Colonization of second-trimester placenta parenchyma

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.

Placental Infection With Ureaplasma species Is Associated With Histologic Chorioamnionitis and Adverse Outcomes in Moderately Preterm and Late-Preterm Infants

OBJECTIVE

The human Ureaplasma species are the microbes most frequently isolated from placentae of women who deliver preterm. The role of Ureaplasma species has been investigated in pregnancies at <32 weeks of gestation, but currently no studies have determined the prevalence of ureaplasmas in moderately preterm and late-preterm (hereafter, "moderate/late preterm") infants, the largest cohort of preterm infants.

METHODS

Women delivering moderate/late preterm infants (n = 477) and their infants/placentae (n = 535) were recruited, and swab specimens of chorioamnion tissue, chorioamnion tissue specimens, and cord blood specimens were obtained at delivery. Swab and tissue specimens were cultured and analyzed by 16S ribosomal RNA polymerase chain reaction (PCR) for the presence of microorganisms, while cord blood specimens were analyzed for the presence of cytokines, chemokines, and growth factors.

RESULTS

We detected microorganisms in 10.6% of 535 placentae (443 were delivered late preterm and 92 were delivered at term). Significantly, Ureaplasma species were the most prevalent microorganisms, and their presence alone was associated with histologically confirmed chorioamnionitis in moderate/late preterm and term placentae (P < .001). The presence of ureaplasmas in the chorioamnion was also associated with elevated levels of granulocyte colony-stimulating factor (P = .02).

CONCLUSIONS

These findings have important implications for infection and adverse pregnancy outcomes throughout gestation and should be of major consideration for obstetricians and neonatologists.

The heritability of gestational age in a two-million member cohort: implications for spontaneous preterm birth

Preterm birth (PTB), defined as birth prior to a gestational age (GA) of 37 completed weeks, affects more than 10% of births worldwide. PTB is the leading cause of neonatal mortality and is associated with a broad spectrum of lifelong morbidity in survivors. The etiology of spontaneous PTB (SPTB) is complex and has an important genetic component. Previous studies have compared monozygotic and dizygotic twin mothers and their families to estimate the heritability of SPTB, but these approaches cannot separate the relative contributions of the maternal and the fetal genomes to GA or SPTB. Using the Utah Population Database, we assessed the heritability of GA in more than 2 million post-1945 Utah births, the largest familial GA dataset ever assembled. We estimated a narrow-sense heritability of 13.3% for GA and a broad-sense heritability of 24.5%. A maternal effect (which includes the effect of the maternal genome) accounts for 15.2% of the variance of GA, and the remaining 60.3% is contributed by individual environmental effects. Given the relatively low heritability of GA and SPTB in the general population, multiplex SPTB pedigrees are likely to provide more power for gene detection than will samples of unrelated individuals. Furthermore, nongenetic factors provide important targets for therapeutic intervention.

The preterm placental microbiome varies in association with excess maternal gestational weight gain

OBJECTIVE

Although a higher maternal body mass index is associated with preterm birth, it is unclear whether excess gestational weight gain (GWG) or obesity drives increased risk. We and others have shown that the placenta harbors microbiota, which is significantly different among preterm births. Our aim in this study was to investigate whether the preterm placental microbiome varies by virtue of obesity or alternately by excess GWG.

STUDY DESIGN

Placentas (n=320) were collected from term and preterm pregnancies. Genomic DNA was extracted and subjected to metagenomic sequencing. Data were analyzed by clinical covariates that included the 2009 Institute of Medicine's GWG guideline and obesity.

RESULTS

Analysis of 16S recombinant RNA-based metagenomics revealed no clustering of the microbiome by virtue of obesity (P=.161). Among women who spontaneously delivered preterm, there was again no clustering by obesity (P=.480), but there was significant clustering by excess GWG (P=.022). Moreover, among preterm births, detailed analysis identified microbial genera (family and genus level) and bacterial metabolic gene pathways that varied among pregnancies with excess GWG. Notably, excess GWG was associated with decreased microbial folate biosynthesis pathways and decreased butanoate metabolism (linear discriminate analysis, >3.0-fold).

CONCLUSION

Although there were no significant alterations in the microbiome by virtue of obesity per se, excess GWG was associated with an altered microbiome and its metabolic profile among those women who experienced a preterm birth.

The perinatal microbiome and pregnancy: moving beyond the vaginal microbiome

The human microbiome, the collective genome of the microbial community that is on and within us, has recently been mapped. The initial characterization of healthy subjects has provided investigators with a reference population for interrogating the microbiome in metabolic, intestinal, and reproductive health and disease states. Although it is known that bacteria can colonize the vagina, recent metagenomic studies have shown that the vaginal microbiome varies among reproductive age women. Similarly, the richness and diversity of intestinal microbiota also naturally fluctuate among gravidae in both human and nonhuman primates, as well as mice. Moreover, recent evidence suggests that microbiome niches in pregnancy are not limited to maternal body sites, as the placenta appears to harbor a low biomass microbiome that is presumptively established in early pregnancy and varies in association with a remote history of maternal antenatal infection as well as preterm birth. In this article, we will provide a brief overview on metagenomics science as a means to investigate the microbiome, observations pertaining to both variation and the presumptive potential role of a varied microbiome during pregnancy, and how future studies of the microbiome in pregnancy may lend to a better understanding of human biology, reproductive health, and parturition.

The Maternal Serological Response to Intrauterine Ureaplasma sp. Infection and Prediction of Risk of Pre-Term Birth

Pre-term birth (PTB) associated with intrauterine infection and inflammation (IUI) is the major cause of early PTB less than 32 weeks of gestation. Ureaplasma spp. are common commensals of the urogenital tract in pregnancy and are the most commonly identified microorganisms in amniotic fluid of pre-term pregnancies. While we have an understanding of the causal relationship between intra-amniotic infection, inflammation and PTB, we are still unable to explain why vaginal Ureaplasma sp. colonization is tolerated in some women but causes PTB in others. It is now known that placental tissues are frequently colonized by bacteria even in apparently healthy pregnancies delivered at term; usually this occurs in the absence of a significant local inflammatory response. It appears, therefore, that the site, nature, and magnitude of the immune response to infiltrating microorganisms are key in determining pregnancy outcome. Some evidence exists that the maternal serological response to Ureaplasma sp. colonization may be predictive of adverse pregnancy outcome, although issues such as the importance of virulence factors (serovars) and the timing, magnitude, and functional consequences of the immune response await clarification. This mini-review discusses the evidence linking the maternal immune response to risk of PTB and the potential applications of maternal serological analysis for predicting obstetric outcome.

Microorganisms in the female genital tract during pregnancy: tolerance versus pathogenesis

Microorganisms in the pregnant female genital tract are not always associated with pathology. The factors that influence the maternal response to microorganisms remain ill defined. We review the state of knowledge of microbe-host interactions in gestational tissues and highlight mechanisms that promote tolerance or pathogenesis. Tolerance to microorganisms is promoted during pregnancy by several mechanisms including upregulation of anti-inflammatory mediators, induction of endotoxin tolerance, and possibly by regulation of autophagy. Conversely, an altered vaginal microbiota or a pre-existing viral presence may result in induction of excessive inflammation and preterm labor. Although infections play a prevalent role in preterm birth, microbes are present in gestational tissues of women with healthy outcomes and may provide beneficial functions. The complex interactions between different microbial species and the maternal immune system during gestation remain incompletely elucidated.

The effect of conditioned medium derived from human placental multipotent mesenchymal stromal cells on neutrophils: possible implications for placental infection

The role of human placental multipotent mesenchymal stromal cells (hPMSCs) in placental inflammation is unknown. We hypothesize that hPMSCs are involved in the early phases of placental infection. hPMSCs were isolated from term placentas and neutrophils from peripheral blood. The expression of toll-like receptors (TLRs) and cytokines by hPMSCs was determined by RT-PCR, flow cytometry and enzyme-linked immunosorbent assay. The effect of conditioned medium of hPMSCs with or without lipopolysaccharide (LPS) pretreatment on neutrophil functions: migration, apoptosis and production of reactive oxygen species (ROS) was assessed by flow cytometry and western blot. hPMSCs expressed TLR1, TLR3, TLR4, TLR6, TLR7 and TLR9. LPS stimulation increased the expression of TLR4 and the production of IL-6 and IL-8 by hPMSCs. Neutrophils exhibited chemotaxis to hPMSC-conditioned medium, which was inhibited by IL-8 depletion. Neutrophil CD11b activation was promoted by hPMSC-conditioned medium, which was further enhanced in media from hPMSCs pretreated with LPS. hPMSC-conditioned medium reduced neutrophil ROS production. Neutrophil phagocytosis was increased by LPS alone but not by hPMSC-conditioned medium with or without LPS stimulation. hPMSC-conditioned medium induced STAT3 activation in neutrophils, which was inhibited by neutralizing antibody to IL-6. hPMSC-conditioned medium rescued neutrophils from apoptosis, but this effect was significantly reduced in conditioned medium of hPMSCs with LPS pretreatment. Depletion of IL-6 from the conditioned medium further inhibited the anti-apoptotic effect on neutrophils. Our results demonstrate that hPMSCs can interact with peripheral blood neutrophils in response to inflammatory signals of the placenta. Cytokines produced by hPMSCs can induce neutrophil chemotaxis and reduce neutrophil apoptosis.

Risk of cerebral palsy in relation to pregnancy disorders and preterm birth: a national cohort study

AIM

To assess the risk of developing cerebral palsy in relation to pregnancy disorders and preterm birth.

METHOD

By linking the Medical Birth Registry of Norway to other national registries, we identified all live births in Norway from 1967 through to 2001. Risks of cerebral palsy (CP) after preterm delivery and pregnancy disorders were estimated in different gestational age groups.

RESULT

In total, 1 764 509 children delivered at 23 to 43 weeks' gestation were included. The prevalence of CP was 1.8 per 1000 births. Absolute risk of CP was 8.5% among children born at 23 to 27 weeks' gestation, 5.6% at 28 to 30 weeks, 2.0% at 31 to 33 weeks, 0.4% at 34 to 36 weeks, and 0.1% thereafter. Placental abruption, chorioamnionitis, prolonged rupture of membranes, intrauterine growth restriction, pre-eclampsia, multiple births, placenta previa, bleeding, cervical conization, and congenital malformation were all associated with CP. Before 32 weeks' gestation, absolute risk of CP was highest with chorioamnionitis (9.1%) and lowest with pre-eclampsia (3.1%). Among those born after 31 weeks, the absolute risk of CP was more consistently (but also more slightly) increased with a recorded pregnancy disorder.

INTERPRETATION

Early delivery and pregnancy disorders were both strong risk factors for CP. The added risks with recorded pregnancy disorders varied within categories of gestational age.

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.

Meconium microbiome analysis identifies bacteria correlated with premature birth

Background

Preterm birth is the second leading cause of death in children under the age of five years worldwide, but the etiology of many cases remains enigmatic. The dogma that the fetus resides in a sterile environment is being challenged by recent findings and the question has arisen whether microbes that colonize the fetus may be related to preterm birth. It has been posited that meconium reflects the in-utero microbial environment. In this study, correlations between fetal intestinal bacteria from meconium and gestational age were examined in order to suggest underlying mechanisms that may contribute to preterm birth.

Methods

Meconium from 52 infants ranging in gestational age from 23 to 41 weeks was collected, the DNA extracted, and 16S rRNA analysis performed. Resulting taxa of microbes were correlated to clinical variables and also compared to previous studies of amniotic fluid and other human microbiome niches.

Findings

Increased detection of bacterial 16S rRNA in meconium of infants of <33 weeks gestational age was observed. Approximately 61·1% of reads sequenced were classified to genera that have been reported in amniotic fluid. Gestational age had the largest influence on microbial community structure (R = 0·161; p = 0·029), while mode of delivery (C-section versus vaginal delivery) had an effect as well (R = 0·100; p = 0·044). Enterobacter, Enterococcus, Lactobacillus, Photorhabdus, and Tannerella, were negatively correlated with gestational age and have been reported to incite inflammatory responses, suggesting a causative role in premature birth.

Interpretation

This provides the first evidence to support the hypothesis that the fetal intestinal microbiome derived from swallowed amniotic fluid may be involved in the inflammatory response that leads to premature birth.

Chorioamnionitis in the pathogenesis of brain injury in preterm infants

Chorioamnionitis (or placental infection) is suspected to be a risk factor for brain injury in premature infants. The suggested association between chorioamnionitis and cystic periventricular leukomalacia and cerebral palsy is uncertain because of the variability of study designs and definitions of chorioamnionitis. Improvements in neonatal intensive care may have attenuated the impact of chorioamnionitis on brain health outcomes. Large multicenter studies using rigorous definitions of chorioamnionitis on placental pathologies and quantitative magnetic resonance techniques may offer the optimal way to clarify the complex role of chorioamnionitis in modifying brain health and long-term outcomes.

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.

Clinical dilemma of positive histologic chorioamnionitis in term newborn

BACKGROUND

Although histologic chorioamnionitis (HCA) is known to be associated with poor outcomes in preterm infants, its clinical significance among term infants is not clearly known.

OBJECTIVES

To investigate the utility of HCA in determining early onset clinical sepsis (EOCS) among term newborns.

METHODS

The incidence of HCA and EOCS in term infants born during 2008-2009 was evaluated in a single center retrospective study (n = 3417). The predictive value of HCA for determining EOCS in term infants admitted to the neonatal intensive care unit (NICU) for suspected sepsis (n = 388) was quantified. Outcome of otherwise healthy term infants in the nursery with HCA was also investigated.

RESULTS

Overall, 11% of term infants with HCA also had EOCS. HCA was associated with increased risk for EOCS (OR 2.6, 95% confidence interval 1.6-4.2, P < 0.001) among term infants admitted to the NICU for suspected sepsis. No cases of EOCS were found among otherwise well-appearing infants in the nursery with HCA. Multiple logistic regression analysis indicated that addition of HCA does not increase the power of a model combining C-reactive protein (CRP) and immature to total neutrophil ratio in determining EOCS.

CONCLUSION

Although HCA in term infants is associated with EOCS, it did not improve the ability of CRP and immature to total neutrophil ratio to predict EOCS. Routine placental examination may not contribute to the diagnosis of EOCS in term infants.

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.

Antibiotic Therapy for Premature Rupture of Membranes and Preterm Labor and Effect on Fetal Outcome

In Germany almost 10 % of children are born before the end of 37th week of gestation. In at least one quarter of these cases, ascending infection of the vagina plays a causative role, particularly during the early weeks of gestation. If, in addition to the decidua, the amniotic membrane, amniotic fluid and the umbilical cord are also affected, infection not only triggers uterine contractions and premature rupture of membranes but also initiates a systemic inflammatory reaction on the part of the fetus, which can increase neonatal morbidity. Numerous studies and meta-analyses have found that antibiotic therapy prolongs pregnancy and reduces neonatal morbidity. No general benefit of antibiotic treatment was found for premature uterine contractions. But it is conceivable that a subgroup of pregnant women would benefit from antibiotic treatment. It is important to identify this subgroup of women and offer them targeted treatment. This overview summarizes the current body of evidence on antibiotic treatment for impending preterm birth and the effect on neonatal outcomes.

Perinatal systemic inflammatory responses of growth-restricted preterm newborns

AIM

To compare the early post-natal pattern of systemic inflammation in growth-restricted infants born before the 28th week of gestation to that of appropriately grown peers.

METHODS

We measured the concentrations of 25 inflammation-related proteins in blood spots collected from 939 newborns during the first 2 post-natal weeks. We calculated the odds ratios (99% confidence intervals) that concentrations would be in the highest quartile.

RESULTS

Severely growth-restricted infants (birth weight Z-score <-2) were not at increased risk of systemic inflammation shortly after birth. On post-natal day 14, however, they were significantly more likely than their peers to have a CRP, IL-1β, IL-6, TNF-α, IL-8, MCP-4, ICAM-1, ICAM-3, E-SEL, MMP-9, VEGF-R2 and/or IGFBP-1 concentration in the highest quartile. These increased risks could not be attributed to delivery indication, bacteremia or duration of ventilation.

CONCLUSION

Growth-restricted preterm newborns appear to be at increased risk of elevated concentrations of inflammation-associated proteins by post-natal day 14.

The interaction of classical complement component C1 with parasite and host calreticulin mediates Trypanosoma cruzi infection of human placenta

Background

9 million people are infected with Trypanosoma cruzi in Latin America, plus more than 300,000 in the United States, Canada, Europe, Australia, and Japan. Approximately 30% of infected individuals develop circulatory or digestive pathology. While in underdeveloped countries transmission is mainly through hematophagous arthropods, transplacental infection prevails in developed ones.

Methodology/Principal Findings

During infection, T. cruzi calreticulin (TcCRT) translocates from the endoplasmic reticulum to the area of flagellum emergence. There, TcCRT acts as virulence factor since it binds maternal classical complement component C1q that recognizes human calreticulin (HuCRT) in placenta, with increased parasite infectivity. As measured ex vivo by quantitative PCR in human placenta chorionic villi explants (HPCVE) (the closest available correlate of human congenital T. cruzi infection), C1q mediated up to a 3–5-fold increase in parasite load. Because anti-TcCRT and anti-HuCRT F(ab′)₂ antibody fragments are devoid of their Fc-dependent capacity to recruit C1q, they reverted the C1q-mediated increase in parasite load by respectively preventing its interaction with cell-bound CRTs from both parasite and HPCVE origins. The use of competing fluid-phase recombinant HuCRT and F(ab′)₂ antibody fragments anti-TcCRT corroborated this. These results are consistent with a high expression of fetal CRT on placental free chorionic villi. Increased C1q-mediated infection is paralleled by placental tissue damage, as evidenced by histopathology, a damage that is ameliorated by anti-TcCRT F(ab′)₂ antibody fragments or fluid-phase HuCRT.

Conclusions/Significance

T. cruzi infection of HPCVE is importantly mediated by human and parasite CRTs and C1q. Most likely, C1q bridges CRT on the parasite surface with its receptor orthologue on human placental cells, thus facilitating the first encounter between the parasite and the fetal derived placental tissue. The results presented here have several potential translational medicine aspects, specifically related with the capacity of antibody fragments to inhibit the C1q/CRT interactions and thus T. cruzi infectivity.

The Trypanosoma cruzi protozoan infects 9 million people in Latin America and increasing numbers in North America, Europe, Australia, and Japan. It is an important neglected parasitic disease in the Americas with no safe treatment available. One third of those infected develops incapacitating pathology. While in poor countries transmission of the parasite is mainly through blood feeding insects, transplacental infection is increasingly important in developed regions. Herein we show that T. cruzi calreticulin (TcCRT), a multifunctional protein, exteriorized by the parasite, mediates infection of human placenta, since it binds human complement component C1, a “danger signal” detector. (Complement is an innate immune defense system, with more than 40 plasma or membrane-bound proteins). However, in a parasite strategy, maternal C1 is utilized to infect placenta. Fetal calreticulin (HuCRT) is also easily detectable in placental tissues that are in direct contact with maternal blood. Thus, C1q by bridging parasite and HuCRT mediates high increases in cultured placental tissue infection with damaging consequences. Complete reversion of C1-mediated infection and a decreased placental damage, is observed in the presence of anti-TcCRT and anti-HuCRT antibody fragments, or fluid-phase competing HuCRT. It remains to be determined whether these mechanisms also operate in other intracellular protozoa.

Systemic inflammation associated with severe intestinal injury in extremely low gestational age newborns

To define the role of systemic inflammation in infants with intestinal perforation (IP) and necrotizing enterocolitis (NEC), we measured 25 blood protein concentrations on days 1, 7 and 14 in 939 infants born before 28 weeks' gestation. On days 7 and 14, infants with NEC had elevated levels of C-reactive protein (CRP), serum amyloid A (SAA), IL-6 and IL-8. Infants with IP had elevated levels of CRP and insulin growth factor binding protein-1 on day 7 and elevated CRP, SAA, TNF-receptor-2 and matrix metalloproteinase-9 levels on day 14. A better understanding of systemic inflammation might help prevent and treat these disorders.

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.

Lipopolysaccharide-preconditioning protects against endotoxin-induced white matter injury in the neonatal rat brain

BACKGROUND

Exposing the brain to a sub-damaging stimulus can protect against a subsequent lethal insult, a phenomenon termed preconditioning. The aim of this study was to investigate the neuroprotective effect of low dose LPS (lipopolysaccharide) pretreatment in endotoxin induced periventricular leukomalacia (PVL) in a rat model.

METHODS

Wistar rats with dated pregnancies were allocated to 5 groups: (i) no LPS administered, intraperitoneally (i.p.) pyrogen-free saline injected (Control group), (ii) 500μg/kg LPS administrated i.p. on days 18 and 19 (PVL group), (iii) 50μg/kg LPS administrated i.p. on day 17 followed by 500μg/kg LPS i.p. on days 18 and 19 (PC-PVL group), (iv) 50μg/kg LPS administrated on day 17 (PC only), and (v) i.p. pyrogen-free saline injected control group on day 17.

RESULTS

LPS-preconditioning given 24h before potent LPS exposure significantly reduced the number of apoptotic cell deaths and prevented hypomyelination. Antioxidant enzyme gene expression levels (Superoxide Dismutase-SOD1, SOD2, and SOD3) were increased and Tumor Necrosis Factor (TNF)α expression levels were decreased in the PC+PVL group when compared with the PVL group.

CONCLUSION

Low-dose LPS given one day before potent doses of LPS reduces antepartum LPS-induced brain damage. The mechanisms of protection might involve oxidation and inflammation.

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.

Fetal-placental inflammation, but not adrenal activation, is associated with extreme preterm delivery

OBJECTIVE

Spontaneous labor at term involves the activation of placental corticotropin-releasing hormone and the fetal adrenal axis, but the basis for extreme preterm labor is unknown. Our objective was to determine whether placental corticotropin-releasing hormone is activated in extreme preterm labor.

STUDY DESIGN

One thousand five hundred six mothers delivering at less than 28 weeks' gestation were enrolled. Each mother/infant pair was assigned to the category that described the primary reason for hospitalization. Observers who had no knowledge of patient categorization assessed placenta microbiology, histology, and corticotropin-releasing hormone expression. These were correlated with the primary reason for hospitalization.

RESULTS

Among infants delivered at less than 28 weeks' gestation, spontaneous (vs induced) delivery was associated with less placental corticotropin-releasing hormone expression and more frequent signs of placental inflammation and infection.

CONCLUSION

Inflammation and infection, rather than premature activation of the fetal adrenal axis, should be the major focus of research to prevent extremely preterm human birth.

Microbiota of the upper and lower genital tract

Our understanding of the bacterial species inhabiting the female genital tract has been limited primarily by our ability to detect them. Early investigations using microscopy and culture-based techniques identified lactobacilli as the predominant members of the vaginal microbiota and suggested that these organisms might serve a protective function at the mucosal surface. Improvements in cultivation techniques and the development of molecular-based detection strategies validated these early findings and enabled us to recognize that the microbiota of the female genital tract is much more complex than previously suspected. Disruption of the vaginal microbial community due to invasion of exogenous organisms or by overgrowth of one or more endogenous species has important health implications for both the mother and newborn.

Prokineticin 1 induces inflammatory response in human myometrium: a potential role in initiating term and preterm parturition

The infiltration of human myometrium and cervix with leukocytes and the formation of a pro-inflammatory environment within the uterus have been associated with the initiation of both term and preterm parturition. The mechanism regulating the onset of this pro-inflammatory cascade is not fully elucidated. We demonstrate that prokineticin 1 (PROK1) is up-regulated in human myometrium and placenta during labor. The expression of PROK1 receptor remains unchanged during labor and is abundantly expressed in the myometrium. Gene array analysis identified 65 genes up-regulated by PROK1 in human myometrium, mainly cytokines and chemokines, including IL-1β, chemokine C-C motif ligand 3, and colony-stimulating factor 3. In addition, we demonstrate that PROK1 increases the expression of chemokine C-C motif ligand 20, IL-6, IL-8, prostaglandin synthase 2, and prostaglandin E(2) and F(2α) secretion. The treatment of myometrial explants with 100 ng/mL of lipopolysaccharide up-regulates the expression of PROK1, PROK1 receptor, and inflammatory mediators. The infection of myometrial explants with lentiviral microRNA targeting PROK1, preceding treatment with lipopolysaccharide, reduces the expression of inflammatory genes. We propose that PROK1 is a novel inflammatory mediator that can contribute to the onset of human parturition at term and partially mediate premature onset of inflammatory pathways during bacterial infection.

Placenta microbiology and histology and the risk for severe retinopathy of prematurity

PURPOSE

To test the hypothesis that the presence of bacteria and/or histologic inflammation in the placenta of infants born preterm is associated with an increased risk for severe retinopathy of prematurity (ROP).

METHODS

This was a prospective cohort study. Exploratory and multivariable data analyses were used, including logistic regression models with interaction terms. Main outcomes were four definitions of severe ROP: stage 3 or higher, any ROP in zone I, prethreshold/threshold, and plus disease.

RESULTS

Individually, placenta bacteria and histologic inflammation were not associated with severe ROP in univariable analyses among 1064 infants with gestational age <28 weeks or among 715 infants with gestational age <27 weeks (we excluded infants with a gestational age of 27 weeks because of the very small number of ROP cases). However, the co-occurrence of bacteria and inflammation was associated with an increased risk for ROP in zone I (odds ratio, 3.1; 95% confidence interval, 1.02-9.5). Among 339 infants with any placental bacteria, the co-occurrence of (1) inflammation and a gestational age of 23 to 24 weeks and (2) inflammation and hyperoxia were associated with prominent increases in risk for all definitions of severe ROP.

CONCLUSIONS

While antenatal exposure to infection or inflammation alone does not appear to convey risk information for severe ROP, their co-occurrence does. This finding supports the hypothesis that a fetal inflammatory response to antenatal infection might be part of the etiology of severe ROP.

Necrotizing enterocolitis is associated with ureaplasma colonization in preterm infants

The study objective was to determine whether Ureaplasma respiratory tract colonization of preterm infants <33 wk gestation is associated with an increased risk for necrotizing enterocolitis (NEC). One or more tracheal or nasopharyngeal aspirates for Ureaplasma culture and PCR were obtained during the first week of life from 368 infants <33 wk gestation enrolled from 1999 to 2003 or from 2007 to 2009. NEC Bell stage ≥ 2 was confirmed by radiological criteria, and pathology, if available. Cord serum samples were analyzed for IL-6 and IL-1β concentrations, and placentas were reviewed for histological chorioamnionitis in the first cohort. NEC was confirmed in 29 of 368 (7.9%) of the combined cohorts. The incidence of NEC was 2.2-fold higher in Ureaplasma-positive (12.3%) than Ureaplasma-negative (5.5%) infants <33 wk (OR, 2.43; 95% CI, 1.13-5.2; p = 0.023) and 3.3-fold higher in Ureaplasma-positive (14.6%) than Ureaplasma-negative (4.4%) infants ≤ 28 wk (OR, 3.67; 95% CI, 1.36-9.93; p = 0.01). Age of onset, hematologic parameters at onset, and NEC severity were similar between Ureaplasma-positive and negative infants. Cord serum IL-6 and IL-1β concentrations were significantly higher in Ureaplasma-positive than in Ureaplasma-negative NEC-affected infants. Ureaplasma may be a factor in NEC pathogenesis in preterm infants by contributing to intestinal mucosal injury and/or altering systemic or local immune responses.

Maternal microbe-specific modulation of inflammatory response in extremely low-gestational-age newborns

The fetal response to intrauterine inflammatory stimuli appears to contribute to the onset of preterm labor as well as fetal injury, especially affecting newborns of extremely low gestational age. To investigate the role of placental colonization by specific groups of microorganisms in the development of inflammatory responses present at birth, we analyzed 25 protein biomarkers in dry blood spots obtained from 527 newborns delivered by Caesarean section in the 23rd to 27th gestation weeks. Bacteria were detected in placentas and characterized by culture techniques. Odds ratios for having protein concentrations in the top quartile for gestation age for individual and groups of microorganisms were calculated. Mixed bacterial vaginosis (BV) organisms were associated with a proinflammatory pattern similar to those of infectious facultative anaerobes. Prevotella and Gardnerella species, anaerobic streptococci, peptostreptococci, and genital mycoplasmas each appeared to be associated with a different pattern of elevated blood levels of inflammation-related proteins. Lactobacillus was associated with low odds of an inflammatory response. This study provides evidence that microorganisms colonizing the placenta provoke distinctive newborn inflammatory responses and that Lactobacillus may suppress these responses.

Despite improved intensive care, preterm and especially extremely low-gestation-age neonates continue to be at a considerably increased risk of morbidity, mortality, and developmental problems. The fetal inflammatory response appears to contribute to the onset of preterm labor, fetal injury, and complications, underlying lifetime health challenges facing these children. This study provides evidence that bacterial colonization of the very preterm placenta is associated with distinct microorganism-specific inflammatory protein profiles in the newborn blood specimens. We also provide evidence that Lactobacillus reduces inflammatory responses in newborns. Our data support the concept that targeting of placental colonization by specific drugs or probiotics during early pregnancy holds promise for preventing not only preterm birth but also subsequent and long-lasting, inflammation-provoked late sequelae.

Presumed and definite bacteremia in extremely low gestational age newborns

AIM

To explore risk patterns for presumed and definite, early and late neonatal bacteremia.

METHODS

We studied 1106 extremely low gestational age newborns who survived until postnatal day 28. We defined early definite bacteremia as a positive bacterial culture in the first week and definite late bacteremia as a positive bacterial culture in week 2, 3 or 4. Bacteremia was presumed if antibiotics were given for more than 72 h despite negative blood cultures.

RESULTS

Risk patterns did not differ much for presumed and definite bacteremia in the first postnatal month. While maternal and pregnancy characteristics were associated with early bacteremia, neonatal comorbidities, especially NEC, were the main antecedents/correlates of late bacteremia. All four categories of bacteremia were associated with younger gestational age and lower birth weight. Infants with presumed and definite bacteremia had similar distributions of days of ventilation and oxygenation.

CONCLUSION

Definite and presumed late bacteremias have rather similar risk patterns, while those of early and late bacteremia differ appreciably.

Blood gases and retinopathy of prematurity: the ELGAN Study

OBJECTIVE

This study tested the hypothesis that preterm infants who had a blood gas derangement on at least 2 of the first 3 postnatal days are at increased risk for more severe retinopathy of prematurity (ROP).

METHOD

1,042 infants born before 28 weeks' gestational age (GA) were included. An infant was considered to be exposed if his/her blood gas measure was in the highest or lowest quartile for GA on at least 2 of the first 3 postnatal days.

RESULTS

Multivariable models adjusting for confounders indicate that exposure to a PCO(2) in the highest quartile predicts ROP (stage 3, 4 or 5: OR = 1.6, 95% CI = 1.1-2.3); zone 1: 2.0, 1.1-3.6; prethreshold/threshold: 1.9, 1.2-3.0; plus disease: 1.8, 1.1-2.9). Estimates are similar for a low pH for zone 1 (2.1, 1.2-3.8), prethreshold/threshold (1.8, 1.1-2.8), but did not quite achieve statistical significance for ROP stage 3, 4, or 5 (1.4, 0.9-2.0) and plus disease (1.5, 0.9-2.4). A PaO(2) in the highest quartile for GA on at least 2 of the first 3 postnatal days was associated with a doubling of the risk of ROP in zone 1 (2.5, 1.4-4.4) and of prethreshold/threshold disease (2.1, 1.4-3.3), a 70% risk increase for plus disease (1.7, 1.04-2.8), while a 40% risk increase for ROP stage 3 or higher did not achieve statistical significance (1.4, 0.96-2.0).

CONCLUSION

Infants exposed to high PCO(2), low pH and high PaO(2) appear to be at increased risk of more severe ROP.

Recent advances in understanding the microbiology of the female reproductive tract and the causes of premature birth

Data derived from molecular microbiological investigations of the human vagina have led to the discovery of resident bacterial communities that exhibit marked differences in terms of species composition. All undergo dynamic changes that are likely due to intrinsic host and behavioral factors. Similar types of bacteria have been found in both amniotic fluid and the vagina, suggesting a potential route of colonization. Given that not all of the species involved in intrauterine infections are readily cultivated, it is important that culture-independent methods of analysis must be used to understand the etiology of these infections. Further research is needed to establish whether an ascending pathway from the vagina to the amniotic cavity enables the development of intrauterine infections.

Early blood gas abnormalities and the preterm brain

The authors explored associations between blood gas abnormalities in more than 1,000 preterm infants during the first postnatal days and indicators of neonatal brain damage. During 2002-2004, women delivering infants before 28 weeks' gestation at one of 14 participating institutions in 5 US states were asked to enroll in the study. The authors compared infants with blood gas values in the highest or lowest quintile for gestational age and postnatal day (extreme value) on at least 1 of the first 3 postnatal days with the remainder of the subjects, with separate analyses for blood gas abnormalities on multiple days and for partial pressure of oxygen in the alveolar gas of <35. Outcomes analyzed were ventriculomegaly and an echolucent lesion on an ultrasound scan in the neonatal intensive care unit, and cerebral palsy, microcephaly, and a low score on a Bayley Scale of Infant Development at 24 months. Every blood gas derangement (hypoxemia, hyperoxemia, hypocapnia, hypercapnia, and acidosis) was associated with multiple indicators of brain damage. However, for some, the associations were seen with only 1 day of exposure; others were evident with 2 or more days' exposure. Findings suggest that individual blood gas derangements do not increase brain damage risk. Rather, the multiple derangements associated with indicators of brain damage might be indicators of immaturity/vulnerability and illness severity.

Factors associated with small head circumference at birth among infants born before the 28th week

OBJECTIVE

We sought to identify risk factors for congenital microcephaly in extremely low gestational age newborns.

STUDY DESIGN

Demographic, clinical, and placental characteristics of 1445 infants born before the 28th week were gathered and evaluated for their relationship with congenital microcephaly.

RESULTS

Almost 10% of newborns (n = 138), rather than the expected 2.2%, had microcephaly defined as a head circumference >2 SD below the median. In multivariable models, microcephaly was associated with nonwhite race, severe intrauterine growth restriction, delivery for preeclampsia, placental infarction, and being female. The risk factors for a head circumference between <1 and >2 SD below the median were similar to those of microcephaly.

CONCLUSION

Characteristics associated with fetal growth restriction and preeclampsia are among the strongest correlates of microcephaly among children born at extremely low gestational ages. The elevated risk of a small head among nonwhites and females might reflect the lack of appropriate head circumference standards.

Antenatal antecedents of a small head circumference at age 24-months post-term equivalent in a sample of infants born before the 28th post-menstrual week

BACKGROUND

Little is known about the antecedents of microcephaly in early childhood among children born at extremely low gestational age.

AIM

To identify some of the antecedents of microcephaly at age two years among children born before the 28th week of gestation.

STUDY DESIGN

Observational cohort study.

SUBJECTS

1004 infants born before the 28th week of gestation.

OUTCOME MEASURES

Head circumference Z-scores of <-2 and >or=-2, <-1.

RESULTS

Risk of microcephaly and a less severely restricted head circumference decreased monotonically with increasing gestational age. After adjusting for gestational age and other potential confounders, the risk of microcephaly at age 2 years was increased if microcephaly was present at birth [odds ratio: 8.8 ((95% confidence interval: 3.7, 21)], alpha hemolytic Streptococci were recovered from the placenta parenchyma [2.9 (1.2, 6.9)], the child was a boy [2.8 (1.6, 4.9)], and the child's mother was not married [2.5 (1.5, 4.3)]. Antecedents associated not with microcephaly, but with a less extreme reduction in head circumference were recovery of Propionibacterium sp from the placenta parenchyma [2.9 (1.5, 5.5)], tobacco exposure [2.0 (1.4, 3.0)], and increased syncytial knots in the placenta [2.0 (1.2, 3.2)].

CONCLUSIONS

Although microcephaly at birth predicts a small head circumference at 2 years among children born much before term, pregnancy and maternal characteristics provide supplemental information about the risk of a small head circumference years later. Two findings appear to be novel. Tobacco exposure during pregnancy, and organisms recovered from the placenta predict reduced head circumference at age two years.

Inflammation-induced preterm birth in a murine model is associated with increases in fetal macrophages and circulating erythroid precursors

The presence of intrauterine inflammation has been associated with adverse neurologic outcomes in preterm infants, but the precise mechanisms of fetal brain injury remain unclear. We sought to evaluate inflammatory cell trafficking, fetal organ damage, and molecular regulation in the fetoplacental unit using an established mouse model of preterm birth associated with intrauterine inflammation. Gestational sacs were harvested 6 hours after intrauterine infusion of saline or lipopolysaccharide (LPS). Histologic, immunohistochemical, and molecular investigations were performed to identify target organ damage and the cellular phenotype of inflammatory cells and to quantify circulating inflammatory and hematopoietic mediators within the placental and fetal tissue. There was widespread increase in fetal macrophages in LPS-exposed pups, including within the leptomeninges of the brain, associated with significantly higher of interleukin 6 levels in LPS-exposed pups. Although no specific central nervous system injury (necrosis or apoptosis) was documented, liver hematomas were seen significantly more frequently in LPS-exposed pups. Circulating nucleated fetal erythrocytes were also present more frequently with LPS exposure without significantly higher erythropoietin levels than saline-exposed mice. The presence of increased macrophages, increased circulating interleukin 6 levels, and increased circulating erythroid precursors in LPS-exposed pups suggests that these are significant factors associated with potential target organ damage, such as liver hematomas, associated with intrauterine inflammation and preterm birth. The role of macrophages within the fetal leptomeninges is unclear, but they may play an important role in inflammatory-mediated brain damage, and further investigation of their significance and potential as therapeutic targets is warranted.

Detection of ureaplasmas by the polymerase chain reaction in the amniotic fluid of patients with cervical insufficiency

AIMS

The purpose of this study was to determine the clinical significance of detecting microbial footprints of ureaplasmas in amniotic fluid (AF) using specific primers for the polymerase chain reaction (PCR) in patients presenting with cervical insufficiency.

METHODS

Amniocentesis was performed in 58 patients with acute cervical insufficiency (cervical dilatation, > or =1.5 cm) and intact membranes, and without regular contractions (gestational age, 16-29 weeks). AF was cultured for aerobic and anaerobic bacteria as well as genital mycoplasmas. Ureaplasmas (Ureaplasma urealyticum and Ureaplasma parvum) were detected by PCR using specific primers. Patients were divided into three groups according to the results of AF culture and PCR for ureaplasmas: those with a negative AF culture and a negative PCR (n=44), those with a negative AF culture and a positive PCR (n=10), and those with a positive AF culture regardless of PCR result (n=4).

RESULTS

1) Ureaplasmas were detected by PCR in 19.0% (11/58) of patients, by culture in 5.2% (3/58), and by culture and/or PCR in 22.4% (13/58); 2) Among the 11 patients with a positive PCR for ureaplasmas, the AF culture was negative in 91% (10/11); 3) Patients with a negative AF culture and a positive PCR for ureaplasmas had a significantly higher median AF matrix metalloproteinase-8 (MMP-8) concentration and white blood cell (WBC) count than those with a negative AF culture and a negative PCR (P<0.001 and P<0.05, respectively); 4) Patients with a positive PCR for ureaplasmas but a negative AF culture had a higher rate of spontaneous preterm birth within two weeks of amniocentesis than those with a negative AF culture and a negative PCR (P<0.05 after adjusting for gestational age at amnio-centesis); 5) Of the patients who delivered within two weeks of amniocentesis, those with a positive PCR for ureaplasmas and a negative AF culture had higher rates of histologic amnionitis and funisitis than those with a negative AF culture and a negative PCR (P<0.05 after adjusting for gestational age at amniocentesis, for each); 6) However, no significant differences in the intensity of the intra-amniotic inflammatory response and perinatal outcome were found between patients with a positive AF culture and those with a negative AF culture and a positive PCR.

CONCLUSIONS

1) Cultivation techniques for ureaplasmas did not detect most cases of intra-amniotic infection caused by these microorganisms (91% of cases with cervical insufficiency and microbial footprints for ureaplasmas in the amniotic cavity had a negative AF culture); 2) Patients with a negative AF culture and a positive PCR assay were at risk for intra-amniotic and fetal inflammation as well as spontaneous preterm birth.

Microbiologic and histologic characteristics of the extremely preterm infant's placenta predict white matter damage and later cerebral palsy. the ELGAN study

Inflammatory phenomena seem to contribute to the occurrence of perinatal cerebral white matter damage and CP. The stimulus that initiates the inflammation remains obscure. One thousand two hundred forty-six infants born before the 28th postmenstrual week had a protocol ultrasound scan of the brain read concordantly by two independent sonologists. Eight hundred ninety-nine of the children had a neurologic examination at approximately 24-mo postterm equivalent. The placenta of each child had been biopsied under sterile conditions and later cultured. Histologic slides of the placenta were examined specifically for this study. Recovery of a single microorganism predicted an echolucent lesion, whereas polymicrobial cultures and recovery of skin flora predicted both ventriculomegaly and an echolucent lesion. Diparetic CP was predicted by recovery of a single microorganism, multiple organisms, and skin flora. Histologic inflammation predicted ventriculomegaly and diparetic CP. The risk of ventriculomegaly associated with organism recovery was heightened when accompanied by histologic inflammation, but the risk of diparetic CP was not. Low-virulence microorganisms isolated from the placenta, including common skin microflora, predict ultrasound lesions of the brain and diparetic CP in the very preterm infant. Organism recovery does not seem to be needed for placenta inflammation to predict diparetic CP.

Reduced mortality and increased BPD with histological chorioamnionitis and leukocytosis in very-low-birth-weight infants

OBJECTIVE

To investigate the association between leukocytosis, mortality and bronchopulmonary dysplasia (BPD) in very-low-birth-weight infants (VLBW) born to mothers with histological chorioamnionitis.

STUDY DESIGN

A retrospective cohort study from a single level 3 neonatal intensive care unit. The study sample included infants born to mothers with histological chorioamnionitis (n=252). Total white blood cells (WBCs) after birth were measured. Leukocytosis was defined as a total WBC count >30 000 per mm(3) in the first 2 days of life. Outcomes investigated included BPD and death. Both unadjusted and multivariable analyses were carried out.

RESULT

After controlling for potential confounding variables, infants who developed a leukocytosis after birth had increased odds of BPD (4.6, 95% confidence interval (95% CI): 2.0 to 10.3), but decreased odds of death (0.3, 95% CI: 0.1 to 0.90).

CONCLUSION

In our population of VLBW infants born to mothers with histological chorioamnionitis, leukocytosis after birth is associated with a decrease in mortality but an increase in BPD.

The ELGAN study of the brain and related disorders in extremely low gestational age newborns

BACKGROUND

Extremely low gestational age newborns (ELGANs) are at increased risk for structural and functional brain abnormalities.

AIM

To identify factors that contribute to brain damage in ELGANs.

STUDY DESIGN

Multi-center cohort study.

SUBJECTS

We enrolled 1506 ELGANs born before 28 weeks gestation at 14 sites; 1201 (80%) survived to 2 years corrected age. Information about exposures and characteristics was collected by maternal interview, from chart review, microbiologic and histological examination of placentas, and measurement of proteins in umbilical cord and early postnatal blood spots.

OUTCOME MEASURES

Indicators of white matter damage, i.e. ventriculomegaly and echolucent lesions, on protocol cranial ultrasound scans; head circumference and developmental outcomes at 24 months adjusted age, i.e., cerebral palsy, mental and motor scales of the Bayley Scales of Infant Development, and a screen for autism spectrum disorders.

RESULTS

ELGAN Study publications thus far provide evidence that the following are associated with ultrasongraphically detected white matter damage, cerebral palsy, or both: preterm delivery attributed to preterm labor, prelabor premature rupture of membranes, or cervical insufficiency; recovery of microorganisms in the placenta parenchyma, including species categorized as human skin microflora; histological evidence of placental inflammation; lower gestational age at delivery; greater neonatal illness severity; severe chronic lung disease; neonatal bacteremia; and necrotizing enterocolitis.

CONCLUSIONS

In addition to supporting a potential role for many previously identified antecedents of brain damage in ELGANs, our study is the first to provide strong evidence that brain damage in extremely preterm infants is associated with microorganisms in placenta parenchyma.

Fetal inflammatory response and brain injury in the preterm newborn

Preterm birth can be caused by intrauterine infection and maternal/fetal inflammatory responses. Maternal inflammation (chorioamnionitis) is often followed by a systemic fetal inflammatory response characterized by elevated levels of proinflammatory cytokines in the fetal circulation. The inflammation signal is likely transmitted across the blood-brain barrier and initiates a neuroinflammatory response. Microglial activation has a central role in this process and triggers excitotoxic, inflammatory, and oxidative damage in the developing brain. Neuroinflammation can persist over a period of time and sensitize the brain to subinjurious insults in early and chronic phases but may offer relative tolerance in the intermediate period through activation of endogenous anti-inflammatory, protective, and repair mechanisms. Neuroinflammatory injury not only destroys what exists but also changes what develops.

Fetal growth restriction and chronic lung disease among infants born before the 28th week of gestation

OBJECTIVE

Improvement in survival of extremely premature infants over the past several decades has resulted in an increase in the number of infants with chronic lung disease (CLD). Historical neonatal exposures associated with CLD now less frequently precede the disease. There is now increasing interest in exposures and events before delivery that predict CLD. The objective of this study was to identify current prenatal predictors of CLD.

METHODS

We collected data about prenatal, placental, and neonatal characteristics of 1241 newborns who were delivered before completion of the 28th week of gestation. Associations between prenatal factors, microbiologic and histologic characteristics of the placenta, and selected neonatal characteristics and CLD risk were first evaluated in univariate analyses. Subsequent multivariate analyses investigated the contribution of prenatal factors, particularly fetal growth restriction (FGR), to CLD risk.

RESULTS

Among the prenatal factors, birth weight z scores, used as a marker of FGR, provided the most information about CLD risk. Indicators of placental inflammation and infection were not associated with increased risk of CLD. Within nearly all strata of prenatal, placental, and neonatal variables, growth-restricted infants were at increased CLD risk, compared with infants who were not growth-restricted. FGR was the only maternal or prenatal characteristic that was highly predictive of CLD after adjustment for other risk factors.

CONCLUSIONS

FGR is independently associated with the risk of CLD. Thus, factors that control fetal somatic growth may have a significant impact on vulnerability to lung injury and in this way increase CLD risk.