Characterization of chorioamnionitis in 2nd-trimester C-section placentas and correlation with microorganism recovery from subamniotic tissues

The Role of Prevotella Species in Female Genital Tract Infections

Female genital tract infections (FGTIs) include vaginal infections (e.g., bacterial vaginosis [BV]), endometritis, pelvic inflammatory disease [PID], and chorioamnionitis [amniotic fluid infection]. They commonly occur in women of reproductive age and are strongly associated with multiple adverse health outcomes including increased risk of HIV/sexually transmitted infection acquisition and transmission, infertility, and adverse birth outcomes such as preterm birth. These FGTIs are characterized by a disruption of the cervicovaginal microbiota which largely affects host immunity through the loss of protective, lactic acid-producing Lactobacillus spp. and the overgrowth of facultative and strict anaerobic bacteria. Prevotella species (spp.), anaerobic Gram-negative rods, are implicated in the pathogenesis of multiple bacterial FGTIs. Specifically, P. bivia, P. amnii, and P. timonensis have unique virulence factors in this setting, including resistance to antibiotics commonly used in treatment. Additionally, evidence suggests that the presence of Prevotella spp. in untreated BV cases can lead to infections of the upper female genital tract by ascension into the uterus. This narrative review aims to explore the most common Prevotella spp. in FGTIs, highlight their important role in the pathogenesis of FGTIs, and propose future research in this area.

Environmental influences on child health outcomes: cohorts of individuals born very preterm

The National Institutes of Health's Environmental influences on Child Health Outcomes (ECHO) Program was designed to address solution-oriented research questions about the links between children's early life environment and their risks of pre-, peri-, and post-natal complications, asthma, obesity, neurodevelopmental disorders, and positive health. Children born very preterm are at increased risk for many of the outcomes on which ECHO focuses, but the contributions of environmental factors to this risk are not well characterized. Three ECHO cohorts consist almost exclusively of individuals born very preterm. Data provided to ECHO from cohorts can be used to address hypotheses about (1) differential risks of chronic health and developmental conditions between individuals born very preterm and those born at term; (2) health disparities across social determinants of health; and (3) mechanisms linking early-life exposures and later-life outcomes among individuals born very preterm. IMPACT: The National Institutes of Health's Environmental Influences on Child Health Outcomes Program is conducting solution-oriented research on the links between children's environment and health. Three ECHO cohorts comprise study participants born very preterm; these cohorts have enrolled, to date, 1751 individuals born in 14 states in the U.S. in between April 2002 and March 2020. Extensive data are available on early-life environmental exposures and child outcomes related to neurodevelopment, asthma, obesity, and positive health. Data from ECHO preterm cohorts can be used to address questions about the combined effects of preterm birth and environmental exposures on child health outcomes.

Differential placental CpG methylation is associated with chronic lung disease of prematurity

BACKGROUND

Chronic lung disease (CLD) is the most common pulmonary morbidity in extremely preterm infants. It is unclear to what extent prenatal exposures influence the risk of CLD. Epigenetic variation in placenta DNA methylation may be associated with differential risk of CLD, and these associations may be dependent upon sex.

METHODS

Data were obtained from a multi-center cohort of infants born extremely preterm (<28 weeks' gestation) and an epigenome-wide approach was used to identify associations between placental DNA methylation and CLD (n = 423). Associations were evaluated using robust linear regression adjusting for covariates, with a false discovery rate of 0.05. Analyses stratified by sex were used to assess differences in methylation-CLD associations.

RESULTS

CLD was associated with differential methylation at 49 CpG sites representing 46 genes in the placenta. CLD was associated with differential methylation of probes within genes related to pathways involved in fetal lung development, such as p53 signaling and myo-inositol biosynthesis. Associations between CpG methylation and CLD differed by sex.

CONCLUSIONS

Differential placental methylation within genes with key roles in fetal lung development may reflect complex cell signaling between the placenta and fetus which mediate CLD risk. These pathways appear to be distinct based on fetal sex.

IMPACT

In extremely preterm infants, differential methylation of CpG sites within placental genes involved in pathways related to cell signaling, oxidative stress, and trophoblast invasion is associated with chronic lung disease of prematurity. DNA methylation patterns associated with chronic lung disease were distinctly based on fetal sex, suggesting a potential mechanism underlying dimorphic phenotypes. Mechanisms related to fetal hypoxia and placental myo-inositol signaling may play a role in fetal lung programming and the developmental origins of chronic lung disease. Continued research of the relationship between the placental epigenome and chronic lung disease could inform efforts to ameliorate or prevent this condition.

Fetal heart rate variability is a biomarker of rapid but not progressive exacerbation of inflammation in preterm fetal sheep

Perinatal infection/inflammation can trigger preterm birth and contribute to neurodevelopmental disability. There are currently no sensitive, specific methods to identify perinatal infection. We investigated the utility of time, frequency and non-linear measures of fetal heart rate (FHR) variability (FHRV) to identify either progressive or more rapid inflammation. Chronically instrumented preterm fetal sheep were randomly assigned to one of three different 5d continuous i.v. infusions: 1) control (saline infusions; n = 10), 2) progressive lipopolysaccharide (LPS; 200 ng/kg over 24 h, doubled every 24 h for 5d, n = 8), or 3) acute-on-chronic LPS (100 ng/kg over 24 h then 250 ng/kg/24 h for 4d plus 1 μg boluses at 48, 72, and 96 h, n = 9). Both LPS protocols triggered transient increases in multiple measures of FHRV at the onset of infusions. No FHRV or physiological changes occurred from 12 h after starting progressive LPS infusions. LPS boluses during the acute-on-chronic protocol triggered transient hypotension, tachycardia and an initial increase in multiple time and frequency domain measures of FHRV, with an asymmetric FHR pattern of predominant decelerations. Following resolution of hypotension after the second and third LPS boluses, all frequencies of FHRV became suppressed. These data suggest that FHRV may be a useful biomarker of rapid but not progressive preterm infection/inflammation.

Human fetal membrane IL-1β production in response to bacterial components is mediated by uric-acid induced NLRP3 inflammasome activation

Inflammatory interleukin-1β (IL-1β) is an important mediator of preterm birth. IL-1β secretion is mediated by the inflammasome that processes pro-IL-1β into its active form. However the mechanisms involved at the level of the fetal membrane (FM) are not fully understood. This study sought to determine the FM compartment involved in IL-1β production in response to bacterial components and to evaluate the mechanism of inflammasome activation. Since IL-18 is also mediated by the inflammasome and IL-8 is a chemoattractant that contributes to neutrophil recruitment in chorioamnionitis, we also evaluated the production of these factors. A human explant system was used to evaluate the response of the chorion, amnion, and intact FMs to the bacterial components lipopolysaccharide (LPS), peptidoglycan (PGN), or muramyl dipeptide (MDP). The chorion was the major source of IL-1β and IL-8 production in response to LPS, PGN, and MDP. LPS, PGN, and MDP induced FM IL-1β and IL-18 secretion in a non-pyroptotic manner through activation of the NLRP3 inflammasome with contributions from ATP release through Pannexin-1, and ROS signaling. Since LPS, PGN, and MDP are not known to activate NLRP3 directly, the role of uric acid as a potential mediator was assessed. FMs produced elevated uric acid in response to LPS, PGN and MDP. FM IL-1β secretion was inhibited by allopurinol, which blocks uric acid production, for LPS and PGN, and to a lesser degree, MDP. These findings shed light on the mechanisms by which fetal membrane inflammation and subsequent preterm birth may arise.

Endometrial Microbiome and Women’s Reproductive Health – Review of the Problem Endometrial Microbiome and Reproductive Health

Currently, unlike in the past, the endometrial cavity is not considered to be sterile. The endometrium is supposed to be dominated by Lactobacilli, but also their deficiency can be found in the reproductive tract of asymptomatic healthy women. Sometimes the endometrial microbiome is dominated by various pathological microorganisms, and this can lead to various conditions as chronic endometritis, chorioamnionitis and preterm birth. Their presence causes uterine inflammation and infection, release of pro-inflammatory molecules, uterine contractions, disruption of cervical barrier, premature rupture of membranes. Uterine dysbiosis is associated with recurrent implantation failure and recurrent miscarriages. As the microbiome is important for maintaining immunological homeostasis at the level of gastrointestinal tract Lactobacilli may play a similar function at the level of uterus. The lactobacillus-dominated uterine microbiome is of great importance for maintaining a hostile uterine microenvironment, embryo implantation, early pregnancy development and normal pregnancy outcome.

Placental histopathology in preterm birth with confirmed maternal infection: A systematic literature review

Four in five neonatal deaths of preterm births occur in low and middle income countries and placental histopathology examination can help clarify the pathogenesis. Infection is known to play a significant role in preterm birth. The aim of this systematic review is to explore the association between placental histopathological abnormality and preterm birth in the presence of confirmed infection. PubMed/Medline, Scopus, Web of Science and Embase were searched using the keywords related to preterm birth, placental histopathology and infection. Titles and abstracts were screened and the full texts of eligible articles were reviewed to extract and summarise data. Of 1529 articles, only 23 studies (13 bacterial, 6 viral and 4 parasitic) were included, and they used 7 different gestational age windows, and 20 different histopathological classification systems, precluding data pooling. Despite this, histopathological chorioamnionitis, and funisitis (when examined) were commonly observed in preterm birth complicated by confirmed bacterial or viral, but not parasitic, infection. The presence of malaria parasites but not pigment in placenta was reported to increase the risk of PTB, but this finding was inconclusive. One in three studies were conducted in low and middle income countries. An array of: definitions of preterm birth subgroups, histological classification systems, histopathologic abnormalities and diagnostic methods to identify infections were reported in this systematic review. Commitment to using standardised terminology and classification of histopathological abnormalities associated with infections is needed to identify causality and potential treatment of preterm birth. Studies on preterm birth needs to occur in high burden countries and control for clinical characteristics (maternal, fetal, labor, and placental) that may have an impact on placental histopathological abnormalities.

Pre-pregnancy BMI-associated miRNA and mRNA expression signatures in the placenta highlight a sexually-dimorphic response to maternal underweight status

Pre-pregnancy body mass index (BMI) is associated with adverse pregnancy and neonatal health outcomes, with differences in risk observed between sexes. Given that the placenta is a sexually dimorphic organ and critical regulator of development, examining differences in placental mRNA and miRNA expression in relation to pre-pregnancy BMI may provide insight into responses to maternal BMI in utero. Here, genome-wide mRNA and miRNA expression levels were assessed in the placentas of infants born extremely preterm. Differences in expression were evaluated according to pre-pregnancy BMI status (1) overall and (2) in male and female placentas separately. Overall, 719 mRNAs were differentially expressed in relation to underweight status. Unexpectedly, no genes were differentially expressed in relation to overweight or obese status. In male placentas, 572 mRNAs were associated with underweight status, with 503 (70%) overlapping genes identified overall. Notably, 43/572 (8%) of the mRNAs associated with underweight status in male placentas were also gene targets of two miRNAs (miR-4057 and miR-128-1-5p) associated with underweight status in male placentas. Pathways regulating placental nutrient metabolism and angiogenesis were among those enriched in mRNAs associated with underweight status in males. This study is among the first to highlight a sexually dimorphic response to low pre-pregnancy BMI in the placenta.

Acute chorioamnionitis and intra-amniotic inflammation are more severe according to outside-in neutrophil migration within the same chorio-decidua

OBJECTIVE

No information exists about whether acute histologic chorioamnionitis (acute-HCA) is more advanced and severe, and intra-amniotic inflammation is more frequent and intense according to outside in neutrophil migration within the same chorio-decidua. The objective of current study is to examine this issue.

MATERIALS AND METHODS

We included 106 singleton preterm-births (gestational age at delivery: 20-34 weeks) due to either preterm-labor or preterm-PROM in the context of acute chorio-deciduitis. Study-population was divided into 3 groups according to outside-in neutrophil migration within chorio-decidua as follows: 1) group-1: 'inflammation restricted to the decidua' (n = 22); 2) group-2: 'inflammation restricted to the MT of chorion and the decidua' (n = 31); 3) group-3: 'inflammation in the CT of chorion' (n = 53). We examined the frequency of inflammation in each placental compartment beyond chorio-decidua (i.e., amnion, umbilical cord, and chorionic-plate), and total grade (1-8) of acute-HCA. Moreover, the frequency of intra-amniotic infection (defined as positive amniotic-fluid culture for aerobic and anaerobic bacteria and genital mycoplasmas) and intra-amniotic inflammation (defined as amniotic fluid WBC ≥ 19 cells/mm³), and an intra-amniotic inflammatory response gauged by amnioticfluid WBC count (cells/mm³) were examined in 50 amniotic fluid samples within 7 days of birth.

RESULTS

Amnionitis, funisitis and chorionic plate inflammation were more frequent (each for P < 0.01) and median total grade of acute-HCA was increased (P < 0.001) according to outside-in neutrophil migration within chorio-decidua (group-1vs.group-2vs.group-3). Moreover, intra-amniotic infection and inflammation were more frequent (each-for P < 0.05) and median amniotic-fluid WBC count was increased (P < 0.01) according-to outside-in neutrophil-migration within chorio-decidua (group-1 vs. group-2 vs. group-3).

CONCLUSION

Acute-HCA is more advanced and severe, and intra-amniotic inflammation is more frequent and intense according to outside in neutrophil migration within the same chorio-decidua. This finding suggests that what is now acute chorio-deciduitis should be subdivided.

Placental programming, perinatal inflammation, and neurodevelopment impairment among those born extremely preterm

Individuals born extremely preterm are at significant risk for impaired neurodevelopment. After discharge from the neonatal intensive care, associations between the child's well-being and factors in the home and social environment become increasingly apparent. Mothers' prenatal health and socioeconomic status are associated with neurodevelopmental outcomes, and emotional and behavioral problems. Research on early life risk factors and on mechanisms underlying inter-individual differences in neurodevelopment later in life can inform the design of personalized approaches to prevention. Here, we review early life predictors of inter-individual differences in later life neurodevelopment among those born extremely preterm. Among biological mechanisms that mediate relationships between early life predictors and later neurodevelopmental outcomes, we highlight evidence for disrupted placental processes and regulated at least in part via epigenetic mechanisms, as well as perinatal inflammation. In relation to these mechanisms, we focus on four prenatal antecedents of impaired neurodevelopment, namely, (1) fetal growth restriction, (2) maternal obesity, (3) placental microorganisms, and (4) socioeconomic adversity. In the future, this knowledge may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm. IMPACT: This review highlights early life risk factors and mechanisms underlying inter-individual differences in neurodevelopment later in life. The review emphasizes research on early life risk factors (fetal growth restriction, maternal obesity, placental microorganisms, and socioeconomic adversity) and on mechanisms (disrupted placental processes and perinatal inflammation) underlying inter-individual differences in neurodevelopment later in life. The findings highlighted here may inform efforts to detect and prevent adverse outcomes in infants born extremely preterm.

Histologic chorioamnionitis and risk of neurodevelopmental impairment at age 10 years among extremely preterm infants born before 28 weeks of gestation

BACKGROUND

Extremely preterm infants whose placenta had histologic evidence of chorioamnionitis have early brain dysfunction, but little is known about neurologic development at 10 years of age.

OBJECTIVE

We investigated the association between histologic chorioamnionitis and neurodevelopmental impairment at 10 years among children born <28 weeks' gestation (extremely preterm).

STUDY DESIGN

The multicenter Extremely Low Gestational Age Newborns study enrolled extremely preterm newborns from 2002 to 2004 at 14 hospitals in the United States. Chorioamnionitis was defined by histologic stage (early, moderate, and advanced) and grade (mild/moderate and severe) of chorionic plate and umbilical cord inflammation. The children were examined for cerebral palsy at 2 years and for autism spectrum disorder, cognitive impairment (intelligence quotient >2 standard deviations below the mean), and epilepsy at the age of 10 years by blinded evaluators using validated measures. Multivariable logistic regression with generalized estimating equations was used.

RESULTS

Among 805 placentas, 43% (347/805) had histologic chorioamnionitis by moderate or advanced maternal stage, 36% (286/805) by severe maternal grade, 18% (132/737) by moderate or advanced fetal stage, and 1% (10/737) by severe fetal grade. The frequencies of impairments were 11% (88/767) for cerebral palsy, 7% (56/773) for autism spectrum disorder, 15% (120/788) for cognitive impairment, and 7% (52/763) for epilepsy. After adjustment for maternal age, body mass index, race, insurance status, maternal education, tobacco use, infant sex, and multiple gestations, the adjusted odds ratio for the association between histologic chorioamnionitis and cerebral palsy years was increased with advanced maternal stage (adjusted odds ratio, 2.5; 95% confidence interval, 1.6-3.9), severe maternal grade (adjusted odds ratio, 2.0; 95% confidence interval, 1.2-3.4), moderate fetal stage (adjusted odds ratio, 2.20; 95% confidence interval, 2.1-2.2), and mild or moderate fetal grade (adjusted odds ratio, 1.5; 95% confidence interval, 1.0-2.2). Similarly, the adjusted odds ratio for the association between histologic chorioamnionitis and epilepsy was increased with advanced maternal stage (adjusted odds ratio, 1.5; 95% confidence interval, 1.3-1.6) and severe fetal grade (adjusted odds ratio, 5.9; 95% confidence interval, 1.9-17.8). In addition, the adjusted odds ratio for the association between histologic chorioamnionitis and autism spectrum disorder was increased with mild or moderate fetal grade (adjusted odds ratio, 1.7; 95% confidence interval, 1.0-2.9). Histologic chorioamnionitis was not associated with cognitive impairment. These findings held after adjustment for gestational age at delivery. In contrast to histologic chorioamnionitis, a clinical diagnosis of chorioamnionitis was not associated with neurodevelopmental impairment.

CONCLUSION

Histologic chorioamnionitis may be associated with some forms of neurodevelopmental impairment at 10 years of life among infants born <28 weeks' gestation.

An Updated Conceptual Model on the Pathogenesis of Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common cause of vaginal discharge. It is associated with an increased risk of preterm delivery, pelvic inflammatory disease, and an increased risk of acquisition of sexually transmitted infections including human immunodeficiency virus (HIV). The epidemiology of BV supports sexual transmission. However, its etiology remains unknown. At the center of the debate is whether BV is caused by a primary pathogen or a polymicrobial consortium of microorganisms that are sexually transmitted. We previously published a conceptual model hypothesizing that BV is initiated by sexual transmission of Gardnerella vaginalis. Critics of this model have iterated that G. vaginalis is found in virginal women and in sexually active women with a normal vaginal microbiota. In addition, colonization does not always lead to BV. However, recent advances in BV pathogenesis research have determined the existence of 13 different species within the genus Gardnerella. It may be that healthy women are colonized by nonpathogenic Gardnerella species, whereas virulent strains are involved in BV development. Based on our results from a recent prospective study, in addition to an extensive literature review, we present an updated conceptual model for the pathogenesis of BV that centers on the roles of virulent strains of G. vaginalis, as well as Prevotella bivia and Atopobium vaginae.

Fetal membrane bacterial load is increased in histologically confirmed inflammatory chorioamnionitis: A retrospective cohort study

INTRODUCTION

It is widely debated whether fetal membranes possess a genuine microbiome, and if bacterial presence and load is linked to inflammation. Chorioamnionitis is an inflammation of the fetal membranes. This research focussed on inflammatory diagnosed histological chorioamnionitis (HCA) and aimed to determine whether the bacterial load in fetal membranes correlates to inflammatory response, including histological staging and inflammatory markers in HCA.

METHODS

Fetal membrane samples were collected from patients with preterm spontaneous labour and histologically phenotyped chorioamnionitis (HCA; n = 12), or preterm (n = 6) and term labour without HCA (n = 6). The bacterial profile of fetal membranes was analysed by sequencing the V4 region of the 16S rRNA gene. Bacterial load was determined using qPCR copy number/mg of tissue. The association between bacterial load and bacterial profile composition was assessed using correlation analysis.

RESULTS

Bacterial load was significantly greater within HCA amnion (p = 0.002) and chorion (p = 0.042), compared to preterm birth without HCA. Increased bacterial load was positively correlated with increased histological staging (p = 0.001) and the expression of five inflammatory markers; IL8, TLR1, TLR2, LY96 and IRAK2 (p=<0.050). Bacterial profiles were significantly different between membranes with and without HCA in amnion (p = 0.012) and chorion (p = 0.001), but no differences between specific genera were detected.

DISCUSSION

Inflammatory HCA is associated with infection and increased bacterial load in a dose response relationship. Bacterial load is positively correlated with HCA severity and the TLR signalling pathway. Further research should investigate the bacterial load threshold required to generate an inflammatory response in HCA.

Modulation of Placental Gene Expression in Small-for-Gestational-Age Infants

Small-for-gestational-age (SGA) infants are fetuses that have not reached their genetically programmed growth potential. Low birth weight predisposes these infants to an increased risk of developing cardiovascular, metabolic and neurodevelopmental conditions in later life. However, our understanding of how this pathology occurs is currently incomplete. Previous research has focused on understanding the transcriptome, epigenome and bacterial signatures separately. However, we hypothesise that interactions between moderators of gene expression are critical to understanding fetal growth restriction. Through a review of the current literature, we identify that there is evidence of modulated expression/methylation of the placental genome and the presence of bacterial DNA in the placental tissue of SGA infants. We also identify that despite limited evidence of the interactions between the above results, there are promising suggestions of a relationship between bacterial signatures and placental function. This review aims to summarise the current literature concerning fetal growth from multiple avenues and propose a novel relationship between the placental transcriptome, methylome and bacterial signature that, if characterised, may be able to improve our current understanding of the placental response to stress and the aetiology of growth restriction.

Early Postnatal IGF-1 and IGFBP-1 Blood Levels in Extremely Preterm Infants: Relationships with Indicators of Placental Insufficiency and with Systemic Inflammation

OBJECTIVE

To evaluate to what extent indicators of placenta insufficiency are associated with low concentrations of insulin-like growth factor 1 (IGF-1) and IGF-1-binding protein-1 (IGFBP-1) in neonatal blood, and to what extent the concentrations of these growth factors are associated with concentrations of proteins with inflammatory, neurotrophic, or angiogenic properties.

STUDY DESIGN

Using multiplex immunoassays, we measured the concentrations of IGF-1 and IGFBP-1, as well as 25 other proteins in blood spots collected weekly from ≥ 880 infants born before the 28th week of gestation, and sought correlates of concentrations in the top and bottom quartiles for gestational age and day the specimen was collected.

RESULTS

Medically indicated delivery and severe fetal growth restriction (sFGR) were associated with low concentrations of IGF-1 on the first postnatal day and with high concentrations of IGFBP-1 on almost all days. Elevated concentrations of IGF-1 and IGFBP-1 were accompanied by elevated concentrations of many other proteins with inflammatory, neurotrophic, or angiogenic properties.

CONCLUSION

Disorders associated with impaired placenta implantation and sFGR appear to account for a relative paucity of IGF-1 on the first postnatal day. Elevated concentrations of IGF-1 and especially IGFBP-1 were associated with same-day elevated concentrations of inflammatory, neurotrophic, and angiogenic proteins.

Gardnerella vaginalis and Prevotella bivia Trigger Distinct and Overlapping Phenotypes in a Mouse Model of Bacterial Vaginosis

BACKGROUND

Bacterial vaginosis (BV) is a common imbalance of the vaginal microbiota characterized by overgrowth of diverse Actinobacteria, Firmicutes, and Gram-negative anaerobes. Women with BV are at increased risk of secondary reproductive tract infections and adverse pregnancy outcomes. However, which specific bacteria cause clinical features of BV is unclear.

METHODS

We previously demonstrated that Gardnerella vaginalis could elicit many BV features in mice. In this study, we established a BV model in which we coinfected mice with G. vaginalis and another species commonly found in women with BV: Prevotella bivia.

RESULTS

This coinfection model recapitulates several aspects of human BV, including vaginal sialidase activity (a diagnostic BV feature independently associated with adverse outcomes), epithelial exfoliation, and ascending infection. It is notable that G. vaginalis facilitated uterine infection by P. bivia.

CONCLUSIONS

Taken together, our model provides a framework for advancing our understanding of the role of individual or combinations of BV-associated bacteria in BV pathogenesis.

Epigenome-wide DNA methylation in placentas from preterm infants: association with maternal socioeconomic status

This study evaluated the hypothesis that prenatal maternal socioeconomic status (SES) adversity is associated with DNA methylation in the placenta. SES adversity was defined by the presence of, as well as a summative count of, four factors: less than college education, single marital status, food and nutritional service assistance, and public health insurance. Epigenome-wide DNA methylation was assessed using the Illumina EPIC array in 426 placentas from a sample of infants born < 28 weeks of gestation from the Extremely Low Gestational Age Newborn cohort. Associations between SES adversity and DNA methylation were assessed with robust linear regressions adjusted for covariates and controlled the false discovery rate at < 10%. We also examined whether such associations were sex specific. Indicators of SES adversity were associated with differential methylation at 33 CpG sites. Of the 33 identified CpG sites, 19 (57.6%) displayed increased methylation, and 14 (42.4%) displayed decreased methylation in association with at least one of the SES adversity factors. Sex differences were observed in DNA methylation associated with summative SES score; in which placentas derived from female pregnancies showed more robust differential CpG methylation than placentas from male pregnancies. Maternal SES adversity was associated with differential methylation of genes with key role in gene transcription and placental function, potentially altering immunity and stress response. Further investigation is needed to evaluate the role of epigenetic differences in mediating the association between maternal socioeconomic status during pregnancy and later life health outcomes in children.

Does the human placenta delivered at term have a microbiota? Results of cultivation, quantitative real-time PCR, 16S rRNA gene sequencing, and metagenomics

BACKGROUND

The human placenta has been traditionally viewed as sterile, and microbial invasion of this organ has been associated with adverse pregnancy outcomes. Yet, recent studies that utilized sequencing techniques reported that the human placenta at term contains a unique microbiota. These conclusions are largely based on the results derived from the sequencing of placental samples. However, such an approach carries the risk of capturing background-contaminating DNA (from DNA extraction kits, polymerase chain reaction reagents, and laboratory environments) when low microbial biomass samples are studied.

OBJECTIVE

To determine whether the human placenta delivered at term in patients without labor who undergo cesarean delivery harbors a resident microbiota ("the assemblage of microorganisms present in a defined niche or environment").

STUDY DESIGN

This cross-sectional study included placentas from 29 women who had a cesarean delivery without labor at term. The study also included technical controls to account for potential background-contaminating DNA, inclusive in DNA extraction kits, polymerase chain reaction reagents, and laboratory environments. Bacterial profiles of placental tissues and background technical controls were characterized and compared with the use of bacterial culture, quantitative real-time polymerase chain reaction, 16S ribosomal RNA gene sequencing, and metagenomic surveys.

RESULTS

(1) Twenty-eight of 29 placental tissues had a negative culture for microorganisms. The microorganisms retrieved by culture from the remaining sample were likely contaminants because corresponding 16S ribosomal RNA genes were not detected in the same sample. (2) Quantitative real-time polymerase chain reaction did not indicate greater abundances of bacterial 16S ribosomal RNA genes in placental tissues than in technical controls. Therefore, there was no evidence of the presence of microorganisms above background contamination from reagents in the placentas. (3) 16S ribosomal RNA gene sequencing did not reveal consistent differences in the composition or structure of bacterial profiles between placental samples and background technical controls. (4) Most of the bacterial sequences obtained from metagenomic surveys of placental tissues were from cyanobacteria, aquatic bacteria, or plant pathogens, which are microbes unlikely to populate the human placenta. Coprobacillus, which constituted 30.5% of the bacterial sequences obtained through metagenomic sequencing of placental samples, was not identified in any of the 16S ribosomal RNA gene surveys of these samples. These observations cast doubt as to whether this organism is really present in the placenta of patients at term not in labor.

CONCLUSION

With the use of multiple modes of microbiologic inquiry, a resident microbiota could not be identified in human placentas delivered at term from women without labor. A consistently significant difference in the abundance and/or presence of a microbiota between placental tissue and background technical controls could not be found. All cultures of placental tissue, except 1, did not yield bacteria. Incorporating technical controls for potential sources of background-contaminating DNA for studies of low microbial biomass samples, such as the placenta, is necessary to derive reliable conclusions.

Understanding Fetal Heart Rate Patterns That May Predict Antenatal and Intrapartum Neural Injury

Electronic fetal heart rate (FHR) monitoring is widely used to assess fetal well-being throughout pregnancy and labor. Both antenatal and intrapartum FHR monitoring are associated with a high negative predictive value and a very poor positive predictive value. This in part reflects the physiological resilience of the healthy fetus and the remarkable effectiveness of fetal adaptations to even severe challenges. In this way, the majority of "abnormal" FHR patterns in fact reflect a fetus' appropriate adaptive responses to adverse in utero conditions. Understanding the physiology of these adaptations, how they are reflected in the FHR trace and in what conditions they can fail is therefore critical to appreciating both the potential uses and limitations of electronic FHR monitoring.

The Absence of TLR4 Prevents Fetal Brain Injury in the Setting of Intrauterine Inflammation

BACKGROUND

Exposure to intrauterine inflammation during pregnancy is linked to brain injury and neurobehavioral disorders in affected children. Innate immunity, specifically Toll-like receptor (TLR) signaling pathways are present throughout the reproductive tract as well as in the placenta, fetal membranes, and fetus. The TLR pathways are mechanistically involved in host responses to foreign pathogens and may lead to brain injury associated with prenatal inflammation.

OBJECTIVE

We aimed to determine whether the activation of the TLR4 signaling pathway, in the mother and fetus, is critical to fetal brain injury in the setting of intrauterine inflammation.

METHODS

A mini-laparotomy was performed on time pregnant C57B6 mice and 2 knockout mouse strains lacking the function of the Tlr4 and Myd88 genes on embryonic day 15. Intrauterine injections of Escherichia coli lipopolysaccharide or saline were administered as described previously. Dams were killed 6 hours postsurgery, and placental, amniotic fluid, and fetal brain tissue were collected. To assess brain injury, quantitative polymerase chain reaction (qPCR) analysis was performed on multiple components of the NOTCH signaling pathway, including Hes genes. Interleukin (IL) IL6, IL1β, and CCL5 expression was assessed using qPCR and enzyme-linked immunosorbent assay.

RESULTS

Using an established mouse model of intrauterine inflammation, we demonstrate that the abrogation of TLR4 signaling eliminates the cytokine response in mother and fetus and prevents brain injury associated with increased expression of transcriptional effectors of the NOTCH signaling pathway, Hes1 and Hes5.

CONCLUSIONS

These data show that the activation of the TLR4 signaling pathway is necessary for the development of fetal brain injury in response to intrauterine inflammation.

Antecedents of Obesity Among Children Born Extremely Preterm

BACKGROUND

Childhood obesity is a pervasive public health problem with risk factors such as maternal prepregnancy BMI and rapid infant weight gain. Although catch-up weight gain promotes more favorable neurodevelopment among infants born preterm, it is not clear whether faster weight gain early in life, or other correlates of preterm birth, are associated with later obesity in this population.

METHODS

We used prospective data from the multicenter, observational Extremely Low Gestational Age Newborn Study. Among 1506 eligible individuals in the initial cohort, 1198 were eligible for follow-up at 10 years of age. We examined BMI in 871 children (58% of the cohort; 74% of survivors) and analyzed relationships between antecedents and overweight or obesity at 10 years of age. A time-oriented approach to multinomial multivariable regression enabled us to calculate odds of overweight and obesity associated with pre- and postnatal antecedents.

RESULTS

Prepregnancy maternal BMI ≥25 and top quartile infant weight gain in the first year were associated with increased risk of both overweight and obesity at 10 years of age. Single marital status was a risk factor for later child obesity and exposure to tobacco smoke was a risk factor for later child overweight.

CONCLUSIONS

The risk profiles for overweight and obesity at 10 years of age among children born extremely preterm appear to be similar to the risk profiles of overweight and obesity among children born at term.

Are Extremely Low Gestational Age Newborns Born to Obese Women at Increased Risk of Cerebral Palsy at 2 Years?

The authors hypothesized that the risk of cerebral palsy at 2 years in children born extremely preterm to overweight and obese women is increased relative to the risk among children born to neither overweight nor obese women. In a multicenter prospective cohort study, the authors created multinomial logistic regression models of the risk of diparetic, quadriparetic, and hemiparetic cerebral palsy that included the prepregnancy body mass index of mothers of 1014 children born extremely preterm, cerebral palsy diagnoses of children at 2 years, as well as information about potential confounders. Overweight and obese women were not at increased risk of giving birth to a child who had cerebral palsy. The risk ratios associated with overweight varied between 1.1 for quadriparesis (95% CI = 0.5, 2.1) to 2.0 for hemiparesis (95% CI = 0.4, 9.8). The risk ratios associated with obesity varied between 0.7 for diparesis (95% CI = 0.2, 2.5) to 2.5 for hemiparesis (95% CI = 0.4, 13).

Both antenatal and postnatal inflammation contribute information about the risk of brain damage in extremely preterm newborns

BackgroundPreterm newborns exposed to intrauterine inflammation are at an increased risk of neurodevelopmental disorders. We hypothesized that adverse outcomes are more strongly associated with a combination of antenatal and postnatal inflammation than with either of them alone.MethodsWe defined antenatal inflammation as histologic inflammation in the placenta. We measured the concentrations of seven inflammation-related proteins in blood obtained on postnatal days 1, 7, and 14 from 763 infants born before 28 weeks of gestation. We defined postnatal inflammation as a protein concentration in the highest quartile on at least 2 days. We used logistic regression models to evaluate the contribution of antenatal and postnatal inflammation to the risk of neurodevelopmental disorders.ResultsThe risk of white matter damage was increased when placental inflammation was followed by sustained elevation of C-reactive protein or ICAM-1. We found the same for spastic cerebral palsy when placental inflammation was followed by elevation of TNF-α or IL-8. The presence of both placental inflammation and elevated levels of IL-6, TNF-α, or ICAM-1 was associated with an increased risk for microcephaly.ConclusionCompared with a single hit, two inflammatory hits are associated with stronger risk for abnormal cranial ultrasound, spastic cerebral palsy, and microcephaly at 2 years.

Viral Infection Sensitizes Human Fetal Membranes to Bacterial Lipopolysaccharide by MERTK Inhibition and Inflammasome Activation

Chorioamnionitis, premature rupture of fetal membranes (FMs), and subsequent preterm birth are associated with local infection and inflammation, particularly IL-1β production. Although bacterial infections are commonly identified, other microorganisms may play a role in the pathogenesis. Because viral pandemics, such as influenza, Ebola, and Zika, are becoming more common, and pregnant women are at increased risk for associated complications, this study evaluated the impact that viral infection had on human FM innate immune responses. This study shows that a herpes viral infection of FMs sensitizes the tissue to low levels of bacterial LPS, giving rise to an exaggerated IL-1β response. Using an ex vivo human FM explant system and an in vivo mouse model of pregnancy, we report that the mechanism by which this aggravated inflammation arises is through the inhibition of the TAM receptor, MERTK, and activation of the inflammasome. The TAM receptor ligand, growth arrest specific 6, re-establishes the normal FM response to LPS by restoring and augmenting TAM receptor and ligand expression, as well as by preventing the exacerbated IL-1β processing and secretion. These findings indicate a novel mechanism by which viruses alter normal FM immune responses to bacteria, potentially giving rise to adverse pregnancy outcomes.

Extremely low gestational age and very low birthweight for gestational age are risk factors for autism spectrum disorder in a large cohort study of 10-year-old children born at 23-27 weeks' gestation

BACKGROUND

No prospective cohort study of high-risk children has used rigorous exposure assessment and optimal diagnostic procedures to examine the perinatal antecedents of autism spectrum disorder separately among those with and without cognitive impairment.

OBJECTIVE

We sought to identify perinatal factors associated with increased risk for autism spectrum disorder with and without intellectual disability (intelligence quotient <70) in children born extremely preterm.

STUDY DESIGN

This prospective multicenter (14 institutions in 5 states) birth cohort study included children born at 23-27 weeks' gestation in 2002 through 2004 who were evaluated for autism spectrum disorder and intellectual disability at age 10 years. Pregnancy information was obtained from medical records and by structured maternal interview. Cervical-vaginal "infection" refers to maternal report of bacterial infection (n = 4), bacterial vaginosis (n = 30), yeast infection (n = 62), mixed infection (n = 4), or other/unspecified infection (n = 43; eg, chlamydia, trichomonas, or herpes). We do not know the extent to which infection per se was confirmed by microbial colonization. We use the terms "fetal growth restriction" and "small for gestational age" interchangeably in light of the ongoing challenge to discern pathologically from constitutionally small newborns. Severe fetal growth restriction was defined as a birthweight Z-score for gestational age at delivery <-2 (ie, ≥2 SD below the median birthweight in a referent sample that excluded pregnancies delivered for preeclampsia or fetal indications). Participants were classified into 4 groups based on whether or not they met rigorous diagnostic criteria for autism spectrum disorder and intellectual disability (autism spectrum disorder+/intellectual disability-, autism spectrum disorder+/intellectual disability+, autism spectrum disorder-/intellectual disability+, and autism spectrum disorder-/intellectual disability-). Temporally ordered multinomial logistic regression models were used to examine the information conveyed by perinatal factors about increased risk for autism spectrum disorder and/or intellectual disability (autism spectrum disorder+/intellectual disability-, autism spectrum disorder+/intellectual disability+, and autism spectrum disorder-/intellectual disability+).

RESULTS

In all, 889 of 966 (92%) children recruited were assessed at age 10 years, of whom 857 (96%) were assessed for autism spectrum disorder; of these, 840 (98%) children were assessed for intellectual disability. Autism spectrum disorder+/intellectual disability- was diagnosed in 3.2% (27/840), autism spectrum disorder+/intellectual disability+ in 3.8% (32/840), and autism spectrum disorder-/intellectual disability+ in 8.5% (71/840). Maternal report of presumed cervical-vaginal infection during pregnancy was associated with increased risk of autism spectrum disorder+/intellectual disability+ (odds ratio, 2.7; 95% confidence interval, 1.2-6.4). The lowest gestational age category (23-24 weeks) was associated with increased risk of autism spectrum disorder+/intellectual disability+ (odds ratio, 2.9; 95% confidence interval, 1.3-6.6) and autism spectrum disorder+/intellectual disability- (odds ratio, 4.4; 95% confidence interval, 1.7-11). Severe fetal growth restriction was strongly associated with increased risk for autism spectrum disorder+/intellectual disability- (odds ratio, 9.9; 95% confidence interval, 3.3-30), whereas peripartum maternal fever was uniquely associated with increased risk of autism spectrum disorder-/intellectual disability+ (odds ratio, 2.9; 95% confidence interval, 1.2-6.7).

CONCLUSION

Our study confirms that low gestational age is associated with increased risk for autism spectrum disorder irrespective of intellectual ability, whereas severe fetal growth restriction is strongly associated with autism spectrum disorder without intellectual disability. Maternal report of cervical-vaginal infection is associated with increased risk of autism spectrum disorder with intellectual disability, and peripartum maternal fever is associated with increased risk for intellectual disability without autism spectrum disorder.

Antenatal glucocorticoids and neonatal inflammation-associated proteins

BACKGROUND

To date, studies of the relationship between antenatal glucocorticoids (AGC) and neonatal inflammation in preterm newborns have been largely limited to umbilical cord blood specimens.

AIM

To explore the association between exposure to antenatal glucocorticoids and concentrations of inflammation-related proteins in whole blood collected from very preterm newborns at multiple times during the first postnatal month.

METHODS

We measured the protein concentrations on postnatal day 1 (N=1118), day 7 (N=1138), day 14 (N=1030), day 21 (N=936) and day 28 (N=877) from infants born before the 28th week of gestation and explored the relationship between antenatal steroid receipt and protein concentrations in the highest and lowest quartiles. The creation of multinomial logistic regression models (adjusted for potential confounders) allowed us calculate odds ratios and 95% confidence intervals.

RESULTS

Twenty of 420 assessments [21 (proteins)×2 (exposure levels: partial and full)×2 (quartile levels: top and bottom)×5 (days)] were statistically significant without any cohesive pattern.

CONCLUSION

Among infants born before 28 weeks of gestational age, neither full, nor partial courses of antenatal glucocorticoids have a sustained anti-inflammatory effect.

The antecedents and correlates of necrotizing enterocolitis and spontaneous intestinal perforation among infants born before the 28th week of gestation

OBJECTIVE

To identify antecedents of "medical" necrotizing enterocolitis (mNEC), "surgical" NEC (sNEC), and spontaneous intestinal perforation (SIP) in newborns delivered before 28 weeks gestation.

STUDY DESIGN

Prospective multicenter cohort study. During study period, 2002- 2004, women delivering before 28 weeks gestation at one of 14 participating institutions were enrolled. Well defined antenatal and postnatal variables were collected. Bivariate analyses were performed to identify candidates for developing multinomial multivariable time-oriented logistic regression models.

RESULTS

Of the 1320 infants, 5% had mNEC, 6% had sNEC, and 4% had SIP. Antecedents of mNEC included mother's identification as Black, consumption of aspirin during the pregnancy, and vaginal bleeding after the 12th week of gestation. For sNEC the antecedents were maternal self- support, obesity and anemia during the pregnancy, birth before the 24th week, birth weight ≤750gm, and receipt of fresh frozen plasma (FFP) during the first postnatal week. An infant was at increased risk of SIP if the placenta had increased syncytial knots, birth occurred before the 24th week, and received FFP during the first week.

CONCLUSIONS

Maternal and neonatal characteristics might help identify at-risk ELGANs for NEC and SIP, who then may potentially benefit from targeted preventive strategies.

The Development of Extremely Preterm Infants Born to Women Who Had Genitourinary Infections During Pregnancy

Gestational genitourinary infections, which have been associated with neurodevelopmental impairments among infants born near term, have not been studied among very preterm infants. The mothers of 989 infants born before 28 weeks of gestation were interviewed about urine, bladder, or kidney infections (UTIs) and cervical or vaginal infections (CVIs) during pregnancy, as well as other exposures and characteristics, and their charts were reviewed for the Extremely Low Gestational Age Newborns (ELGAN) Study (2002-2004). At 2 years of age, these infants underwent a neurodevelopmental assessment. Generalized estimating equation logistic regression models of developmental adversities were used to adjust for potential confounders. Infants born to women who reported a UTI were less likely than were others to have a very low Mental Development Index (adjusted odds ratio = 0.5; 95% confidence interval: 0.3, 0.8), whereas infants born to women who reported a CVI were more likely than others to have a low Psychomotor Development Index (adjusted odds ratio = 1.7; 95% confidence interval: 1.04, 2.7). In this high-risk sample, maternal gestational CVI, but not UTI, was associated with a higher risk of impaired motor development at 2 years of age. The apparent protective effect of UTI might be spurious, reflect confounding due to untreated asymptomatic bacteriuria among women who were not given a diagnosis of UTI, or reflect preconditioning.

[Microbiological diagnosis of bacterial infection associated with delivery and postpartum]

The newborn may acquire infections during delivery due to maternal colonization of the birth canal, by microorganisms such as Streptococcus agalactiae that caused early neonatal infection, or acquisition through the placenta, amniotic fluid or birth products. After birth, the newborn that needs hospitalization can develop nosocomial infections during their care and exceptionally through lactation by infectious mastitis or incorrect handling of human milk, which does not require to stop breastfeeding in most cases. It is important and necessary to perform microbiological diagnosis for the correct treatment of perinatal infections, especially relevant in preterm infants with low or very low weight with high mortality rates.

Correlation between Clinical, Placental Histology and Microbiological Findings in Spontaneous Preterm Births

AIMS

To examine the occurrence of chorioamnionitis and abruption among women who had a spontaneous preterm birth (SPTB), the correlation between clinical and placental findings, and the impact of these complications on neonatal outcome after delivery.

METHODS

This was a retrospective case-control study conducted between 2008 and 2012 at a single teaching hospital. The study group included all women who had an SPTB (23-36 weeks). Placentas were cultured and underwent histological examination.

RESULTS

A total of 478 women were included. The mean gestational age at delivery was 32.6 ± 3.1 weeks. Overall, 260 (54.4%) women had either clinical and/or histological abruption or chorioamnionitis. Clinical chorioamnionitis was diagnosed before birth in 14 (2.9%) women, while histological chorioamnionitis (HCA) in 84 (17.4%). Overall, 38 neonates had infection. Placental cultures were negative in 65.8% (25/38) of these neonates, and in 77.1% (27/38), HCA was ruled out. Logistic regression analysis revealed that neonatal morbidity and mortality were correlated with gestational age at delivery (p = 0.02), not with placental pathology (p = 0.08).

CONCLUSIONS

Half of the women with PTB had clinical or histological abruption, chorioamnionitis or both. A partial correlation was found between clinical and placental findings. The main determinant of neonatal outcome was gestational age at delivery and not placental findings.

Antecedents and correlates of visual field deficits in children born extremely preterm

AIM

We sought to identify the antecedents and correlates of visual field deficits (VFDs) at age 2 years among infants born before the 28th week of gestation.

METHODS

The visual fields of 1023 infants were assessed by confrontation at age 2 years. We compared the ante-and postnatal characteristics and exposures of the 65 infants with a VFD to their peers who did not have a VFD. We used time-oriented logistic regression risk models to assess the associations of potential antecedents and correlates with a VFD.

RESULTS

In the final regression model, VFD was associated with maternal consumption of aspirin during the current pregnancy, recurring/persistent acidemia during the first 3 postnatal days, cerebral ventriculomegaly seen on neonatal ultrasound, prethreshold retinopathy of prematurity (ROP), and supplemental oxygen and ventilator dependence at 36 weeks post-menstrual age. Birth before the 27th week was also associated with increased risk, but its significance was diminished by the addition of postnatal variables.

CONCLUSION

In this sample of extremely preterm born infants, antenatal as well as early and late postnatal characteristics and exposures are associated with an increased risk of having a VFD. Our study adds to our knowledge about the complex etiology of visual deficits of prematurity, and supports a multifactorial cause of these deficits.

Antenatal and early postnatal antecedents of parent-reported attention problems at 2 years of age

OBJECTIVES

To assess antenatal and early postnatal antecedents of attention problems identified by the Child Behavior Checklist in extremely preterm children.

STUDY DESIGN

In a cohort of 826 children born between 23 and 27 weeks' gestation, we collected demographic, birth, and postnatal information. We then identified behavior problems by using parent ratings from the Child Behavior Checklist at 2 years' adjusted age. We created time-oriented logistic regression risk models to identify significant risk factors for attention problems and Diagnostic and Statistical Manual of Mental Disorders-compatible attention deficit/hyperactivity problems (ADHP(DSM)).

RESULTS

Children were at increased risk of both attention problems if they were born to a woman who had no formal education beyond high school and/or a woman who was exposed to secondhand smoke. Recovery of a single organism from the placenta was associated with increased risk of an attention problem, and fetal stem vessel thrombosis and recovery of Mycoplasma species were associated with increased risk of ADHP(DSM). Infants of multifetal gestations were at reduced risk of both attention problems. The only postnatal risk factor for an attention problem was recovery of bacteria from a tracheal aspirate.

CONCLUSION

Among extremely preterm infants, several potentially modifiable antenatal and perinatal antecedents are associated with increased risk for attention problems and ADHP(DSM) at 2 years adjusted age.

Escherichia coli-induced temporal and differential secretion of heat-shock protein 70 and interleukin-1β by human fetal membranes in a two-compartment culture system

INTRODUCTION

Escherichia coli is recognized as an etiological bacteria associated with chorioamnionitis and the preterm premature rupture of fetal membranes. This pathological condition induces pro-inflammatory cytokines and degradative metalloproteinases, which are considered biological markers secreted in an acute stage of infection. Heat-shock proteins (HSPs) are an important component of the innate immunity response and are found in different pathological conditions. They have not been previously measured in human fetal membranes in response to infectious conditions. We hypothesized that the choriodecidual tissue and amniotic epithelium secreted temporal and differential Hsp-60, Hsp-70, and interleukin (IL)-1β mediated by E. coli infection.

METHODS

Fetal membranes were mounted in a two-compartment culture system and infected with two passes of live E. coli at different doses (10², 10⁴, 10⁵, and 10⁶ colony-forming units (CFU)/mL) and intervals of incubation (3, 6, and 24 h). The culture medium was collected, and Hsp-60, Hsp-70, and IL-1β were assessed using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

After 3 and 6 h of infection, E. coli induced an increase in Hsp-70 secretion in the choriodecidual tissue. However, after 24 h of incubation, Hsp-70 was downregulated and we observed an increase in IL-1β secretion. By contrast, E. coli induced a lower Hsp-60 secretion in the amnion compared to Hsp-70.

DISCUSSION

Human fetal membranes responded actively to E. coli infection, with an increase in Hsp-70 during the first hours of infection. After 24 h, there was an increase in the liberation of IL-1β.

Systemic inflammation in the extremely low gestational age newborn following maternal genitourinary infections

PROBLEM

Gestational genitourinary infections are associated with lifelong disabilities, but it is unknown if neonatal inflammation is involved.

METHOD

Mothers of 914 infants born before 28th gestation week reported cervical/vaginal infection (CVI), and/or urine/bladder/kidney infection (UTI), or neither. Inflammation proteins measured in baby's blood on postnatal days 1, 7, and 14 were considered elevated if in the top quartile for gestational age. Logistic regression models adjusting for potential confounders assessed odds ratios.

RESULTS

Compared to mothers with neither UTI/CVI, those with CVI were more likely to have infants with elevated CRP, SAA, MPO, IL-1β, IL-6, IL-6R, TNF-α, RANTES, ICAM-3, E-selectin, and VEGF-R2 on day 1; those with UTI were more likely to have infants with elevated MPO, IL-6R, TNF-R1, TNF-R2, and RANTES on day 7. Placental anaerobes and genital mycoplasma were more common in pregnancies with CVI.

CONCLUSION

Gestational UTI/CVI should be targeted for preventing systemic inflammation in the very preterm newborn.

Prevalence and clinical significance of sterile intra-amniotic inflammation in patients with preterm labor and intact membranes

PROBLEM

Inflammation and infection play a major role in preterm birth. The purpose of this study was to (i) determine the prevalence and clinical significance of sterile intra-amniotic inflammation and (ii) examine the relationship between amniotic fluid (AF) concentrations of high mobility group box-1 (HMGB1) and the interval from amniocentesis to delivery in patients with sterile intra-amniotic inflammation.

METHOD OF STUDY

AF samples obtained from 135 women with preterm labor and intact membranes were analyzed using cultivation techniques as well as broad-range PCR and mass spectrometry (PCR/ESI-MS). Sterile intra-amniotic inflammation was defined when patients with negative AF cultures and without evidence of microbial footprints had intra-amniotic inflammation (AF interleukin-6 ≥ 2.6 ng/mL).

RESULTS

(i) The frequency of sterile intra-amniotic inflammation was significantly greater than that of microbial-associated intra-amniotic inflammation [26% (35/135) versus 11% (15/135); (P = 0.005)], (ii) patients with sterile intra-amniotic inflammation delivered at comparable gestational ages had similar rates of acute placental inflammation and adverse neonatal outcomes as patients with microbial-associated intra-amniotic inflammation, and (iii) patients with sterile intra-amniotic inflammation and high AF concentrations of HMGB1 (≥8.55 ng/mL) delivered earlier than those with low AF concentrations of HMGB1 (P = 0.02).

CONCLUSION

(i) Sterile intra-amniotic inflammation is more frequent than microbial-associated intra-amniotic inflammation, and (ii) we propose that danger signals participate in sterile intra-amniotic inflammation in the setting of preterm labor.

Early blood gas predictors of bronchopulmonary dysplasia in extremely low gestational age newborns

Aim. To determine among infants born before the 28th week of gestation to what extent blood gas abnormalities during the first three postnatal days provide information about the risk of bronchopulmonary dysplasia (BPD). Methods. We studied the association of extreme quartiles of blood gas measurements (hypoxemia, hyperoxemia, hypocapnea, and hypercapnea) in the first three postnatal days, with bronchopulmonary dysplasia, among 906 newborns, using multivariable models adjusting for potential confounders. We approximated NIH criteria by classifying severity of BPD on the basis of the receipt of any O2 on postnatal day 28 and at 36 weeks PMA and assisted ventilation. Results. In models that did not adjust for ventilation, hypoxemia was associated with increased risk of severe BPD and very severe BPD, while infants who had hypercapnea were at increased risk of very severe BPD only. In contrast, infants who had hypocapnea were at reduced risk of severe BPD. Including ventilation for 14 or more days eliminated the associations with hypoxemia and with hypercapnea and made the decreased risk of very severe BPD statistically significant. Conclusions. Among ELGANs, recurrent/persistent blood gas abnormalities in the first three postnatal days convey information about the risk of severe and very severe BPD.

Lenticulostriate vasculopathy in extremely low gestational age newborns: Inter-rater variability of cranial ultrasound readings, antecedents and postnatal characteristics

Although lenticulostriate vasculopathy (LSV) was first detected on a cranial ultrasound nearly 30 years ago, its clinical implications and significance remain unknown. The objective of this study was to evaluate the inter-rater reliability of cranial ultrasound readings of LSV, and to explore relationships with potential antecedents and developmental correlates in extremely low gestational age newborns. Of the 1506 infants enrolled during the years 2002-2004, 1450 had at least one set of ultrasound scans evaluated for LSV and 939 had all three sets. To evaluate the inter-rater agreement for identifying LSV, we compared readings from two independent radiologists on days 1-4, 5-14, and on or after day 15. We then evaluated the relationships between LSV and maternal, antenatal, and postnatal characteristics. Our results showed that kappa values were 0.18, 0.33, and 0.36 on days 1-4, days 5-14, and day 15 or greater. Infants who were identified as LSV positive by two readers had higher Score for Neonatal Acute Physiology-II (an illness severity indicator), higher rates of tracheal infection and bacteremia, lower partial pressure of arterial oxygen and pH levels on 2 of the first 3 postnatal days, and they were more likely to have a lower psycho-motor development index at age 2 years. Positive agreement on the presence of LSV was low, as was the kappa value, an index of inter-rater reliability. Infants with high illness severity scores and their correlates were at increased risk of developing LSV, while those who develop LSV appear to be at increased risk of motor dysfunction.

Genitourinary pathogens and preterm birth

PURPOSE OF REVIEW

The aim is to describe and quantify the association between genitourinary tract infections and preterm birth.

RECENT FINDINGS

Recent studies confirm the importance of identifying and treating both asymptomatic and symptomatic bacteriuria in pregnancy, which is reflected in current antenatal screening guidelines. These guidelines do not recommend routine screening for other asymptomatic lower genital infections (bacterial vaginosis, trichomonas and gonorrhoea) reflecting inconsistent study results, which may reflect differences in study design, size, diagnostics and the timing of screening in pregnancy. Screening for group B Streptococcus (GBS) late in pregnancy is recognized to reduce neonatal disease, but there is a striking lack of robust studies, specifically randomized controlled trials (RCTs), considering the effect of GBS screening earlier in pregnancy on adverse pregnancy outcomes.

SUMMARY

The potential for screening and treatment of genitourinary tract infections in pregnancy to reduce preterm birth rates has been demonstrated in some RCTs. Current guidelines do not reflect these data because of inconsistencies across the body of evidence. There is a need for robust RCTs to confirm or refute earlier data, to inform the optimal timing for screening in pregnancy and to better quantify the contribution of individual infections to the burden of preterm birth.

Histologic chorioamnionitis as a consideration in the management of newborns of febrile mothers

INTRODUCTION

Chorioamnionitis (CA) presents a risk for neonatal sepsis, but its diagnosis remains a challenge. Maternal fever is often used as a clinical predictor of infection, but may be affected by other factors. There is no consensus among neonatologists regarding the length of treatment of babies born to febrile mothers with negative blood culture, but whose placentas are positive for the presence of histologic CA (HCA).

OBJECTIVES

A prospective observational cohort study was conducted on term infants to determine the association of HCA with C-reactive protein (CRP) and elevated immature/total neutrophil (I/T) ratio and other perinatal factors.

METHODS

I/T ratio, CRP, blood culture and placental pathology were performed on 100 infants born to mothers with temperature ≥ 100.4 °F. Placental pathology performed on 100 control infants born to afebrile mothers.

RESULTS

There was a significant association between HCA and maternal fever (MF). The presence of elevated CRP was associated with HCA. There was no significant association between HCA and anesthesia, mode of delivery, nor elevated I/T ratio.

CONCLUSIONS

Maternal fever is associated with HCA. The HCA in conjunction with an elevated CRP can guide the duration of antimicrobial therapy in infants born to febrile mothers.

Identification of intracellular bacteria in the basal plate of the human placenta in term and preterm gestations

OBJECTIVE

Bacteria have been identified in different regions of the placenta. Here, we tested the hypothesis that the maternal basal plate of the placenta harbors microbes that may be associated with adverse pregnancy outcomes.

STUDY DESIGN

We performed a cross-sectional study of pregnancies from a single tertiary care hospital. Maternal medical and obstetric characteristics were obtained and pregnancies followed up prospectively for outcomes and placental collection. After delivery, systematic random sampling of the placental basal plate was performed. Paraffin sections of basal plates were stained with 4 histologic stains and scored for morphological evidence of bacteria.

RESULTS

Of 195 total patients in the study, Gram-positive and -negative intracellular bacteria of diverse morphologies were documented in the basal plates of 27% of all placentas. Of the patients, 35% delivered preterm. No difference was noted between placental basal plates from preterm or term gestations. Intracellular bacteria were found in the placental basal plates of 54% spontaneous preterm deliveries <28 weeks, and in 26% of term spontaneous deliveries (P = .02). Intracellular bacteria were also documented in placentas without clinical or pathologic chorioamnionitis.

CONCLUSION

A total of 27% of placentas demonstrated intracellular bacteria in the placental basal plate using morphological techniques. Thus, the maternal basal plate is a possible source of intrauterine colonization and placental pathological examination could include examination for bacteria in this important maternal-fetal interface.

Inflammation-initiating illnesses, inflammation-related proteins, and cognitive impairment in extremely preterm infants

Neonatal inflammation is associated with perinatal brain damage. We evaluated to what extent elevated blood levels of inflammation-related proteins supplement information about the risk of impaired early cognitive function provided by inflammation-related illnesses. From 800 infants born before the 28th week of gestation, we collected blood spots on days 1, 7 and 14, for analysis of 25 inflammation-related proteins, and data about culture-positive bacteremia, necrotizing enterocolitis (Bell stage IIIb), and isolated perforation of the intestine, during the first two weeks, and whether they were ventilated on postnatal day 14. We considered a protein to be persistently or recurrently elevated if its concentration was in the top quartile (for gestational age and day blood was collected) on two separate days one week apart. We assessed the children at 2 years of age with the Bayley Mental Development Index (MDI). The combinations of NEC and ventilation on day 14, and of bacteremia and ventilation on day 14 consistently provided information about elevated risk of MDI <55, regardless of whether or not a variable for an elevated protein concentration was included in the model. A variable for a persistently or recurrently elevated concentration of each of the following proteins provided additional information about an increased risk of MDI <55: CRP, SAA, IL-6, TNF-alpha, IL-8, MIP-1beta, ICAM-1, E-SEL, and IGFBP-1. We conclude that elevated blood concentrations of inflammation-related proteins provide information about the risk of impaired cognitive function at age 2 years that supplements information provided by inflammation-associated illnesses.

Brain damage in preterm newborns and maternal medication: the ELGAN Study

OBJECTIVE

We sought to evaluate the association between maternal medication use during pregnancy and cerebral white matter damage and cerebral palsy (CP) among very preterm infants.

STUDY DESIGN

This analysis of data from the Extremely Low Gestational Age Newborns (ELGAN) Study included 877 infants born <28 weeks' gestation. Mothers were interviewed, charts were reviewed, placentas were cultured and assessed histologically, and children were evaluated at 24 months corrected age. A diagnostic algorithm classified neurologic findings as quadriparetic CP, diparetic CP, hemiparetic CP, or no CP.

RESULTS

After adjustment for the potential confounding of disorders for which medications might have been indicated, the risk of quadriparetic CP remained elevated among the infants of mothers who consumed aspirin (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.3-6.9) and nonsteroidal antiinflammatory drugs (NSAIDs) (OR, 2.4; 95% CI, 1.04-5.8). The risk of diparetic CP was also associated with maternal consumption of an NSAID, but only if the consumption was not approved by a physician (OR, 3.5; 95% CI 1.1-11.0).

CONCLUSION

The possibility that aspirin and NSAID use in pregnancy could lead to perinatal brain damage cannot be excluded.

Acute histologic chorioamnionitis at term: nearly always noninfectious

Background

The link between histologic acute chorioamnionitis and infection is well established in preterm deliveries, but less well-studied in term pregnancies, where infection is much less common.

Methodology/Principal Findings

We conducted a secondary analysis among 195 low-risk women with term pregnancies enrolled in a randomized trial. Histologic and microbiologic evaluation of placentas included anaerobic and aerobic cultures (including mycoplasma/ureaplasma species) as well as PCR. Infection was defined as ≥1,000 cfu of a single known pathogen or a ≥2 log difference in counts for a known pathogen versus other organisms in a mixed culture. Placental membranes were scored and categorized as: no chorioamnionitis, Grade 1 (subchorionitis and patchy acute chorioamnionitis), or Grade 2 (severe, confluent chorioamnionitis). Grade 1 or grade 2 histologic chorioamnionitis was present in 34% of placentas (67/195), but infection was present in only 4% (8/195). Histologic chorioamnionitis was strongly associated with intrapartum fever >38°C [69% (25/36) fever, 26% (42/159) afebrile, P<.0001]. Fever occurred in 18% (n = 36) of women. Most febrile women [92% (33/36)] had received epidural for pain relief, though the association with fever was present with and without epidural. The association remained significant in a logistic regression controlling for potential confounders (OR = 5.8, 95% CI = 2.2,15.0). Histologic chorioamnionitis was also associated with elevated serum levels of interleukin-8 (median = 1.3 pg/mL no histologic chorioamnionitis, 1.5 pg/mL Grade 1, 2.1 pg/mL Grade 2, P = 0.05) and interleukin-6 (median levels = 2.2 pg/mL no chorioamnionitis, 5.3 pg/mL Grade 1, 24.5 pg/mL Grade 2, P = 0.02) at admission for delivery as well as higher admission WBC counts (mean = 12,000cells/mm³ no chorioamnionitis, 13,400cells/mm³ Grade 1, 15,700cells/mm³ Grade 2, P = 0.0005).

Conclusion/Significance

Our results suggest histologic chorioamnionitis at term most often results from a noninfectious inflammatory process. It was strongly associated with fever, most of which was related to epidural used for pain relief. A more ‘activated’ maternal immune system at admission was also associated with histologic chorioamnionitis.