Is chorioamnionitis harmful for the brain of preterm infants? A clinical overview

Is chorioamnionitis associated with hearing impairment in preterm infants? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

It has been reported that chorioamnionitis (CA) could increase the risk of hearing impairment in premature infants, but results are inconsistent. A meta-analysis was performed to systematically evaluate the relationship between CA and hearing impairment in premature infants.

MATERIAL AND METHODS

Search in PubMed, Embase, Cochrane Library from their inception to May 2020. We concluded all cohort and case-control studies which explored the associations between CA and hearing impairment in preterm infants. Pregnant women with other infections besides CA were excluded. PRISMA guidelines were followed. Fixed-and random-effects models were used, depending on heterogeneity. And we performed to calculate odds ratio (ORs), and 95% CIs using fixed-effects models.

RESULTS

Seven studies involving 4134 premature infants were included. There was non-significant association between CA and hearing impairment (adjusted OR 1.43, 95% CI 0.99 to 2.04, P = 0.05; heterogeneity: I² = 13%, P = 0.33).

CONCLUSION

This article concludes that CA is not a risk factor for hearing impairment in premature infants, but most of the current studies are retrospective studies with low intensity and lack of high-quality articles to discuss it.

The dimensions of white matter injury in preterm neonates

White matter injury (WMI) represents a frequent form of parenchymal brain injury in preterm neonates. Several dimensions of WMI are recognized, with distinct neuropathologic features involving a combination of destructive and maturational anomalies. Hypoxia-ischemia is the main mechanism leading to WMI and adverse white matter development, which result from injury to the oligodendrocyte precursor cells. Inflammation might act as a potentiator for WMI. A combination of hypoxia-ischemia and inflammation is frequent in several neonatal comorbidities such as postnatal infections, NEC and bronchopulmonary dysplasia, all known contributors to WMI. White matter injury is an important predictor of adverse neurodevelopmental outcomes. When WMI is detected on neonatal brain imaging, a detailed characterization of the injury (pattern of injury, severity and location) may enhance the ability to predict outcomes. This clinically-oriented review will provide an overview of the pathophysiology and imaging diagnosis of the multiple dimensions of WMI, will explore the association between postnatal complications and WMI, and will provide guidance on the signification of white matter anomalies for motor and cognitive development.

Placental Pathology Findings and the Risk of Intraventricular and Cerebellar Hemorrhage in Preterm Neonates

Placental pathology as a predisposing factor to intraventricular hemorrhage remains a matter of debate, and its contribution to cerebellar hemorrhage development is still largely unexplored. Our study aimed to assess placental and perinatal risk factors for intraventricular and cerebellar hemorrhages in preterm infants. This retrospective cohort study included very low-birth weight infants born at the Gaslini Children's Hospital between January 2012 and October 2016 who underwent brain magnetic resonance with susceptibility-weighted imaging at term-equivalent age and whose placenta was analyzed according to the Amsterdam Placental Workshop Group Consensus Statement. Of the 286 neonates included, 68 (23.8%) had intraventricular hemorrhage (all grades) and 48 (16.8%) had a cerebellar hemorrhage (all grades). After correction for gestational age, chorioamnionitis involving the maternal side of the placenta was found to be an independent risk factor for developing intraventricular hemorrhage, whereas there was no association between maternal and fetal inflammatory response and cerebellar hemorrhage. Among perinatal factors, we found that intraventricular hemorrhage was significantly associated with cerebellar hemorrhage (odds ratio [OR], 8.14), mechanical ventilation within the first 72 h (OR, 2.67), and patent ductus arteriosus requiring treatment (OR, 2.6), whereas cesarean section emerged as a protective factor (OR, 0.26). Inotropic support within 72 h after birth (OR, 5.24) and intraventricular hemorrhage (OR, 6.38) were independent risk factors for cerebellar hemorrhage, whereas higher gestational age was a protective factor (OR, 0.76). Assessing placental pathology may help in understanding mechanisms leading to intraventricular hemorrhage, although its possible role in predicting cerebellar bleeding needs further evaluation.

Placental Pathology, Cerebral Blood Flow, and Intraventricular Hemorrhage in Preterm Infants: Is There a Link?

BACKGROUND

There is growing evidence to support an association between placental inflammation and neurological sequelae of preterm infants. The goal of this study is to evaluate the relationship between placental pathology, post-natal Doppler cerebral resistive indices (RI's), and intraventricular hemorrhage (IVH) in premature infants.

METHODS

In a retrospective cohort study, preterm infants born between 23 0/7 and 32 6/7 weeks' gestation at Parkland Hospital were examined with placental pathology and serial ultrasound Doppler to evaluate for the primary outcome of IVH and death.

RESULTS

A total of 255 infants were included, and 166 (65%) had at least one significant placental pathology, most commonly chorioamnionitis. Infants with placental pathologies were significantly more likely to have mothers with clinical chorioamnionitis and to have lower gestational ages. There was no observed association between placental pathology and IVH or death. Secondary analysis demonstrated that resistive indices obtained from the first and second head ultrasounds were not different in infants with IVH.

CONCLUSION

In this study, we observed a high rate of placental pathologies but no alterations in cerebral indices on ultrasound, or differences in rates of IVH or death. Additional studies are necessary to delineate the relationship between placental pathology, white matter brain injury, and outcomes.

Association of Chorioamnionitis with Cerebral Palsy at Two Years after Spontaneous Very Preterm Birth: The EPIPAGE-2 Cohort Study

OBJECTIVE

To assess whether chorioamnionitis is associated with cerebral palsy (CP) or death at 2 years' corrected age in infants born before 32 weeks of gestation after spontaneous birth.

STUDY DESIGN

EPIPAGE-2 is a national, prospective, population-based cohort study of children born preterm in France in 2011; recruitment periods varied by gestational age. This analysis includes infants born alive after preterm labor or preterm premature rupture of membranes from 24^0/7 to 31^6/7 weeks of gestation. We compared the outcomes of CP, death at 2 years' corrected age, and "CP or death at age 2" according to the presence of either clinical chorioamnionitis or histologic chorioamnionitis. All percentages were weighted by the duration of the recruitment period.

RESULTS

Among 2252 infants born alive spontaneously before 32 weeks of gestation, 116 (5.2%) were exposed to clinical chorioamnionitis. Among 1470 with placental examination data available, 639 (43.5%) had histologic chorioamnionitis. In total, 346 infants died before 2 years and 1586 (83.2% of the survivors) were evaluated for CP at age 2 years. CP rates were 11.1% with and 5.0% without clinical chorioamnionitis (P = .03) and 6.1% with and 5.3% without histologic chorioamnionitis (P = .49). After adjustment for confounding factors, CP risk rose with clinical chorioamnionitis (aOR 2.13, 95% CI 1.12-4.05) but not histologic chorioamnionitis (aOR 1.21, 95% 0.75-1.93). Neither form was associated with the composite outcome "CP or death at age 2."

CONCLUSIONS

Among infants very preterm born spontaneously, the risk of CP at a corrected age of 2 years was associated with exposure to clinical chorioamnionitis but not histologic chorioamnionitis.

Microbial invasion of the amniotic cavity is associated with impaired cognitive and motor function at school age in preterm children

BACKGROUND

Chorioamnionitis is an important cause of preterm delivery. Data on neurodevelopmental outcome in exposed infants are inconsistent due to difficulties in diagnosing intrauterine infection/inflammation and lack of detailed long-term follow-up. We investigate cognitive and motor function in preterm infants at early school age and relate the findings to bacteria in amniotic fluid obtained by amniocentesis (microbial invasion of the amniotic cavity (MIAC)) or placenta findings of histological chorioamnionitis (HCA) or fetal inflammatory response syndrome (FIRS).

METHOD

Sixty-six infants with gestational age <34 weeks at birth and without major disabilities were assessed using WISC-III and the Bruininks-Oseretsky Test of Motor Proficiency. Results were corrected for gestational age and sex.

RESULTS

Children exposed to MIAC had significantly lower scores for full-scale IQ and verbal IQ compared to the non-MIAC group and the difference in full-scale IQ remained after correction for confounding factors. The MIAC group had also significantly lower motor scores after correction. In contrast, motor function was not affected in infants exposed to HCA or FIRS and differences between groups for cognitive scores were lost after corrections.

CONCLUSION

Exposure to bacteria in amniotic fluid is associated with lower motor and cognitive scores in school age preterm infants without major disabilities.

Histologic chorioamnionitis concomitant placental abruption and its effects on pregnancy outcome

INTRODUCTION

Two possible causative pathways have been suggested to participate in the development of placental abruption (PA), an acute inflammatory pathway and placental vascular derived, a chronic pathway. We aimed to study the impact of the inflammatory pathway on maternal and neonatal outcome.

METHODS

The computerized medical files and placental reports of all pregnancies diagnosed with PA, between 11/2008-1/2019, at 24-42 weeks, were reviewed. Placental lesions were classified according to "Amsterdam" criteria into maternal and fetal vascular malperfusion lesions, acute inflammatory responses and chronic villitis. Composite neonatal morbidity included ≥1 of the following: seizures, intra-ventricular hemorrhage (IVH), hypoxic-ischemic encephalopathy, periventricular leukomalacia (PVL), blood transfusion, necrotizing enterocolitis (NEC), neonatal sepsis, respiratory distress syndrome, or neonatal death. Maternal and neonatal outcome were compared between PA with and without histologic chorioamnionitis (HC).

RESULTS

As compared to the PA without HC group (n = 267), the PA with HC group (n = 77) was characterized by lower gestational age (GA) at delivery (32.9 ± 5.5 vs. 35.6 ± 4.1 weeks, p < 0.001), higher rates of oligohydramnios (p < 0.001), bloody amniotic fluid at labor (p < 0.001), maternal postpartum fever (p < 0.001), longer maternal hospitalization (<0.001), and increased composite adverse neonatal morbidity (41.6% vs. 22.8%, p = 0.002). By multivariate analysis, GA and HC were found to be independently associated with adverse neonatal outcome, aOR 0.63 95% CI 0.43-0.78, p < 0.001, and aOR1.12, 95% CI 1.02-3.87, p = 0.04, respectively.

DISCUSSION

The involvement of the inflammatory causative pathway in the development of placental abruption, is associated with increased maternal and neonatal morbidity.

Is chorioamnionitis associated with neurodevelopmental outcomes in preterm infants? A systematic review and meta-analysis following PRISMA

BACKGROUND

The relationships between chorioamnionitis (CA) and neurodevelopmental outcomes in preterm infants remain controversial. The meta-analysis aims to evaluate the associations between CA and neurodevelopmental deficits in preterm infants.

METHODS

All studies exploring the associations between CA and neurodevelopmental deficits in preterm infants were retrieved from the following databases: PubMed, Embase, OVID, EBSCO, ProQuest, CDSR, and CENTRAL. The NOS was used to evaluate the quality of the studies, RevMan was adopted to analyze the data.

RESULTS

Twelve studies involving 4267 preterm infants were included. The ORs across studies was 0.95 (P = .77, I = 51%) for cognitive deficits, 1.09 (P = .44, I = 10%) for psychomotor deficits, 1.21 (P = .08, I = 25%) for language deficits, 2.34 (P = .02, I = 0%) for performance intelligence quotient impairment and 2.81 (P = .03, I = 0%) for verbal intelligence quotient impairment. Subgroup analyses based on the severity of cognitive deficits indicated that CA might be correlated with severe cognitive deficits (P = .01, I = 0%) but not with mild cognitive deficits (P = .40, I = 19%). In terms of the CA category, clinical CA may be related to overall psychomotor deficits (P = .01, I = 25%) and overall language deficits (P < .00001, I = 23%) other than histological CA.

CONCLUSION

In preterm infants, CA might be a risk factor for performance and verbal intelligence quotient impairment and severe cognitive deficits, and clinical CA might be a risk factor for overall psychomotor and language deficits.

Histological chorioamnionitis, antenatal steroids, and neonatal outcomes in very low birth weight infants: A nationwide study

Background

The aim of this study was to investigate whether some associations between histological chorioamnionitis (HCA) and favorable neonatal outcomes might be linked to those of antenatal steroids (AS) by determining the separate as well as the combined associations of HCA and AS with neonatal outcomes in very low birth weight infants (VLBWIs).

Methods

This was a population-based study of VLBWIs born at 20–33 weeks’ gestation between January 2013 and December 2015 from the Korean Neonatal Network. A total of 4652 VLBWIs were enrolled for prevalence study. Of these, 2900 singleton VLBWIs were used for outcome analyses to evaluate individual associations of HCA and AS simultaneously with correction for potential perinatal factors and an interaction term of HCA and AS.

Results

The overall prevalence of HCA was 34.9% (1623 VLBWIs). Multivariable logistic regression demonstrated that HCA was associated with decreased mortality (adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.29–0.91; P = 0.022), AS were associated with reduction in mortality (aOR, 0.59; 95% CI, 0.39–0.90; P = 0.014) and neonatal seizure (aOR, 0.57; 95% CI, 0.37–0.86; P = 0.008), and a combination of HCA and AS was associated with remarkably lowered severe intraventricular hemorrhage by interacting with each other (aOR, 0.47; 95% CI, 0.25–0.88; P = 0.019).

Conclusions

We suggest that in VLBWIs HCA and AS may be favorable independent factors for neonatal outcome and may also work in synergy for neuroprotection.

The relationship between histologic chorioamnionitis and decidual macrophage polarization and their influence on outcomes of neonates born before the 32nd gestational week

PURPOSE

To explore the relationship between histologic chorioamnionitis (HCA) and decidual macrophage (DM) polarization and their influence on outcomes of neonates born before the 32nd gestational week.

MATERIALS AND METHODS

Eighty-four neonates and their placentas were included in this retrospective case-control study and divided into two groups: with and without HCA present (HCA + and HCA-). Neonatal, maternal, and placental risk factors were explored and their influence on neonatal outcomes was examined. We used CD68 and iNOS as markers for polarized DMs type 1 (M1) and CD163, CD206 and arginase (Arg-1) for polarized DMs type 2 (M2).

RESULTS

HCA was present in 47 (56%) cases, and 37 (44%) cases were without the present HCA. There was no statistically significant difference in neonatal risk factors between the two groups (HCA + and HCA-). Higher rates of HCA (p = .042) were observed in mothers who received antepartum corticosteroid therapy. The frequency of vaginal deliveries in HCA + pregnancies was significantly higher than in HCA- pregnancies where deliveries by cesarean section were more frequently observed (p < .001). M2 DM were more abundant in the HCA + group (p = .035). Multiple regression model assessed the association between the presence of HCA, M1, and M2 DM with ROP stages. It has been observed that HCA is a risk factor for ROP stages (β coefficient = 0.34, r_partial = 0.246, p = .024). With the logistic regression model, the association between the presence of HCA, M1, and M2 DM with neonatal nCPAP respiratory support and necrotizing enterocolitis (NEC) was assessed. The presence of M2 macrophages in decidua is an independent risk factor for neonatal nCPAP respiratory support (coefficient -0.07, OR = 0.928, 95% CI 0.87-0.99, p = .024) and the presence of M1 macrophages in decidua increases the risk for NEC (coefficient 0.010, OR = 1.0108, 95% CI 1.00-1.02, p = .032).

CONCLUSIONS

The significantly more abundant presence of M2 DM was detected in HCA + placentas and their association with the increased risk for neonatal nCPAP respiratory support was observed. On the contrary, the presence of M1 DM increases the risk for NEC. The presence of HCA is a risk factor for ROP stages.

Gut and immune effects of bioactive milk factors in preterm pigs exposed to prenatal inflammation

Prenatal inflammation may predispose to preterm birth and postnatal inflammatory disorders such as necrotizing enterocolitis (NEC). Bioactive milk ingredients may help to support gut maturation in such neonates, but mother's milk is often insufficient after preterm birth. We hypothesized that supplementation with bioactive ingredients from bovine milk [osteopontin (OPN), caseinoglycomacropeptide (CGMP), colostrum (COL)] supports gut, immunity, and NEC resistance in neonates born preterm after gram-negative infection before birth. Using preterm pigs as a model for preterm infants, fetal pigs were given intraamniotic injections of lipopolysaccharide (LPS; 1 mg/fetus) and delivered 3 days later (90% gestation). For 5 days, groups of LPS-exposed pigs were fed formula (FOR), bovine colostrum (COL), or formula enriched with OPN or CGMP. LPS induced intraamniotic inflammation and postnatal systemic inflammation but limited effects on postnatal gut parameters and NEC. Relative to FOR, COL feeding to LPS-exposed pigs showed less diarrhea, NEC severity, reduced gut IL-1β and IL-8 levels, greater gut goblet cell density and digestive enzyme activities, and blood helper T-cell fraction. CGMP improved neonatal arousal and gut lactase activities and reduced LPS-induced IL-8 secretion in intestinal epithelial cells (IECs) in vitro. Finally, OPN tended to reduce diarrhea and stimulated IEC proliferation in vitro. No effects on villus morphology, circulating cytokines, or colonic microbiota were observed among groups. In conclusion, bioactive milk ingredients exerted only modest effects on gut and systemic immune parameters in preterm pigs exposed to prenatal inflammation. Short-term, prenatal exposure to inflammation may render the gut less sensitive to immune-modulatory milk effects. NEW & NOTEWORTHY Prenatal inflammation is a risk factor for preterm birth and postnatal complications including infections. However, from clinical studies, it is difficult to separate the effects of only prenatal inflammation from preterm birth. Using cesarean-delivered preterm pigs with prenatal inflammation, we documented some beneficial gut effects of bioactive milk diets relative to formula, but prenatal inflammation appeared to decrease the sensitivity of enteral feeding. Special treatments and diets may be required for this neonatal population.

Prenatal Risk Factors for Adverse Developmental Outcome in Preterm Infants-Systematic Review

Background: Preterm infants are still at an increased risk for suboptimal neurodevelopmental outcomes when compared with term born infants. The development of a child born preterm can be jeopardized by suboptimal conditions during pregnancy, in addition to the suboptimal growth environment postnatally compared to the normal in utero environment. This review summarizes the literature on the role of chorioamnionitis, placental insufficiency, and maternal smoking on the developmental outcomes of preterm infants. Methods: A systematic database search was performed to identify all original articles published on or before September 12, 2018 that evaluated the impact of clinical or histological chorioamnionitis, abnormal prenatal fetal and placental blood flow, and prenatal smoking exposure on the neuropsychological and cognitive outcomes of preterm infants. We identified a total of 54 studies. Thirty five original articles evaluated the effects of clinical or histological chorioamnionitis; 15 studies evaluated the effects of abnormal blood flow patterns; and four studies evaluated the effects of maternal smoking during pregnancy. Results: The studies on prenatal risk factors showed conflicting results about the impact on the neurodevelopment of preterm infants. The majority of the studies did not show that chorioamnionitis poses a direct risk to the development of preterm infants. The role of abnormal prenatal placental and fetal blood flow on the development of preterm infants remained inconclusive because the sample sizes were often small and methodological problems complicated the interpretation of the data. Maternal smoking during pregnancy was assessed only in one cohort which showed that maternal smoking is a risk for suboptimal cognitive and neuropsychological development in preterm infants. Conclusions: This review summarizes the data on several prenatal risk factors which play a role in the developmental outcomes of preterm infants. To optimize the developmental outcomes, we need to first optimize the fetal wellbeing before birth. More research that extends from the fetal life to long-term developmental outcomes is needed.

Impact of different stages of intrauterine inflammation on outcome of preterm neonates: Gestational age-dependent and -independent effect

Objective

To investigate the impact of different stages of intrauterine inflammation (IUI) on neonatal outcomes, before and after adjusting for gestational age (GA) and other perinatal confounders.

Methods

This was an observational, prospective, single-center cohort study including all eligible neonates with GA < 35 weeks and/or birth weight ≤ 1500 g born at a 3^rd level Neonatal Intensive Care Unit between 2011 and 2014. Pathological patterns of placenta, membranes and cord were classified according to Redline’s criteria. Multivariable linear and logistic regression models were applied, either including or not GA among the covariates.

Results

Of the 807 enrolled neonates, 134 (16.6%) had signs of IUI: among these, 54.5% showed just histological chorioamnionitis (HCA), 25.4% had HCA + funisitis (FUN) stage 1, and 20.1% had HCA + FUN stage 2–3. At univariate analysis, HCA increased the risk for retinopathy of prematurity (ROP) and bronchopulmonary dysplasia, while FUN (any stage) had a deleterious impact on all outcomes investigated. After adjustment for covariates not including GA, HCA was a risk factor only for ROP (OR = 2.8, CI: 1–7.8), while FUN (any stage) was still associated with increased ORs for all outcomes (p <0.01). Upon inclusion of GA in the regression model, the results differed remarkably. HCA was associated with lower risk for mechanical ventilation (OR = 0.3, CI: 0.1–0.7) and need for surfactant (OR = 0.5, CI: 0.2–0.9), while FUN (any stage) worsened clinical conditions at birth (p <0.05), increased the risk for early-onset sepsis (p <0.01), and increased the length of mechanical ventilation (FUN stage 2–3 only, RC = 6.5 days, CI: 2–11). No other outcome was affected.

Conclusions

IUI, especially FUN, negatively impact most neonatal morbidities, but its effect is partially reverted adjusting for GA. Considered that GA is an intermediate variable interposed between prenatal causes of prematurity and outcomes, the appropriateness of adjusting for GA may be questionable.

Histological chorioamnionitis and developmental outcomes in very preterm infants

OBJECTIVE

To characterize the association of histological chorioamnionitis (HCA) with neurodevelopmental outcomes in children born at <30 weeks gestation.

STUDY DESIGN

This retrospective cohort study included infants born 2006-2012 in whom placental histopathology, neonatal outcomes, and Bayley-III assessment at age 2 years were available. We assessed the association of HCA exposure with cognitive, language, and motor delay with logistic regression models adjusted for gestational age, sex, small for gestational age and brain injury.

RESULTS

Of 1353 infants, 985 had histological and neonatal data available, and 708 infants had Bayley-III assessments. HCA-exposed infants were at higher risk of some neonatal adverse outcomes, and stage of HCA correlated with low Apgar score and early-onset sepsis. Exposure to HCA was not associated with neurodevelopmental outcomes in adjusted models including stage of HCA.

CONCLUSIONS

Exposure to HCA, especially higher stage, was associated with neonatal morbidity but not with adverse neurodevelopmental outcomes at 2 years of age.

Association of Histologic Chorioamnionitis With Perinatal Brain Injury and Early Childhood Neurodevelopmental Outcomes Among Preterm Neonates

IMPORTANCE

Understanding the role of chorioamnionitis, a major factor leading to preterm birth, in the pathogenesis of neonatal brain injury and adverse neurodevelopmental outcomes may help in identifying potentially modifiable perinatal variables affecting brain health and outcomes among children born preterm.

OBJECTIVE

To evaluate whether histologic chorioamnionitis among neonates born very preterm is associated with intraventricular hemorrhage (IVH) and punctate white matter injury (WMI) or with adverse neurodevelopmental outcomes during early childhood.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study conducted across 3 academic centers (from April 2006 to September 2013 in Canada, from March 2007 to March 2013 in the Netherlands, and from January 2004 to August 2011 in the United States). Children who were born preterm (24-32 weeks' gestation) and who had undergone a placental pathologic evaluation, magnetic resonance imaging as soon as clinically stable, and Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) assessments between 18 and 24 months' corrected age (CA) were included. Magnetic resonance imaging scans were assessed for grade of IVH and volume of punctate WMI. Data analysis occurred between December 2016 and January 2018. Final multivariable analyses examining the association of chorioamnionitis with motor and cognitive outcomes accounted for academic center and perinatal and postnatal factors.

MAIN OUTCOMES AND MEASURES

Punctate WMI volume and IVH detected on neonatal magnetic resonance imaging scans; motor and cognitive outcomes defined using Bayley-III assessments conducted among these children between 18 and 24 months' CA.

RESULTS

Of 350 neonates (182 male) in the final cohort, 145 (41.4%) had histologic chorioamnionitis. Gestational age was significantly lower among those with chorioamnionitis (median, 26.4 weeks; interquartile range [IQR], 25.6-27.7 weeks) than among those without chorioamnionitis (median, 28.0 weeks; IQR, 27.0-29.7 weeks). Chorioamnionitis was not associated with IVH or WMI, nor was it associated with worse motor outcomes in univariable or multivariable analyses (adjusted Bayley-III motor score, -2.2; 95% CI, -5.6 to 1.3). Cognitive scores were marginally yet statistically significantly lower among children with chorioamnionitis (median, 105; IQR, 95-110) than among those without chorioamnionitis (median, 105; IQR, 100-115) in the univariable model. This difference was attenuated in the multivariable model (adjusted Bayley-III cognitive score, -3.0; 95% CI, -6.4 to 0.4).

CONCLUSIONS AND RELEVANCE

Histologic chorioamnionitis was not associated with IVH or WMI near birth or with worse cognitive or motor outcomes from 18 to 24 months' CA after accounting for perinatal factors. Postnatal factors attenuated the association between chorioamnionitis and neurodevelopmental outcomes, highlighting the importance of preventing postnatal illness, such as infection, to promote optimal outcomes among children born preterm.

Preterm infant outcomes in relation to the gestational age of onset and duration of prelabour rupture of membranes: a retrospective cohort study

OBJECTIVE

To determine the hospital outcomes of liveborn infants at 23-31 weeks following prelabour preterm rupture of membranes (PPROM).

METHOD

A regional retrospective cohort study of 4454 infants of 23-31 weeks' gestation admitted to a tertiary neonatal network between 2007 and 2011. Primary outcome was the composite chronic lung disease (CLD) or mortality at discharge.

RESULTS

225 (5%) neonates had a history of PPROM occurring prior to 24⁺⁰ weeks (Early-PPROM), 829 (19%) had a history of PPROM at or after 24⁺⁰ weeks' gestation (Late-PPROM) and 3400 (76%) had no history of PPROM (No-PPROM). In comparison to No-PPROM, Early-PPROM group had higher CLD/mortality in infants born at 23-27 weeks (OR 1.95; 95% CI 1.34 to 2.85) and 28-31 weeks (OR 4.98; 95% CI 2.99 to 8.28). Within Early-PPROM group, the latency of PPROM >14 days had lower CLD/mortality in comparison to latency ≤14 days (57.6% vs 77%, OR 0.40; 95% CI 0.21 to 0.76). Late-PPROM group had significantly lower CLD/mortality in comparison to No-PPROM group at 23-27 weeks (OR 0.50; 95% CI 0.37 to 0.69) and 28-31 weeks (OR 0.50; 95% CI 0.36 to 0.71). Within Late-PPROM group, latency >14 days was associated with an increased CLD/mortality in 28-31 weeks (14.1% vs 5.4%, OR 2.88; 95% CI 1.31 to 6.38).

CONCLUSIONS

Early-PPROM prior to 24 weeks' gestation had high incidence of CLD/mortality even after correcting for gestational age. Late-PPROM at or after 24 weeks had lower CLD/mortality compared with No-PPROM. Latency >14 days in Late-PPROM group at 28-31 week group increased the odds of CLD/mortality.

The role of systemic inflammation linking maternal BMI to neurodevelopment in children

Children of obese mothers are at increased risk of developmental adversities. Maternal obesity is linked to an inflammatory in utero environment, which, in turn, is associated with neurodevelopmental impairments in the offspring. This is an integrated mechanism review of animal and human literature related to the hypothesis that maternal obesity causes maternal and fetal inflammation, and that this inflammation adversely affects the neurodevelopment of children. We propose integrative models in which several aspects of inflammation are considered along the causative pathway linking maternal obesity with neurodevelopmental limitations.

Chorioamnionitis and Five-Year Neurodevelopmental Outcome in Preterm Infants

BACKGROUND

Chorioamnionitis, a risk factor for preterm delivery, has been suggested to be associated with suboptimal neurological development in premature infants.

OBJECTIVE

To evaluate the association between chorioamnionitis and neurodevelopment in preterm infants at 5 years of age. Methods Very low birth weight and very low gestational age infants (n = 197) were recruited. Placental samples (n = 117) were evaluated for histological chorioamnionitis. Fetal histological chorioamnionitis was analyzed as a subgroup. The diagnosis of clinical chorioamnionitis was derived from medical records. Neurodevelopmental impairments were evaluated at 2 years of age, and cognitive development (n = 188) and neuropsychological performance (n = 193) were evaluated at 5 years of age.

RESULTS

There were no associations between histological or clinical chorioamnionitis and neurodevelopmental impairments at 2 years of age. Clinical chorioamnionitis and fetal histological chorioamnionitis were not associated with cognitive development or neuropsychological performance, but histological chorioamnionitis was associated with poorer cognitive outcome (regression coefficient = -7.22, 95% CI: -14.31 to -0.13) and weaker memory and learning functions (regression coefficient = -1.29, 95% CI: -2.40 to -0.18) at 5 years of age.

CONCLUSION

Our study findings do not support clinical chorioamnionitis having a major independent role in the pathogenesis of neurodevelopmental problems in very preterm infants. Histological chorioamnionitis was associated with slightly less optimal performance at 5 years of age, but further studies are needed to verify the clinical significance of these findings.

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.

The effect of histological chorioamnionitis on the short-term outcome of preterm infants ≤32 weeks: a single-center study

BACKGROUND AND OBJECTIVES

Chorioamnionitis (CA) is an acute inflammation of the membranes and chorion of the placenta. The aim of this study was to determine the effect of histological CA on the short-term outcome of preterm infants.

SUBJECTS AND METHODS

The clinical characteristics and outcomes of the preterm infant including respiratory distress syndrome, duration of mechanical ventilation, patent ductus arteriosus (PDA) requiring medical treatment or ligation, necrotizing enterocolitis, bronchopulmonary dysplasia, death and intraventricular hemorrhage (IVH; grade III-IV) were analyzed.

RESULTS

Two hundred and eighty-one infants born at ≤32 weeks gestational ages were included. Infants were divided into two groups: one with histological CA (n = 145) and without histological CA (n = 136). Mean gestational age was 28.8 ± 2.6 weeks and 29.1 ± 2.5 weeks, and mean birth weight was 1138 ± 350 g and 1210 ± 299 g, respectively. There were no differences in gestational age and birth weight among the groups. Compared with the group, histological CA was associated with early onset sepsis (p = 0.007), PDA (p = 0.003), IVH (p = 0.03), and death (p = 0.04).

CONCLUSION

Maternal histological CA is an important risk factor for preterm deliveries and associated with serious morbidities such as early onset sepsis, IVH, PDA and increased mortality.

Perinatal and early postnatal factors underlying developmental delay and disabilities

A delay in meeting developmental milestones may be secondary to perinatal events, involving complicated interactions between mother and fetus during delivery. Maternal factors including weight, diet, and morbidities can affect neonatal adaptation and later development. Prematurity, low birth weight, and previous intrauterine insults as well as complications during delivery of a previously normal fetus increase the risk for perinatal stress. In this article, the literature on perinatal and early postnatal factors that underlie risks for developmental delay and disabilities is reviewed. Studies that concern neuroprotective therapies and prediction of long-term neurologic outcome by clinical examination, neuroimaging techniques, and electroencephalographic studies are reviewed as well.

Innate immune regulation by toll-like receptors in the brain

The innate immune system plays an important role in cerebral health and disease. In recent years the role of innate immune regulation by toll-like receptors in the brain has been highlighted. In this paper the expression of toll-like receptors and endogenous toll-like receptor ligands in the brain and their role in cerebral ischemia will be discussed. Further, the ability of systemic toll-like receptor ligands to induce cerebral inflammation will be reviewed. Finally, the capacity of toll-like receptors to both increase (sensitization) and decrease (preconditioning/tolerance) the vulnerability of the brain to damage will be disclosed. Studies investigating the role of toll-like receptors in the developing brain will be emphasized.

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.