .57; 95% CI: 0.17-0.97; p < .01 and β = .27; 95% CI: 0.05-0.48; p = .02, respectively). IL-8 levels were not associated with fetal sex in early and late pregnancy (p's > .05). Other factors such as gestational diabetes and early pregnancy BMI were associated with higher CRP levels and higher CRP and IL-8 levels, respectively. Dichotomizing log-normalized cytokine levels at the median in a sensitivity analysis, women with male fetuses had lower odds of high (above-median) IL-8 levels at early pregnancy. Also, women with races other than AA and White carrying male fetuses had higher odds of having high (above-median) late-pregnancy CRP and early-pregnancy IL-8 levels (adjusted odds ratio [aOR] = 3.80, 95% CI: 0.24-1.23; p = .02 and aOR = 3.57; 95% CI: 0.23-1.03; p = .02, respectively). Of the pregnancy complications, women with gestational diabetes mellitus had a higher paired difference of early and late pregnancy CRP levels (β = .38; 95% CI: 0.09-0.68; p = .01), but no difference in IL-8 levels (p's > .05). No associations between the inflammatory markers and preeclampsia were found.

CONCLUSION

Fetal sex is associated with CRP in early pregnancy and an association with IL-8 in early pregnancy is implied. Our study further indicates that maternal race/ethnicity could be a contributing factor in the relationship between fetal sex and inflammatory responses during pregnancy. However, the specificity and level of the contribution might vary by type of cytokine, pregnancy stage, and other confounding factors such as BMI that may impact these associations.

The role of intraamniotic inflammation in threatened midtrimester miscarriage

BACKGROUND

The assessment and management of patients with threatened midtrimester miscarriage is a clinical challenge because the etiology of this condition is poorly understood.

OBJECTIVE

This study aimed to examine the frequency of intraamniotic infection or inflammation and the effect of antibiotics in patients presenting with regular uterine contractions and intact membranes before 20 weeks of gestation.

STUDY DESIGN

This retrospective study comprised patients who met the following criteria: (1) singleton gestation, (2) gestational age before 20 weeks, (3) the presence of regular uterine contractions confirmed by a tocodynamometer (8 or more contractions in 60 minutes), (4) intact amniotic membranes, and (5) transabdominal amniocentesis performed for the evaluation of the microbiologic and inflammatory status of the amniotic cavity. Samples of amniotic fluid were cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction was performed to detect Ureaplasma species. Amniotic fluid was tested for white blood cell counts and matrix metalloproteinase-8 concentrations to diagnose intraamniotic inflammation. Patients with intraamniotic inflammation, or intraamniotic infection, were treated with antibiotics (a combination of ceftriaxone, clarithromycin, and metronidazole). Treatment success was defined as the resolution of intraamniotic infection/inflammation at the follow-up amniocentesis or delivery after 34 weeks of gestation.

RESULTS

1) Intraamniotic inflammation was present in 88% (15/17) of patients, whereas infection was detectable in only 2 cases; 2) objective evidence of resolution of intraamniotic inflammation after antibiotic treatment was demonstrated in 100% (4/4) of patients who underwent a follow-up amniocentesis; 3) 30% (5/15) of women receiving antibiotics delivered after 34 weeks of gestation (3 of the 5 patients had a negative follow-up amniocentesis, and 2 of the women were without a follow-up amniocentesis); 4) the overall treatment success of antibiotics was 40% (6/15; 4 cases of objective evidence of resolution of intra-amniotic inflammation and 5 cases of delivery after 34 weeks of gestation).

CONCLUSION

The prevalence of intraamniotic inflammation in patients who presented with a threatened midtrimester miscarriage was 88% (15/17), and, in most cases, microorganisms could not be detected. Antibiotic treatment, administered to patients with intraamniotic inflammation, was associated with either objective resolution of intraamniotic inflammation or delivery after 34 weeks of gestation in 40% (6/15) of the cases.

Aberrant methylation of Serpine1 mediates lung injury in neonatal mice prenatally exposed to intrauterine inflammation

Background

Intrauterine inflammation (IUI) alters epigenetic modifications in offspring, leading to lung injury. However, the epigenetic mechanism underlying IUI-induced lung injury remains uncertain. In the present study, we aim to investigate the effect of IUI on lung development, and to identify the key molecule involved in this process and its epigenetic regulatory mechanism.

Results

Serpine1 was upregulated in the lung tissue of neonatal mice with IUI. Intranasal delivery of Serpine1 siRNA markedly reversed IUI-induced lung injury. Serpine1 overexpression substantially promoted cell senescence of both human and murine lung epithelial cells, reflected by decreased cell proliferation and increased senescence-associated β-galactosidase activity, G0/G1 cell fraction, senescence marker, and oxidative and DNA damage marker expression. IUI decreased the methylation level of the Serpine1 promoter, and methylation of the promoter led to transcriptional repression of Serpine1. Furthermore, IUI promoted the expression of Tet1 potentially through TNF-α, while Tet1 facilitated the demethylation of Serpine1 promoter. DNA pull-down and ChIP assays revealed that the Serpine1 promoter was regulated by Rela and Hdac2. DNA demethylation increased the recruitment of Rela to the Serpine1 promoter and induced the release of Hdac2.

Conclusion

Increased Serpine1 expression mediated by DNA demethylation causes lung injury in neonatal mice with IUI. Therefore, therapeutic interventions targeting Serpine1 may effectively prevent IUI-induced lung injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00901-8.

Expression of antimicrobial peptides in the amniotic fluid of women with cervical insufficiency

PROBLEM

Cervical insufficiency (CI) is associated with intra-amniotic infection or inflammation. Antimicrobial peptides (AMPs) in amniotic fluid may protect the fetus against microbial invasion, giving their broad-spectrum microbiocidal properties. We evaluated changes in amniotic fluid AMP expression in women with CI and assessed whether these changes are related to their pregnancy outcomes.

METHOD OF STUDY

We evaluated amniotic fluid human neutrophil peptide 3 (HNP-3), human β-defensin-2 (hBD-2), and LL-37 levels in 66 women with CI and 25 normal controls at 16-24 weeks of gestation. The CI group was divided into short cervix and cervical dilation groups, and the cervical dilation group was further divided into preterm and full-term delivery groups according to the pregnancy outcomes, and AMP expression was analyzed in each group.

RESULTS

HNP-3 and hBD-2 levels were higher in women with CI than in normal controls and in the cervical dilation as compared to the short cervix group. Among women with cervical dilation, 22 delivered at full-term, and 23 had spontaneous preterm births. The hBD-2 level in amniotic fluid mid-pregnancy was higher in the full-term delivery than in the preterm delivery groups. However, LL-37 levels in amniotic fluid were low in women with CI and normal controls.

CONCLUSIONS

Amniotic fluid HNP-3 and hBD-2 levels increased in women with CI compared with normal controls. Moreover, increased amniotic fluid hBD-2 levels mid-pregnancy were associated with favorable pregnancy outcomes in women with CI. AMPs in the amniotic fluid may participate in host defense against ascending infection in women with CI.

The amniotic fluid proteome predicts imminent preterm delivery in asymptomatic women with a short cervix

Preterm birth, the leading cause of perinatal morbidity and mortality, is associated with increased risk of short- and long-term adverse outcomes. For women identified as at risk for preterm birth attributable to a sonographic short cervix, the determination of imminent delivery is crucial for patient management. The current study aimed to identify amniotic fluid (AF) proteins that could predict imminent delivery in asymptomatic patients with a short cervix. This retrospective cohort study included women enrolled between May 2002 and September 2015 who were diagnosed with a sonographic short cervix (< 25 mm) at 16–32 weeks of gestation. Amniocenteses were performed to exclude intra-amniotic infection; none of the women included had clinical signs of infection or labor at the time of amniocentesis. An aptamer-based multiplex platform was used to profile 1310 AF proteins, and the differential protein abundance between women who delivered within two weeks from amniocentesis, and those who did not, was determined. The analysis included adjustment for quantitative cervical length and control of the false-positive rate at 10%. The area under the receiver operating characteristic curve was calculated to determine whether protein abundance in combination with cervical length improved the prediction of imminent preterm delivery as compared to cervical length alone. Of the 1,310 proteins profiled in AF, 17 were differentially abundant in women destined to deliver within two weeks of amniocentesis independently of the cervical length (adjusted p-value < 0.10). The decreased abundance of SNAP25 and the increased abundance of GPI, PTPN11, OLR1, ENO1, GAPDH, CHI3L1, RETN, CSF3, LCN2, CXCL1, CXCL8, PGLYRP1, LDHB, IL6, MMP8, and PRTN3 were associated with an increased risk of imminent delivery (odds ratio > 1.5 for each). The sensitivity at a 10% false-positive rate for the prediction of imminent delivery by a quantitative cervical length alone was 38%, yet it increased to 79% when combined with the abundance of four AF proteins (CXCL8, SNAP25, PTPN11, and MMP8). Neutrophil-mediated immunity, neutrophil activation, granulocyte activation, myeloid leukocyte activation, and myeloid leukocyte-mediated immunity were biological processes impacted by protein dysregulation in women destined to deliver within two weeks of diagnosis. The combination of AF protein abundance and quantitative cervical length improves prediction of the timing of delivery compared to cervical length alone, among women with a sonographic short cervix.

Composition of Vaginal Microbiota in Pregnant Women With Aerobic Vaginitis

Vaginal dysbiosis, such as bacterial vaginosis (BV) and aerobic vaginitis (AV), is an important cause of premature birth in pregnant women. However, there is very little research on vaginal microbial distribution in AV compared to that in BV. This study aimed to analyze the composition of the vaginal microbiota of pregnant women with AV using microbial community analysis and identify the causative organism using each criterion of the AV scoring system. Also, we compared the quantification of aerobic bacteria using quantitative polymerase chain reaction (qPCR) and their relative abundances (RA) using metagenomics. This prospective case–control study included 228 pregnant Korean women from our previous study. A wet mount test was conducted on 159 women to diagnose AV using the AV scoring system. Vaginal samples were analyzed using metagenomics, Gram staining for Nugent score determination, conventional culture, and qPCR for Staphylococcus spp., Streptococcus spp., and Enterobacteriaceae. The relative abundances (RAs) of eleven species showed significant differences among the three groups (Normal flora (NF), mild AV, and moderate AV). Three species including Lactobacillus crispatus were significantly lower in the AV groups than in the NF group, while eight species were higher in the AV groups, particularly moderate AV. The decrease in the RA of L. crispatus was common in three criteria of the AV scoring system (Lactobacillary, WBC, and background flora grades), while it did not show a significant difference among the three grade groups of the toxic leukocyte criterion. Also, the RAs of anaerobes, such as Gardnerella and Megasphaera, were higher in the AV groups, particularly moderate AV, while the RAs of aerobes were very low (RA < 0.01). Therefore, qPCR was performed for aerobes (Staphylococcus spp., Streptococcus spp., and Enterobacteriaceae); however, their quantification did not show a higher level in the AV groups when compared to that in the NF group. Therefore, AV might be affected by the RA of Lactobacillus spp. and the main anaerobes, such as Gardnerella spp. Activation of leukocytes under specific conditions might convert them to toxic leukocytes, despite high levels of L. crispatus. Thus, the pathogenesis of AV can be evaluated under such conditions.

Inflammatory Amplification: A Central Tenet of Uterine Transition for Labor

In preparation for delivery, the uterus transitions from actively maintaining quiescence during pregnancy to an active parturient state. This transition occurs as a result of the accumulation of pro-inflammatory signals which are amplified by positive feedback interactions involving paracrine and autocrine signaling at the level of each intrauterine cell and tissue. The amplification events occur in parallel until they reach a certain threshold, ‘tipping the scale’ and contributing to processes of uterine activation and functional progesterone withdrawal. The described signaling interactions all occur upstream from the presentation of clinical labor symptoms. In this review, we will: 1) describe the different physiological processes involved in uterine transition for each intrauterine tissue; 2) compare and contrast the current models of labor initiation; 3) introduce innovative models for measuring paracrine inflammatory interactions; and 4) discuss the therapeutic value in identifying and targeting key players in this crucial event for preterm birth.

AACC Guidance Document on Laboratory Testing for the Assessment of Preterm Delivery

Identifying women with preterm labor who will go on to deliver prematurely is crucial to improving outcomes for mother and baby and for saving healthcare resources. Even among those with symptoms, the number of women who deliver preterm is low, and thus the low positive predictive value (PPV) and high negative predictive value (NPV) associated with available biomarkers does not substantially reduce the uncertainty of the clinical diagnosis. While there is some promise in the use of fetal fibronectin (fFN), interleukin 6 (IL-6), or placental alpha microglobulin 1 (PAMG-1) for predicting preterm birth (PTB), their use is unlikely to provide considerable clinical value in populations with a low prevalence. To provide real clinical benefit, a biomarker must demonstrate a high PPV to allow identification of the minority of symptomatic women who will deliver prematurely. As none of the currently available biomarkers exhibit this performance characteristic, we do not recommend their routine clinical use in populations with a pre-test probability of PTB of <5%. Limiting biomarker testing to only high-risk women identified on the basis of cervical length or other characteristics will increase the pre-testprobability in the tested population, thereby improving PPV. PAMG-1 is associated with a higher PPV than fFN and may show clinical utility in populations with a higher pre-test probability, but further work is required to conclusively demonstrate improved outcomes in this patient group.

Melatonin for the prevention of fetal injury associated with intrauterine inflammation

Intrauterine inflammation is shown to be associated with preterm birth, fetal inflammatory response syndrome, and other pregnancy-related comorbidities such as central nervous system diseases including cerebral palsy and periventricular leukomalacia, pulmonary diseases such as bronchopulmonary dysplasia and respiratory distress syndrome, and necrotizing enterocolitis, to name a few. Many animal studies on intrauterine inflammation demonstrate that ascending infection of reproductive organs or the production of proinflammatory cytokines by some stimuli in utero results in such manifestations. Melatonin, known for its primary function in maintaining circadian rhythm, is now recognized as one of the most potent antioxidant and anti-inflammatory drugs. In some studies, melatonin injection in pregnant animals with intrauterine inflammation significantly reduced the number of preterm births, the severity of structural disintegration of the fetal lungs observed in bronchopulmonary dysplasia, and perinatal brain injuries with improvement in neuromotor function. These implicated benefits of melatonin in pregnant women with intrauterine inflammation seem promising in many research studies, strongly supporting the hypothesis that melatonin has antioxidative and anti-inflammatory properties that can potentially be taken by pregnant women who are at risk of having intrauterine inflammation. In this review, the potential of melatonin for improving outcomes of the pregnancies with intrauterine inflammation will be discussed.

Dirty Fish Versus Squeaky Clean Mice: Dissecting Interspecies Differences Between Animal Models of Interferonopathy

Autoimmune and autoinflammatory diseases are rare but often devastating disorders, underpinned by abnormal immune function. While some autoimmune disorders are thought to be triggered by a burden of infection throughout life, others are thought to be genetic in origin. Among these heritable disorders are the type I interferonopathies, including the rare Mendelian childhood-onset encephalitis Aicardi-Goutières syndrome. Patients with Aicardi Goutières syndrome are born with defects in enzymes responsible for nucleic acid metabolism and develop devastating white matter abnormalities resembling congenital cytomegalovirus brain infection. In some cases, common infections preceded the onset of the disease, suggesting immune stimulation as a potential trigger. Thus, the antiviral immune response has been actively studied in an attempt to provide clues on the pathological mechanisms and inform on the development of therapies. Animal models have been fundamental in deciphering biological mechanisms in human health and disease. Multiple rodent and zebrafish models are available to study type I interferonopathies, which have advanced our understanding of the human disease by identifying key pathological pathways and cellular drivers. However, striking differences in phenotype have also emerged between these vertebrate models, with zebrafish models recapitulating key features of the human neuropathology often lacking in rodents. In this review, we compare rodent and zebrafish models, and summarize how they have advanced our understanding of the pathological mechanisms in Aicardi Goutières syndrome and similar disorders. We highlight recent discoveries on the impact of laboratory environments on immune stimulation and how this may inform the differences in pathological severity between mouse and zebrafish models of type I interferonopathies. Understanding how these differences arise will inform the improvement of animal disease modeling to accelerate progress in the development of therapies for these devastating childhood disorders.

Protein Concentrations of Thrombospondin-1, MIP-1β, and S100A8 Suggest the Reflection of a Pregnancy Clock in Mid-Trimester Amniotic Fluid

The development of immunoassays enables more sophisticated studies of the associations between protein concentrations and pregnancy outcomes, allowing early biomarker identification that can improve neonatal outcomes. The aim of this study was to explore associations between selected mid-trimester amniotic fluid proteins and (1) overall gestational duration and (2) spontaneous preterm delivery. A prospective cohort study, including women undergoing mid-trimester transabdominal genetic amniocentesis, was performed in Gothenburg, Sweden, 2008-2016 (n = 1072). A panel of 27 proteins related to inflammation was analyzed using Meso-Scale multiplex technology. Concentrations were adjusted for gestational age at sampling, experimental factors, year of sampling, and covariates (maternal age at sampling, parity (nulliparous/multiparous), smoking at first prenatal visit, and in vitro fertilization). Cox regression analysis of the entire cohort was performed to explore possible associations between protein concentrations and gestational duration. This was followed by Cox regression analysis censored at 259 days or longer, to investigate whether associations were detectable in women with spontaneous preterm delivery (n = 47). Finally, linear regression models were performed to analyze associations between protein concentrations and gestational duration in women with spontaneous onset of labor at term (n = 784). HMG-1, IGFBP-1, IL-18, MIP-1α, MIP-1β, S100A8, and thrombospondin-1 were significantly associated with gestational duration at term, but not preterm. Increased concentrations of thrombospondin-1, MIP-1β, and S100A8, respectively, were significantly associated with decreased gestational duration after the Holm-Bonferroni correction in women with spontaneous onset of labor at term. This adds to the concept of a pregnancy clock, where our findings suggest that such a clock is also reflected in the amniotic fluid at early mid-trimester, but further research is needed to confirm this.

Evidence that antibiotic administration is effective in the treatment of a subset of patients with intra-amniotic infection/inflammation presenting with cervical insufficiency

BACKGROUND

Cervical insufficiency is a risk factor for spontaneous midtrimester abortion or early preterm birth. Intra-amniotic infection has been reported in 8-52% of such patients and intra-amniotic inflammation in 81%. Some professional organizations have recommended perioperative antibiotic treatment when emergency cervical cerclage is performed. The use of prophylactic antibiotics is predicated largely on the basis that they reduce the rate of complications during the course of vaginal surgery. However, it is possible that antibiotic administration can also eradicate intra-amniotic infection/inflammation and improve pregnancy outcome.

OBJECTIVE

To describe the outcome of antibiotic treatment in patients with cervical insufficiency and intra-amniotic infection/inflammation.

STUDY DESIGN

The study population consisted of 22 women who met the following criteria: (1) singleton pregnancy; (2) painless cervical dilatation of >1 cm between 16.0 and 27.9 weeks of gestation; (3) intact membranes and absence of uterine contractions; (4) transabdominal amniocentesis performed for the evaluation of the microbiologic and inflammatory status of the amniotic cavity; (5) presence of intra-amniotic infection/inflammation; and (6) antibiotic treatment (regimen consisted of ceftriaxone, clarithromycin, and metronidazole). Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction for Ureaplasma spp. was performed. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms or a positive polymerase chain reaction for Ureaplasma spp., and intra-amniotic inflammation was suspected when there was an elevated amniotic fluid white blood cell count (≥19 cells/mm³) or a positive rapid test for metalloproteinase-8 (sensitivity 10 ng/mL). For the purpose of this study, the "gold standard" for diagnosis of intra-amniotic inflammation was an elevated interleukin-6 concentration (>2.6 ng/mL) using an enzyme-linked immunosorbent assay. The results of amniotic fluid interleukin-6 were not available to managing clinicians. Follow-up amniocentesis was routinely offered to monitor the microbiologic and inflammatory status of the amniotic cavity and fetal lung maturity. Treatment success was defined as resolution of intra-amniotic infection/inflammation or delivery ≥34 weeks of gestation.

RESULTS

Of 22 patients with cervical insufficiency and intra-amniotic infection/inflammation, 3 (14%) had microorganisms in the amniotic fluid. Of the 22 patients, 6 (27%) delivered within 1 week of amniocentesis and the remaining 16 (73%) delivered more than 1 week after the diagnostic procedure. Among these, 12 had a repeat amniocentesis to assess the microbial and inflammatory status of the amniotic cavity; in 75% (9/12), there was objective evidence of resolution of intra-amniotic inflammation or intra-amniotic infection demonstrated by analysis of amniotic fluid at the time of the repeat amniocentesis. Of the 4 patients who did not have a follow-up amniocentesis, all delivered ≥34 weeks, 2 of them at term; thus, treatment success occurred in 59% (13/22) of cases.

CONCLUSION

In patients with cervical insufficiency and intra-amniotic infection/inflammation, administration of antibiotics (ceftriaxone, clarithromycin, and metronidazole) was followed by resolution of the intra-amniotic inflammatory process or intra-amniotic infection in 75% of patients and was associated with treatment success in about 60% of cases.

Effects of consuming sugars and alternative sweeteners during pregnancy on maternal and child health: evidence for a secondhand sugar effect

Consumption of sugar and alternative low- or no-energy sweeteners has increased in recent decades. However, it is still uncertain how consumption of sugar and alternative sweeteners during pregnancy affects pregnancy outcomes and long-term offspring health. This review aims to collate the available evidence surrounding the consequences of sugar and alternative sweetener consumption during pregnancy, a so-called secondhand sugar effect. We found evidence that sugar consumption during pregnancy may contribute to increased gestational weight gain and the development of pregnancy complications, including gestational diabetes, preeclampsia and preterm birth. Further, we found a growing body of the animal and human evidence that maternal sugar intake during pregnancy may impact neonatal and childhood metabolism, taste perception and obesity risk. Emerging evidence also suggests that both maternal and paternal preconception sugar intakes are linked to offspring metabolic outcomes, perhaps via epigenetic alterations to the germline. While there have been fewer studies of the impacts of alternative sweetener consumption before and during pregnancy, there is some evidence to suggest effects on infant outcomes including preterm birth risk, increased infant body composition and offspring preference for sweet foods, although mechanisms are unclear. We conclude that preconception and gestational sugar and alternative sweetener consumption may negatively impact pregnancy outcomes and offspring health and that there is a need for further observational, mechanistic and intervention research in this area.

Association of a placental Interleukin-6 genetic variant (rs1800796) with DNA methylation, gene expression and risk of acute chorioamnionitis

BACKGROUND

Acute chorioamnionitis (aCA), inflammation of the placenta and fetal membranes, is a frequently reported lesion in preterm deliveries. Genetic variants in innate immune system genes such as Interleukin-6 (IL6) may contribute to the placenta's inflammatory response, thus predisposing some pregnancies to aCA. These genetic variants may modulate molecular processes such as DNA methylation and gene expression, and in turn might affect susceptibility to aCA. Currently, there is remarkably little research on the role of fetal (placental) genetic variation in aCA. We aimed to explore the associations between genetic variants in candidate immune-system genes and susceptibility towards inflammatory responses in the placenta, which is linked to a strong inflammatory response in the newborn.

METHODS

DNA samples from 269 placentas (72 aCA cases, 197 non-aCA cases) were collected for this study. Samples were genotyped at 55 ancestry informative markers (AIMs) and 16 additional single nucleotide polymorphisms (SNPs) in 12 candidate innate immune system genes using the Sequenom iPLEX Gold Assay. Publicly available datasets were used to obtain DNA methylation (GSE100197, GSE74738, GSE115508, GSE44667, GSE98224) and gene expression data (GSE44711, GSE98224).

RESULTS

Differences in IL6 placental allele frequencies were associated with aCA (rs1800796, p = 0.04) with the CC genotype specifically implicated (OR = 3.1; p = 0.02). In a subset of the placental samples (n = 67; chorionic villi), we showed that the IL6 SNP (rs1800796) was associated with differential DNA methylation in five IL6-related CpG sites (cg01770232, cg02335517, cg07998387, cg13104385, and cg0526589), where individuals with a CC genotype showed higher DNA methylation levels than individuals carrying the GG genotype. Using two publicly available datasets, we observed that the DNA methylation levels at cg01770232 negatively correlated with IL6 gene expression in the placenta (r = - 0.67, p < 0.004; r = - 0.56, p < 2.937e-05).

CONCLUSIONS

We demonstrated that the minor C allele at the IL6 SNP (rs1800796), which is largely limited to East Asian populations, is associated with the presence of aCA. This SNP was associated with increased DNA methylation at a nearby MEPC2 binding site, which was also associated with decreased expression of IL6 in the placenta. Decreased expression of IL6 may increase vulnerability to microbial infection. Additional studies are required to confirm this association in Asian populations with larger sample sizes.

The association between selected mid-trimester amniotic fluid candidate proteins and spontaneous preterm delivery

Objective: The aim of this study was to explore inflammatory response and identify early potential biomarkers in mid-trimester amniotic fluid associated with subsequent spontaneous preterm delivery (PTD).Methods: A cohort study was performed at Sahlgrenska University Hospital/Östra, Gothenburg, Sweden, between 2008 and 2010. Amniotic fluid was collected from consecutive women undergoing mid-trimester transabdominal genetic amniocentesis at 14-19 gestational weeks. Clinical data and delivery outcome variables were obtained from medical records. The analysis included 19 women with spontaneous PTD and 118 women who delivered at term. A panel of 26 candidate proteins was analyzed using Luminex xMAP technology. Candidate protein concentrations were analyzed with ANCOVA and adjusted for plate effects.Results: The median gestational age at delivery was 35 + 3 weeks in women with spontaneous PTD and 40 + 0 weeks in women who delivered at term. Nominally significantly lower amniotic fluid levels of adiponectin (PTD: median 130,695 pg/mL (IQR 71,852-199,414) vs term: median 185,329 pg/mL (IQR (135,815-290,532)), granulocyte-macrophage colony stimulating factor (PTD: median 137 pg/mL (IQR 74-156) vs term: median 176 pg/mL (IQR 111-262)), and macrophage migration inhibitory factor (PTD: median 3025 pg/mL (IQR 1885-3891) vs term: median 3400 pg/mL (IQR 2181-5231)) were observed in the spontaneous PTD group, compared with the term delivery group, after adjusting for plate effects. No significant differences remained after Bonferroni correction for multiple comparisons.Conclusions: Our results are important in the process of determining the etiology behind spontaneous PTD but due to the non-significance after Bonferroni correction, the results should be interpreted with caution. Further analyses of larger sample size will be required to determine whether these results are cogent and to examine whether microbial invasion of the amniotic cavity or intra-amniotic inflammation occurs in asymptomatic women in the mid-trimester with subsequent spontaneous PTD.

Maternal blood endotoxin activity in pregnancies complicated by preterm premature rupture of membranes

Objective: To compare maternal blood endotoxin activity (EA) in women with preterm premature rupture of membranes (PPROM) with gestational age (GA) matched controls; to evaluate serial EA till birth in PPROM and its correlation with latency to delivery. Methods: We followed singleton preterm pregnancies from admission with PPROM until birth. Uncomplicated, GA-matched pregnancies served as controls. Demographics, birth and neonatal outcomes were collected. EA (EAA™) was assessed serially in PPROM and at study entry in controls. EA was compared using Mann Whitney and Wilcoxon tests, p value <.05 was considered significant. Results: We recruited 20 cases of PPROM and 20 controls. Demographics were similar between groups. Mean GA of PPROM was 29.0 ± 2.2 weeks and median latency was 7.5 (IQR 14.1) weeks. Median EA at admission following PPROM was significantly elevated over controls (0.43 (0.18) versus 0.36 (0.2); p < .02). Overall there was no difference in median EA at admission and in labor (0.43 (0.18) versus 0.33 (0.21); p = .2) following PPROM. However, on comparing cases with latency to delivery ≤7 days (n = 10) versus >7 days (n = 10), there was a significant drop in EA in the latter group (0.44 (0.2) versus 0.34 (0.2); p < .004). Conclusions: EA in PPROM represents a promising biomarker in predicting the clinical evolution of preterm birth.

Fusobacterium nucleatum and adverse pregnancy outcomes: Epidemiological and mechanistic evidence

Fusobacterium nucleatum is a Gram-negative anaerobic oral commensal associated with periodontal disease. F. nucleatum has been implicated in a wide spectrum of systemic diseases, including oral, gastro-intestinal, rheumatologic, and vascular pathologies. As pregnancy risk has been linked to periodontal disease, there has also been significant research into the effects of periodontal disease on adverse pregnancy outcomes. This article reviews the epidemiological and mechanistic evidence of the role of F. nucleatum in adverse pregnancy outcomes.

Maternal Hepatitis B Virus Infection and Pregnancy Outcomes: A Hospital-based Case-control Study in Wuhan, China

GOALS

To examine the impact of maternal hepatitis B virus infection on pregnancy outcomes.

BACKGROUND

Studies regarding hepatitis B virus infection and pregnancy outcomes are limited with inconsistent results, and none of them have evaluated the effect of maternal viral load in pregnancy on pregnancy outcomes.

STUDY

A hospital-based case-control study was conducted. In total, 1728 hepatitis B surface antigen (HBsAg)-positive women who delivered consecutively at Wuhan Women and Children Medical and Healthcare Center, Wuhan, China, from June 2008 to May 2015, were compared with 1497 HBsAg-negative women giving birth in the same hospital during the same period who were randomly identified and selected from the computerized medical record database in parallel. Univariate and multivariate logistic regression models were constructed.

RESULTS

After adjusting for confounding variables, maternal HBsAg carriage was associated with increased risk of pregnancy-induced hypertension [adjusted odds ratio (aOR)=2.20; 95% confidence interval (CI), 1.30-3.73], fetal distress (aOR=1.40; 95% CI, 1.09-1.78), cesarean delivery (aOR=1.70; 95% CI, 1.45-1.99), and macrosomia (aOR=1.68; 95% CI, 1.19-2.37). Moreover, maternal viral load in the second trimester was significantly associated with risk of preterm birth (aOR for each log10 copy/mL increase, 1.18; 95% CI, 1.01-1.39) among HBsAg carriers after adjustment for maternal age, employment, parity, history of abortion, and prenatal body mass index.

CONCLUSIONS

Maternal HBsAg carriage was associated with several adverse pregnancy outcomes. Furthermore, hepatitis B viral activity in pregnancy might have certain effects on pregnancy outcomes. Careful surveillance of maternal HBsAg status as well as viral activity in the second trimester among HBsAg carriers is warranted.

Comparison of rapid MMP-8 and interleukin-6 point-of-care tests to identify intra-amniotic inflammation/infection and impending preterm delivery in patients with preterm labor and intact membranes. J Matern Fetal Neonatal Med 2018;31:228-244. [PMID: 28081646 PMCID: PMC5769687 DOI: 10.1080/14767058.2017.1281904]

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

(1) The rapid tests had the same sensitivity for the detection of intra-amniotic inflammation [85.7% (18/21) for all]; (2) the specificity of the rapid MMP-8 test was higher than that of the rapid IL-6 test (cutoff: 745 pg/mL) for the identification of intra-amniotic inflammation [72.8% (75/103) vs. 64.1% (66/103); p < 0.05]; and (3) there were no differences in the sensitivity and specificity between the rapid MMP-8 test and the rapid IL-6 test (cutoff:1000 pg/mL) in the identification of intra-amniotic inflammation. Of 13 patients with discrepant results between the rapid MMP-8 and rapid IL-6 tests, two had a positive MMP-8 but a negative rapid IL-6 test, and both delivered preterm - one within 24 h, and the other within 10 days - and both had acute histologic chorioamnionitis. On the other hand, there were 11 patients with a positive rapid IL-6 but a negative rapid MMP-8 result: 10 delivered preterm, 3 had acute histologic chorioamnionitis and 1 had subacute chorionitis.

CONCLUSION

We conclude that the rapid MMP-8 test has a better specificity than the rapid IL-6 (cutoff: 745 pg/mL) assay for the detection of intra-amniotic infection. Moreover, we observed that among patients who were not identified as having intra-amniotic infection or inflammation by the standard cultivation technique and amniotic fluid WBC count, those who had a positive MMP-8 rapid test delivered preterm and had acute histologic chorioamnionitis.

The diagnostic performance of the beta-glucan assay in the detection of intra-amniotic infection with Candida species

INTRODUCTION

A bioassay based on the detection of beta-glucan, a constituent of the cell wall of fungi, has been successfully used to diagnose fungal infections in a variety of biological fluids but not yet in the amniotic fluid.

OBJECTIVE

To determine the diagnostic performance of a beta-glucan bioassay in the detection of Candida species in the amniotic fluid of women who either did or did not have an intrauterine contraceptive device (IUD) in place during an episode of spontaneous preterm parturition.

METHODS

The study population comprised women who had a singleton pregnancy without congenital or chromosomal abnormalities, who experienced preterm labor or preterm prelabor rupture of the fetal membranes, and who underwent a transabdominal amniocentesis for clinical indications. Samples of amniotic fluid were cultured for aerobic and anaerobic bacteria, genital mycoplasmas, and Candida species, and assayed for beta-glucan, using the (1→3)-beta-d-glucan-specific Limulus amebocyte lysate test (beta-glucan assay) in all cases. Amniotic fluid interleukin (IL)-6 assay results were also available for all cases. The beta-glucan assay takes about 1 hour to run: a concentration >80 pg/mL was considered positive for fungi. Sterile intra-amniotic inflammation of the amniotic cavity was defined by the presence of an amniotic fluid IL-6 concentration ≥2.6 ng/mL and a negative amniotic fluid culture.

RESULTS

(1) One hundred ninety-seven (197) women met the study criteria, of whom 58 (29.4%) had an IUD in place; (2) 20 (10.2%) women had a culture of proven intra-amniotic Candida species-related infection, 19 of whom had a positive beta-glucan assay [sensitivity, 95% (19/20; 95% confidence interval (CI): 75.1-99.9%)]; and (3) the specificity of the beta-glucan assay was 75.1% [133/177; 95% CI: 68.1-99.9%]. It was affected by the presence of nonfungal intra-amniotic infections and an IUD, but not by the presence of sterile intra-amniotic inflammation, and there was a significant interaction between the presence of an IUD and nonfungal intra-amniotic infections (estimated for the interaction effect = 2.1923, p value =.026). The assay's specificity was reduced when nonfungal intra-amniotic infections were diagnosed but only in women who did not have an IUD. Among women without an IUD, the assay's specificity was 91.4% (117/128); it was 93% (106/114) for those without intra-amniotic infection, and 78.6% (11/14) for those with a nonfungal intra-amniotic infection; the difference was not significant (p = .09). Among women with an IUD, the assay's specificity was 32.7% (16/49); 42.9% (9/21) for those with a nonfungal intra-amniotic infection; and 25% (7/28) for those without intra-amniotic infection; and the difference was significant (p = .03).

CONCLUSIONS

The beta-glucan assay is a sensitive, rapid, point-of-care test used to diagnose intra-amniotic Candida species-related infection, and it has a high specificity in pregnant women who did not have an IUD in place.

Early- or mid-trimester amniocentesis biomarkers for predicting preterm delivery: a meta-analysis

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.

Role of Cervical Length Measurement for Preterm Delivery Prediction in Women With Threatened Preterm Labor and Cervical Dilatation

OBJECTIVES

To compare the accuracy and cutoff points for cervical length for predicting preterm delivery in women with threatened preterm labor between those with a closed cervix and cervical dilatation.

METHODS

We conducted a retrospective cohort study of women with singleton pregnancies with threatened preterm labor before 34 weeks. The accuracy of cervical length for predicting preterm delivery was compared between women with cervical dilatation (0.5-3 cm) and those with a closed cervix. The predictive accuracy of cervical length for spontaneous preterm delivery was analyzed with several outcome-specific thresholds.

RESULTS

Overall, 1068 women with threatened preterm labor met the inclusion criteria; of them, 276 (25.8%) had cervical dilatation, and 792 (74.2%) had a closed cervix. The risk of preterm delivery before 37 weeks was significantly higher in the cervical dilatation group than the closed cervix group, as well as a shorter assessment-to-delivery interval of within 14 days (P = .001 and .004, respectively). On a multivariable analysis, cervical length was independently associated with the risk of preterm delivery in both groups. There was no significant difference between women with cervical dilatation and those with a closed cervix regarding the area under the receiver operating characteristic curves of cervical length for prediction of preterm delivery before 37 (0.674 versus 0.618; P = .18) and 34 (0.628 versus 0.640; P = .88) weeks and an assessment-to-delivery interval of 14 days (0.686 versus 0.660; P= .72). The negative predictive value of cervical length ranged from 77.4% to 95.7% depending on the different thresholds used.

CONCLUSIONS

Cervical length was significantly associated with the risk of preterm delivery in women presenting with threatened preterm labor and cervical dilatation of less than 3 cm. However, the predictive accuracy of cervical length as a single measure was relatively limited.

Thrombin-Induced Inflammation in Human Decidual Cells Is Not Affected By Heparin

OBJECTIVE

Thrombin (Thr) generation at the uteroplacental interface induces inflammation and weakens fetal membranes. Tissue factor (TF) is a powerful procoagulant that is increased by Thr in decidual cells (DCs). The TF expression may play an important role in modulating Thr-induced inflammation. The purpose of this study was to assess the effect of heparin, including nonanticoagulant (desulfated) heparins, on basal and Thr-induced expression of TF and inflammatory cytokines in DCs.

METHODS

Fetal membranes were collected from term pregnancies undergoing unlabored cesarean delivery and then DCs were isolated and cultured. Third passage DCs were conditioned in defined media for 1 week and then treated with 1 of the 4 heparins (enoxaparin, unfractionated heparin, and 2 desulfated heparins) with and without Thr (2.5 U/mL) for 24 hours. Supernatant levels of interleukin (IL) 6, IL-8, IL-10, tumor necrosis factor α, and interferon γ (IFN-γ) were determined by enzyme-linked immunosorbent assay. Western blots were performed on cell lysates to determine TF expression. A Kruskal-Wallis test was used to compare cytokine concentrations and normalized TF expression among treatments.

RESULTS

Treatment of DCs with Thr alone increased the expression of TF, IL-6, IL8, IL-10, and IFN-γ compared to basal levels ( P < .05 for each). Cotreatment of DCs with Thr and any of the tested heparins did not decrease the expression of TF or inflammatory cytokines compared to treatment with Thr alone.

DISCUSSION

Heparins do not appear to affect basal or Thr-induced expression of TF or inflammatory cytokines in human term DCs. Additional work is needed to determine whether nonanticoagulant heparins can reduce inflammation and membrane weakening due to bleeding in pregnancy.

Associations Among Child Abuse, Depression, and Interleukin-6 in Pregnant Adolescents: Paradoxical Findings

OBJECTIVE

Limited data exist on child abuse-related immune variation during pregnancy, despite implications for maternal and infant health and extensive data showing that abuse history and depression are related to increased inflammation in other populations. This study examined associations among child abuse, depression, circulating levels of inflammatory markers, and perinatal health in pregnant adolescents, a group at high risk for childhood abuse and poor birth outcomes.

METHODS

Pregnant teenagers (n = 133; 14-19 years; 89.5% Latina) reported on abuse and depression and had two blood draws (24-27 and 34-37 gestational weeks, second and third trimesters, respectively) for interleukin-6 (IL-6) and C-reactive protein; birth outcomes were collected.

RESULTS

Abuse and depression interacted to predict higher IL-6 at second trimester (B = 0.006, p = .011) such that severely abused adolescents with high depression had higher IL-6 relative to severely abused adolescents with low depression; depression did not differentiate IL-6 levels for those with low abuse severity. Abuse and IL-6 also interacted to predict gestational age at birth (B = 0.004, p = .040) such that those with low abuse and high IL-6 and those with high abuse and low IL-6 had infants with earlier gestational age at birth. Cortisol at the second trimester mediated the association between IL-6 and gestational age at birth (indirect effect estimate=-0.143, p < .039).

CONCLUSIONS

Depression severity distinguished IL-6 levels among more severely abused pregnant Latina adolescents, but it was unrelated to IL-6 among less severely abused adolescents. Cortisol explained the relationship between IL-6 and earlier gestational age at birth. Multiple adversities and inflammation may influence birth outcomes and potentially affect intergenerational health.

Genetic variation associated with preterm birth in African-American women

BACKGROUND

Preterm birth is considered a multifactorial condition; however, emerging evidence suggests that genetic variation among individuals may have an important role. Prior studies have suggested that single-nucleotide polymorphisms associated with genes related to the immune system, and particularly the maternal inflammatory response, may be associated with an increased risk of preterm delivery.

OBJECTIVE

The objective of the study was to identify single-nucleotide polymorphisms associated with spontaneous preterm birth <37 weeks within a cohort of African-American women.

STUDY DESIGN

This is a secondary analysis of a randomized trial that evaluated periodontal disease and preterm birth. Women were enrolled between 6 and 20 weeks' gestation at 3 prenatal care clinics between 2004 and 2007. Maternal DNA samples were collected and analyzed using a custom 1536 single-nucleotide polymorphismgenotyping array designed to assess genes involved in inflammation. Women were included in this study if they self-identified as African American. We excluded women with a multiple gestation or an indicated preterm delivery. We performed allele- and genotype-based analyses to evaluate the association between spontaneous preterm birth and tag single-nucleotide polymorphisms. We used a logistic regression to adjust for prior preterm birth in our genotype-based analysis. In a subgroup analysis, we compared women who delivered at <34 weeks' gestation to women who delivered at term. Within the microarray, we identified ancestry informative markers and compared global ancestry estimates among women who delivered preterm with those who delivered at term.

RESULTS

Of the 833 African-American women in the study with genotype data, 77 women (9.2%) had a spontaneous preterm birth, whereas 756 women delivered at term. In an allele-based analysis, 4 single-nucleotide polymorphisms related to the genes for protein kinase C-α (PRKCA) were associated with increased risk of spontaneous preterm birth <37 weeks, whereas a single single-nucleotide polymorphism related to fms-related tyrosine kinase 1 (FLT1) was associated with spontaneous preterm birth <34 weeks. A genotype-based analysis revealed similar associations between single-nucleotide polymorphisms related to the PRKCA genes and spontaneous premature delivery. Additionally, single-nucleotide polymorphisms related to matrix metalloproteinase-2 (MMP2), tissue inhibitor of matrix metalloproteinase-2 (TIMP2), and interleukin 16 (IL16) genes were associated with spontaneous preterm birth <37 weeks in genotype-based analysis. Genetic variants related to MMP2, matrix metalloproteinase-1 (MMP1), and leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) genes were associated with higher rates of preterm birth <34 weeks. Ancestry estimates were similar between the women who had a spontaneous preterm birth and those who delivered at term.

CONCLUSION

We identified tag single-nucleotide polymorphisms related to 7 genes that are critical to inflammation, extracellular remodeling, and cell signaling that were associated with spontaneous preterm birth in African-American women. Specifically, we found a strong association with the PRKCA gene. Genetic variation in these regions of the genome may be important in the pathogenesis of preterm birth. Our results should be considered in the design of future genomic studies in prematurity.

The effects of periodontal treatment on pregnancy outcomes

BACKGROUND

Preterm infants are at greater risk than term infants for physical and developmental disorders. Morbidity and mortality increases as gestational age at delivery decreases. Observational studies indicate an association between poor periodontal health and risk for preterm birth or low birthweight, making periodontitis a potentially modifiable risk factor for prematurity.

AIM

To identify randomized controlled trials (RCTs) published between January 2011 and July 2012 and discuss all published RCTs testing whether periodontal therapy reduces rates of preterm birth and low birthweight.

METHODS

Search of databases including PubMed, ISI Web of Science and Cochrane Library.

RESULTS

The single RCT identified showed no significant effect of periodontal treatment on birth outcomes.

DISCUSSION

All published trials included non-surgical periodontal therapy; only two included systemic antimicrobials as part of test therapy. The trials varied substantially in terms of sample size, obstetric histories of subjects, study preterm birth rates and the periodontal treatment response. The largest trials--also judged to be high-quality and at low risk of bias--have yielded consistent results, and indicate that treatment does not alter rates of adverse pregnancy outcomes.

CONCLUSION

Non-surgical periodontal therapy, scaling and root planing, does not improve birth outcomes in pregnant women with periodontitis.

The effects of periodontal treatment on pregnancy outcomes

BACKGROUND

Preterm infants are at greater risk than term infants for physical and developmental disorders. Morbidity and mortality increases as gestational age at delivery decreases. Observational studies indicate an association between poor periodontal health and risk for preterm birth or low birthweight, making periodontitis a potentially modifiable risk factor for prematurity.

AIM

To identify randomized controlled trials (RCTs) published between January 2011 and July 2012 and discuss all published RCTs testing whether periodontal therapy reduces rates of preterm birth and low birthweight.

METHODS

Search of databases including PubMed, ISI Web of Science and Cochrane Library.

RESULTS

The single RCT identified showed no significant effect of periodontal treatment on birth outcomes.

DISCUSSION

All published trials included non-surgical periodontal therapy; only two included systemic antimicrobials as part of test therapy. The trials varied substantially in terms of sample size, obstetric histories of subjects, study preterm birth rates and the periodontal treatment response. The largest trials - also judged to be high-quality and at low risk of bias - have yielded consistent results, and indicate that treatment does not alter rates of adverse pregnancy outcomes.

CONCLUSION

Non-surgical periodontal therapy, scaling and root planing, does not improve birth outcomes in pregnant women with periodontitis.

Ancestry informative markers and selected single nucleotide polymorphisms in immunoregulatory genes on preterm labor and preterm premature rupture of membranes: a case control study

Background

A genetic predisposition to Preterm Labor (PTL) and Preterm Premature Rupture of Membranes (PPROM) has been suggested; however the relevance of polymorphisms and ancestry to susceptibility to PTL and PPROM in different populations remains unclear. The aim of this study was to evaluate the contribution of maternal and fetal SNPs in the IL1B, IL6, IL6R, TNFA, TNFR, IL10, TLR2, TLR4, MMP9, TIMP1 and TIMP2 genes and the influence of ancestry background in the susceptibility to PTL or PPROM in Brazilian women.

Methods

Case–control study conducted at a tertiary hospital in São Paulo State, Brazil. We included women with PTL or PPROM and their babies (PTL: 136 women and 88 babies; PPROM: 65 women and 44 babies). Control group included 402 mother-babies pairs of term deliveries. Oral swabs were collected for identification of AIMs by fragment analysis and SNPs by Taqman® SNP Genotyping Assays and PCR. Linkage Disequilibrium and Hardy-Weinberg proportions were evaluated using Genepop 3.4. Haplotypes were inferred using the PHASE algorithm. Allele, genotype and haplotype frequencies were compared by Fisher’s exact test or χ² and Odds Ratio. Logistic regression was performed. Clinical and sociodemographic data were analyzed by Fisher’s exact test and Mann–Whitney.

Results

PTL was associated with European ancestry and smoking while African ancestry was protective. The fetal alleles IL10-592C (rs800872) and IL10-819C (rs1800871) were also associated with PTL and the maternal haplotype TNFA-308G-238A was protective. Maternal presence of IL10-1082G (rs1800896) and TLR2A (rs4696480) alleles increased the risk for PPROM while TNFA-238A (rs361525) was protective. Family history of PTL/PPROM was higher in cases, and time to delivery was influenced by IL1B-31T (rs1143627) and TLR4-299G (rs4986790).

Conclusion

There is an association between European ancestry and smoking and PTL in our Brazilian population sample. The presence of maternal or fetal alleles that modify the inflammatory response increase the susceptibility to PTL and PPROM. The family history of PTL/PPROM reinforces a role for genetic polymorphisms in susceptibility to these outcomes.

Elevated placenta growth factor levels in the early second-trimester amniotic fluid are associated with preterm delivery

OBJECTIVE

The purpose of this study was to determine how angiogenesis-related factors correlate with preterm delivery.

METHODS

A cohort of 382 pregnant women undergoing early second-trimester genetic amniocentesis was enrolled and followed-up until delivery, and the amniotic fluid was collected and stored as a nested case-control study. Cases with preterm delivery (n = 31) were compared with matched controls with term delivery (n = 62). The amniotic fluid concentrations of placenta growth factor (PlGF), angiogenins, angiopoietin-2, soluble fms-like tyrosine kinase and soluble endoglin were determined using enzyme-linked immunosorbent assays.

RESULTS

Women who delivered preterm had a higher amniotic PlGF concentration compared with the control group (median 12.6 pg/ml versus 6.1 pg/ml; p=0.027). Other angiogenesis-related factors did not show any differences between case and control groups. The odds ratio for preterm delivery based on amniotic fluid PlGF was 1.031 (95% confidence interval: 1.002-1.061; p=0.035). Additionally, when the cases were subdivided into early preterm, late preterm and term groups, PlGF values between the early preterm and term delivery groups were significantly different (median 16.6 pg/ml versus 6.1 pg/ml; Bonferroni-adjusted p=0.018).

CONCLUSION

Amniotic fluid PlGF levels in the early second trimester of pregnancy are associated with preterm delivery.

About one-half of early spontaneous preterm deliveries can be identified by a rapid matrix metalloproteinase-8 (MMP-8) bedside test at the time of mid-trimester genetic amniocentesis

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.

In vitro progesterone modulation on bacterial endotoxin-induced production of IL-1β, TNFα, IL-6, IL-8, IL-10, MIP-1α, and MMP-9 in pre-labor human term placenta

BACKGROUND

During human pregnancy, infection/inflammation represents an important factor that increases the risk of developing preterm labor. The purpose of this study was to determine if pre-treatment with progesterone has an immunomodulatory effect on human placenta production of endotoxin-induced inflammation and degradation of extracellular matrix markers.

METHODS

Placentas were obtained under sterile conditions from pregnancies delivered at term before the onset of labor by cesarean section. Explants from central cotyledons of 10 human placentas were pre-treated with different concentrations of progesterone (0.01, 01, 1.0 μM) and then stimulated with 1000 ng/mL of LPS of Escherichia coli. Cytokines TNFα, IL-1β, IL-6, IL-8, MIP-1α, IL-10 concentrations in the culture medium were then measured by specific ELISA. Secretion profile of MMP-9 was evaluated by ELISA and zymogram. Statistical differences were determined by one-way ANOVA followed by the appropriate ad hoc test; P < 0.05 was considered statistically significant.

RESULTS

In comparison to the explants incubated with vehicle, the LPS treatment led to a significant increase in the level of all cytokines. In comparison to the explants treated only with LPS, pre-treatment with 0.01-1.0 μM progesterone significantly blunted (73, 56, 56, 75, 25, 48 %) the secretion of TNF-α, IL-1β, IL-6, IL-8, MIP-1α, IL-10, respectively. The MMP-9 induced by LPS treatment was inhibited only with the highest concentration of progesterone. Mifepristone (RU486) blocked the immunosuppressive effect of progesterone.

CONCLUSIONS

The present results support the concept that progesterone could be part of the compensatory mechanism that limits the inflammation-induced cytotoxic effects associated with an infection process during gestation.

Acute chorioamnionitis and funisitis: definition, pathologic features, and clinical significance

Acute inflammatory lesions of the placenta consist of diffuse infiltration of neutrophils at different sites in the organ. These lesions include acute chorioamnionitis, funisitis, and chorionic vasculitis and represent a host response (maternal or fetal) to a chemotactic gradient in the amniotic cavity. While acute chorioamnionitis is evidence of a maternal host response, funisitis and chorionic vasculitis represent fetal inflammatory responses. Intraamniotic infection generally has been considered to be the cause of acute chorioamnionitis and funisitis; however, recent evidence indicates that "sterile" intraamniotic inflammation, which occurs in the absence of demonstrable microorganisms induced by "danger signals," is frequently associated with these lesions. In the context of intraamniotic infection, chemokines (such as interleukin-8 and granulocyte chemotactic protein) establish a gradient that favors the migration of neutrophils from the maternal or fetal circulation into the chorioamniotic membranes or umbilical cord, respectively. Danger signals that are released during the course of cellular stress or cell death can also induce the release of neutrophil chemokines. The prevalence of chorioamnionitis is a function of gestational age at birth, and present in 3-5% of term placentas and in 94% of placentas delivered at 21-24 weeks of gestation. The frequency is higher in patients with spontaneous labor, preterm labor, clinical chorioamnionitis (preterm or term), or ruptured membranes. Funisitis and chorionic vasculitis are the hallmarks of the fetal inflammatory response syndrome, a condition characterized by an elevation in the fetal plasma concentration of interleukin-6, and associated with the impending onset of preterm labor, a higher rate of neonatal morbidity (after adjustment for gestational age), and multiorgan fetal involvement. This syndrome is the counterpart of the systemic inflammatory response syndrome in adults: a risk factor for short- and long-term complications (ie, sterile inflammation in fetuses, neonatal sepsis, bronchopulmonary dysplasia, periventricular leukomalacia, and cerebral palsy). This article reviews the definition, pathogenesis, grading and staging, and clinical significance of the most common lesions in placental disease. Illustrations of the lesions and diagrams of the mechanisms of disease are provided.

Cytokine Levels in Late Pregnancy: Are Female Infants Better Protected Against Inflammation?

Inflammatory responses have been implicated in several forms of infant deaths (sudden expected deaths and stillbirths) and the initiation of pre-term births. In this study, we examined matched samples of term maternal blood, cord blood, and amniotic fluid obtained from 24 elective cesarean deliveries for both pro- and anti-inflammatory cytokines thought to be important in maintaining a balanced response leading to successful pregnancy outcome. These included interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), IL-10, and IL-1 receptor antagonist (IL-1ra). Amniotic fluid levels for each of the cytokines examined were significantly higher than those for cord blood or maternal plasma. While pro-inflammatory cytokines were higher in amniotic fluid associated with male fetuses compared with females, the major significant difference was higher levels of IL-1ra in amniotic fluid associated with female fetuses. Our study supports similar findings for cytokines during mid-trimester, which noted that amniotic fluid levels were higher than those in maternal blood. Our study suggests that maternal decidua secretes additional IL-ra in the presence of a female conceptus which improves the likelihood of a good outcome compared to pregnancies with male fetuses.

The Role of Infection and Inflammation in Stillbirths: Parallels with SIDS?

It has been suggested that stillbirths are part of the spectrum of infant deaths that includes sudden infant death syndrome (SIDS). This paper examines the hypothesis that risk factors associated with stillbirths might contribute to dysregulation of inflammatory responses to infections that could trigger the physiological responses leading to fetal loss. These include genetic factors (ethnic group, sex), environmental (infection, cigarette smoke, obesity), and developmental (testosterone levels) factors. Interactions between the genetic, environmental, and developmental risk factors are also considered, e.g., the excess of male stillborn infants in relation to the effects of testosterone levels during development on pro-inflammatory responses. In contrast to SIDS, inflammatory responses of both mother and fetus need to be considered. Approaches for examining the hypothesis are proposed.

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

OBJECTIVE

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

METHODS

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

RESULTS

(1) Patients with IAI had a significantly higher rate of acute HCA than those without IAI [76.9% (133/173)] versus 20.9% (50/239), p < 0.001]. The AF MMP-8 concentration was significantly higher in patients with acute HCA than in those without acute HCA (median [range]; 188.3 ng/ml [0.3-6142.6] versus 1.8 ng/ml [0.3-2845.5], p < 0.001); (2) Of 183 patients with acute HCA, the AF MMP-8 concentration was positively correlated with the severity of acute HCA (p < 0.001).

CONCLUSIONS

AF MMP-8 concentration was not only a predictor of the presence of acute HCA, but its concentration also correlated with the severity of acute HCA. The higher the intensity of IAI, the worse the degree of acute HCA in preterm gestation.

Amniotic coenzyme Q10: is it related to pregnancy outcomes?

Coenzyme Q10 (CoQ10 or ubiquinone) is an essential component of the mitochondrial electron transport chain and is also present in various cellular membranes and in plasma lipoproteins. Diabetes, cardiovascular, neurodegenerative, and preeclampsia diseases are all associated with an alteration of CoQ10 level or its redox status. During pregnancy, we note that the plasma content of CoQ10 is significantly higher than amniotic. In the fetal growth restriction group, amniotic total CoQ10 levels were significantly higher versus healthy, while the amniotic oxygen radical absorbing capacity level was significantly lower. A significant negative correlation was observed between amniotic total CoQ10 and birthweight. Our observation leads to the hypothesis that the amniotic midtrimester CoQ10 content may be a marker of subsequent obstetric complications.

Amniotic fluid infection, inflammation, and colonization in preterm labor with intact membranes

OBJECTIVE

The purpose of this study was to compare intraamniotic inflammation vs microbial invasion of the amniotic cavity (MIAC) as predictors of adverse outcome in preterm labor with intact membranes.

STUDY DESIGN

Interleukin-6 (IL-6) was measured in prospectively collected amniotic fluid from 305 women with preterm labor. MIAC was defined by amniotic fluid culture and/or detection of microbial 16S ribosomal DNA. Cases were categorized into 5 groups: infection (MIAC; IL-6, ≥11.3 ng/mL); severe inflammation (no MIAC; IL-6, ≥11.3 ng/mL); mild inflammation (no MIAC; IL-6, 2.6-11.2 ng/mL); colonization (MIAC; IL-6, <2.6 ng/mL); negative (no MIAC; IL-6, <2.6 ng/mL).

RESULTS

The infection (n = 27) and severe inflammation (n = 36) groups had similar latency (median, <1 day and 2 days, respectively) and similar rates of composite perinatal morbidity and mortality (81% and 72%, respectively). The colonization (n = 4) and negative (n = 195) groups had similar outcomes (median latency, 23.5 and 25 days; composite morbidity and mortality rates, 21% and 25%, respectively). The mild inflammation (n = 47) groups had outcomes that were intermediate to the severe inflammation and negative groups (median latency, 7 days; composite morbidity and mortality rates, 53%). In logistic regression adjusting for gestational age at enrollment, IL-6 ≥11.3 and 2.6-11.2 ng/mL, but not MIAC, were associated significantly with composite morbidity and mortality rates (odds ratio [OR], 4.9; 95% confidence interval [CI], 2.2-11.2, OR, 3.1; 95% CI, 1.5-6.4, and OR, 1.8; 95% CI, 0.6-5.5, respectively).

CONCLUSION

We confirmed previous reports that intraamniotic inflammation is associated with adverse perinatal outcomes whether or not intraamniotic microbes are detected. Colonization without inflammation appears relatively benign. Intraamniotic inflammation is not simply present or absent but also has degrees of severity that correlate with adverse outcomes. We propose the designation amniotic inflammatory response syndrome to denote the adverse outcomes that are associated with intraamniotic inflammation.

Soluble ST2, a modulator of the inflammatory response, in preterm and term labor

OBJECTIVE

Intra-amniotic infection/inflammation (IAI) is causally linked with spontaneous preterm labor and delivery. The ST2L receptor and its soluble form (sST2) are capable of binding to interleukin (IL)-33, a member of the IL-1 superfamily. Members of this cytokine family have been implicated in the onset of spontaneous preterm labor in the context of infection. Soluble ST2 has anti-inflammatory properties, and plasma concentrations are elevated in systemic inflammation, such as sepsis, acute pyelonephritis in pregnancy and the fetal inflammatory response syndrome. The aims of this study were to examine: (1) whether amniotic fluid concentrations of sST2 change with IAI, preterm, and term parturition; and (2) if mRNA expression of ST2 in the chorioamniotic membranes changes with acute histologic chorioamnionitis in women who deliver preterm.

METHOD

A cross-sectional study was conducted to determine amniotic fluid concentrations of sST2 in: (1) women with preterm labor (PTL) who delivered at term (n=49); (2) women with PTL who delivered preterm without IAI (n=21); (3) women with PTL who delivered preterm with IAI (n=31); (4) term pregnancies not in labor (n=13); and (5) term pregnancies in labor (n=43). The amniotic fluid concentration of sST2 was determined by ELISA. The mRNA expression of ST2 in the chorioamniotic membranes of women who delivered preterm with (n=24), and without acute histologic chorioamnionitis (n=19) was determined by qRT-PCR.

RESULTS

(1) Patients with PTL who delivered preterm with IAI had a lower median amniotic fluid concentration of sST2 compared to those with PTL who delivered preterm without IAI [median 410 ng/mL, inter-quartile range (IQR) 152-699 ng/mL versus median 825 ng/mL, IQR 493-1216 ng/mL; p=0.0003] and those with PTL who delivered at term [median 410 ng/mL, IQR 152-699 ng/mL versus median 673 ng/mL, IQR 468-1045 ng/mL; p=0.0003]; (2) no significant differences in the median amniotic fluid concentration of sST2 were observed between patients with PTL who delivered at term and those who delivered preterm without IAI (p=0.4), and between women at term in labor and those at term not in labor (p=0.9); (3) the mean mRNA expression of ST2 was 4-fold lower in women who delivered preterm with acute histologic chorioamnionitis than in those without this lesion (p=0.008).

CONCLUSIONS

The median sST2 amniotic fluid concentration and mRNA expression of ST2 by chorioamniotic membranes is lower in PTL associated with IAI and acute histologic chorioamnionitis than in PTL without these conditions. Changes in the median amniotic fluid sST2 concentration are not observed in preterm and term parturition without IAI. Thus, amniotic fluid sST2 in the presence of IAI behaves differently when compared to sST2 in the plasma of individuals affected by fetal inflammatory response syndrome, acute pyelonephritis in pregnancy, and adult sepsis. Decreased concentrations of sST2 in IAI are likely to promote a pro-inflammatory response, which is important for parturition in the context of infection.

IL-1β expression in the distal lung epithelium disrupts lung morphogenesis and epithelial cell differentiation in fetal mice

Perinatal inflammation and the inflammatory cytokine IL-1 can modify lung morphogenesis. To examine the effects of antenatal expression of IL-1β in the distal airway epithelium on fetal lung morphogenesis, we studied lung development and surfactant expression in fetal mice expressing human IL-1β under the control of the surfactant protein (SP)-C promoter. IL-1β-expressing pups suffered respiratory failure and died shortly after birth. IL-1β caused fetal lung inflammation and enhanced the expression of keratinocyte-derived chemokine (KC/CXCL1) and monocyte chemoattractant protein 3 (MCP-3/CCL7), the calgranulins S100A8 and S100A9, the acute-phase protein serum amyloid A3, the chitinase-like proteins Ym1 and Ym2, and pendrin. IL-1β decreased the percentage of the total distal lung area made up of air saccules and the number of air saccules in the lungs of fetal mice. IL-1β inhibited the expression of VEGF-A and its receptors VEGFR-1 and VEGFR-2. The percentage of the cellular area of the distal lung made up of capillaries was decreased in IL-1β-expressing fetal mice. IL-1β suppressed the production of SP-B and pro-SP-C and decreased the amount of phosphatidylcholine and the percentage of palmitic acid in the phosphatidylcholine fraction of lung phospholipids, indicating that IL-1β prevented the differentiation of type II epithelial cells. The production of Clara cell secretory protein in the nonciliated bronchiolar (Clara) cells was likewise suppressed by IL-1β. In conclusion, expression of IL-1β in the epithelium of the distal airways disrupted the development of the airspaces and capillaries in the fetal lung and caused fatal respiratory failure at birth.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Intra-amniotic infection/inflammation as a risk factor for subsequent ruptured membranes after clinically indicated amniocentesis in preterm labor

The aim of this study was to determine whether intra-amniotic infection/inflammation (IAI) was associated with subsequent ruptured membranes in women with preterm labor and intact membranes who had a clinically indicated amniocentesis. This retrospective cohort study included 237 consecutive women with preterm labor (20-34.6 weeks) who underwent amniocentesis. The clinical and laboratory parameters evaluated included demographic variables, gestational age, C-reactive protein (CRP) and amniotic fluid (AF) white blood cell, interleukin-6 (IL-6) and culture results. IAI was defined as a positive AF culture and/or an elevated AF IL-6 level (>2.6 ng/mL). The primary outcome was ruptured membranes in the absence of active labor occurring within 48 hours of amniocentesis. Preterm premature rupture of membranes subsequently developed in 10 (4.2%) women within 48 hr of amniocentesis. Multivariate analysis demonstrated that only IAI was independently associated with the ruptured membranes occurring within 48 hr of amniocentesis. In the predictive model based on variables assessed before amniocentesis, only CRP level was retained. IAI is an independent risk factor for subsequent ruptured membranes after clinically indicated amniocentesis in preterm labor. Prior to amniocentesis, measurement of serum CRP level can provide a risk assessment for the subsequent development of ruptured membranes after the procedure.

Risk of preterm delivery in non-diabetic women with polycystic ovarian syndrome

OBJECTIVE

To examine the risk and etiology of preterm delivery in women with polycystic ovary syndrome (PCOS).

STUDY DESIGN

Retrospective cohort study comparing preterm delivery rate among non-diabetic PCOS and non-PCOS women with singleton pregnancy. Multivariable logistic regression was used to identify predictors of preterm delivery among PCOS women.

RESULT

Among 908 PCOS women with singleton pregnancy, 12.9% delivered preterm compared with 7.4% among non-PCOS women (P<0.01). Causes of preterm delivery among PCOS women included preterm labor (41%), cervical insufficiency (11%), hypertensive complications (20%), preterm premature rupture of membranes (15%), fetal-placental concerns (9%) and intrauterine fetal demise (5%). Maternal age, race/ethnicity and nulliparity were significant predictors of preterm delivery in PCOS, whereas body mass index and fertility medications were not.

CONCLUSION

A higher proportion of PCOS women delivered preterm (12.9%) compared with non-PCOS women, with the majority of cases due to spontaneous preterm birth. Future studies should explore etiologies and strategies to improve pregnancy outcomes in PCOS.

Myometrial tumor necrosis factor-α receptors increase with gestation and labor and modulate gene expression through mitogen-activated kinase and nuclear factor-κB

Previously, we found that myometrial tumor necrosis factor-α (TNF-α) messenger RNA (mRNA) expression did not increase with preterm or term labor. To further investigate the role of TNF-α in human labor, we studied TNF-α receptor (TNFR1A and B) expression, regulation, and associated intracellular signaling pathways in human myometrial samples obtained both before and after the onset of labor and in primary cultures of uterine smooth muscle cells (USMCs). We found that the mRNA expression of both receptors increased with advancing gestation and labor and protein levels of TNFR1B were significantly higher in term laboring myometrial samples than in nonlabor controls. Tumor necrosis factor- treatment of USMCs activated all mitogen-activated protein kinase (MAPK) subtypes and nuclear factor κ-B (NF-κB). The TNF-α induced increases in the expression of TNFR1B and prostaglandin H synthase type 2 were reduced by inhibitors of NF-κB and MAPKs, respectively. The TNF-α induced increase in interleukin 8 (IL-8) appeared to be independent of MAPK and NF-κB pathway. These data suggest that the uterus may become more sensitive to the action of TNF-α with advancing gestation and labor and that TNF-α acts via MAPK and NF-κB to promote labor-associated gene expression.

Effects of amniotic and maternal CD-146, TGF-β1, IL-12, IL-18 and IFN-γ, on adverse pregnancy outcome

OBJECTIVE

Our aim was to determine the effects of maternal serum and amniotic fluid levels of cluster of differentiation 146 (CD-146), transforming growth factor (TGF)-β1, interleukin (IL)-12, IL-18, and interferon (IFN)-γ on intrauterine growth restriction and preterm labor.

METHODS

In this retrospective cohort study, we included pregnant women who underwent amniocentesis at Istanbul University Cerrahpasa Medical School. Women were followed up to labor. The study group comprised 23 women with adverse pregnancy outcomes (intrauterine growth restriction and preterm labor), and the control group comprised 105 women with normal pregnancy outcome.

RESULTS

The study group was further divided into two subgroups of preterm labor and intrauterine growth restriction. No significant differences were found for IL-12, IFN-γ, TGF-β1, or CD-146 levels in either plasma or amniotic fluid between the study and control groups. Serum IL-18 levels were similar, but the amniotic fluid level of IL-18 was significantly higher in the intrauterine growth restriction subgroup than that in the preterm labor subgroup and that in the control group (p < 0.01).

CONCLUSIONS

Increased IL-18 level in amniotic fluid may be a predictor for intrauterine growth restriction. IL-12, IFN-γ, TGF-β1, and CD-146 were not related to adverse pregnancy outcome.

Proteomic analysis of midtrimester amniotic fluid to identify novel biomarkers for preterm delivery

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.

Role of CXC chemokine receptor-2 in a murine model of bronchopulmonary dysplasia

The contribution of neutrophils and CXC chemokines to the pathogenesis of bronchopulmonary dysplasia is not well defined. The transgenic expression of IL-1β in the pulmonary epithelium causes lung inflammation and disrupts alveolar development in infant mice. To study the hypothesis that CXC chemokine receptor-2 (CXCR2) is a mediator of inflammatory lung injury, we compared lung development in IL-1β-expressing mice with wild-type (IL-1β/CXCR2(+/+)) or null (IL-1β/CXCR2(-/-)) CXCR2 loci. CXCR2 deficiency abolished the transmigration of neutrophils into the alveolar lumen in IL-1β-expressing mice, but did not alter the number of neutrophils in the parenchyma. The deletion of CXCR2 increased the alveolar chord length and reduced the survival of mice when IL-1β was expressed from the pseudoglandular to the alveolar stages. The capillary configuration was highly abnormal in both IL-1β/CXCR2(+/+) and IL-1β/CXCR2(-/-) lungs, but in very different ways. The cellular area of the parenchyma and the total capillary area of IL-1β/CXCR2(+/+) and IL-1β/CXCR2(-/-) mice were smaller than those of control/CXCR2(+/+) and control/CXCR2(-/-) mice, but the ratio of capillary area to cellular area was similar in all four genotypes. When IL-1β was expressed during the saccular stage, IL-1β/CXCR2(-/-) mice had smaller alveolar chord lengths and better survival than did IL-1β/CXCR2(+/+) mice. Independent of the timing of IL-1β expression, IL-1β increased alveolar septal thickness in mice with wild-type CXCR2 loci, but not in CXCR2 null mice. Depending on the developmental stage at the time of the inflammatory insult, inhibition of the CXCR2 pathway may exert opposite effects on alveolar septation in the neonatal lung.