Antenatal steroids may reduce adverse neurological outcome following chorioamnionitis: neurodevelopmental outcome and chorioamnionitis in premature infants

The histologic fetal inflammatory response and neonatal outcomes: systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the prognostic role of concomitant histological fetal inflammatory response with chorioamnionitis on neonatal outcomes through a systematic review and meta-analysis of existing literature.

DATA SOURCES

The primary search was conducted on October 17, 2021, and it was updated on May 26, 2023, across 4 separate databases (MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and Scopus) without using any filters.

STUDY ELIGIBILITY CRITERIA

Observational studies reporting obstetrical and neonatal outcomes of infant-mother dyads with histological chorioamnionitis and histological fetal inflammatory response vs infant-mother dyads with histological chorioamnionitis alone were eligible. Studies that enrolled only preterm neonates, studies on neonates born before 37 weeks of gestation, or studies on neonates with very low birthweight (birthweight <1500 g) were included. The protocol was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42021283448).

METHODS

The records were selected by title, abstract, and full text, and disagreements were resolved by consensus. Random-effect model-based pooled odds ratios with corresponding 95% confidence intervals were calculated for dichotomous outcomes.

RESULTS

Overall, 50 studies were identified. A quantitative analysis of 14 outcomes was performed. Subgroup analysis using the mean gestational age of the studies was performed, and a cutoff of 28 weeks of gestation was implemented. Among neonates with lower gestational ages, early-onset sepsis (pooled odds ratio, 2.23; 95% confidence interval, 1.76-2.84) and bronchopulmonary dysplasia (pooled odds ratio, 1.30; 95% confidence interval, 1.02-1.66) were associated with histological fetal inflammatory response. Our analysis showed that preterm neonates with a concomitant histological fetal inflammatory response are more likely to develop intraventricular hemorrhage (pooled odds ratio, 1.54; 95% confidence interval, 1.18-2.02) and retinopathy of prematurity (pooled odds ratio, 1.37; 95% confidence interval, 1.03-1.82). The odds of clinical chorioamnionitis were almost 3-fold higher among infant-mother dyads with histological fetal inflammatory response than among infant-mother dyads with histological chorioamnionitis alone (pooled odds ratio, 2.99; 95% confidence interval, 1.96-4.55).

CONCLUSION

This study investigated multiple neonatal outcomes and found association in the case of 4 major morbidities: early-onset sepsis, bronchopulmonary dysplasia, intraventricular hemorrhage, and retinopathy of prematurity.

The aetiology of preterm birth and risks of cerebral palsy and cognitive impairment: A systematic review and meta-analysis

AIM

The associations between the aetiology of preterm birth and later neurodevelopmental outcomes are unclear. A systematic review and meta-analysis examined the existing evidence.

METHODS

The PubMed and Embase databases were searched for papers published in English from inception to 16 December 2020. We included original papers on the causes of preterm birth and the risks of cerebral palsy (CP) and suboptimal cognitive development. Two reviewers independently evaluated the studies and extracted the data.

RESULTS

The literature search yielded 5472 papers and 13 were selected. The aetiology of preterm birth was classified under spontaneous or medically indicated delivery. A meta-analysis was performed, comprising 104 902 preterm infants from 11 papers on CP. Preterm infants born after a medically indicated delivery had a lower CP risk than infants born after spontaneous delivery, with a pooled odds ratio of 0.59 (95% confidence interval 0.40-0.86). This result was robust in the subgroup and sensitivity analyses. Cognitive development was reported in three papers, which suggested that worse outcomes were associated with medically indicated deliveries.

CONCLUSION

The aetiology of preterm delivery may contribute to the risk of CP and cognitive delay. Further research is needed, using individual-level meta-analyses to adjust for possible confounders, notably gestational age.

Association of Funisitis with Short-Term Outcomes of Prematurity: A Frequentist and Bayesian Meta-Analysis

The fetal systemic inflammatory response associated with intra-amniotic inflammation may play a key role in the pathogenesis of complications of preterm birth. Funisitis is the histologic equivalent of the fetal inflammatory response, whereas chorioamnionitis represents a maternal inflammatory response. We conducted a frequentist and Bayesian model average (BMA) meta-analysis of studies investigating the effects of funisitis on short-term outcomes of prematurity. Thirty-three studies (12,237 infants with gestational age ≤ 34 weeks) were included. Frequentist meta-analysis showed that funisitis was associated with an increased risk of any bronchopulmonary dysplasia (BPD), moderate/severe BPD, retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), any sepsis, early-onset sepsis (EOS), and mortality. However, Bayesian meta-analysis showed that the evidence in favor of the alternative hypothesis (i.e., funisitis is associated with an increased risk of developing the outcome) was strong for any IVH, moderate for severe IVH and EOS, and weak for the other outcomes. When the control group was restricted to infants having chorioamnionitis without funisitis, the only outcome associated with funisitis was any IVH. In conclusion, our data suggest that the presence of funisitis does not add an additional risk to preterm birth when compared to chorioamnionitis in the absence of fetal inflammatory response.

Antenatal corticosteroid therapy is associated with a lower risk of cystic periventricular leukomalacia

AIM

To evaluate the association of antenatal corticosteroids (ACS) therapy on the risk for cystic periventricular leukomalacia (c-PVL) in very low birth weight (VLBW), very preterm infants, whilst accounting for the occurrence of major neonatal morbidities; sepsis, necrotising enterocolitis, intraventricular haemorrhage and bronchopulmonary dysplasia.

METHODS

Population-based observational cohort study applying data collected by the Israel national VLBW infant database from 1995-2016.

RESULTS

Cystic PVL was diagnosed in 692 (6.8%) of the 10,170 study infants. Among 7522 infants exposed to ACS, the rate of c-PVL was 5.4%, compared to 10.7% among those not exposed (p < 0.0001). ACS was associated with significantly lower odds for c-PVL (Odds Ratio [OR] 0.69, 95% confidence interval [CI] 0.57-0.84). In subgroup analyses, excluding infants with one or more morbidities the rates of c-PVL ranged from 2.7% to 5.4% among infants exposed to ACS compared to 5.6% to 10.7% in those not exposed (all p < 0.0001). ACS was associated with significantly lower OR's for c-PVL in all subgroups, ranging from 0.52 (95% CI 0.40-0.66) to 0.62 (95% CI 0.50-0.77).

CONCLUSION

Infants exposed to ACS had a significantly lower risk of c-PVL. Subgroup analyses excluding infants with major neonatal comorbidities showed a consistent reduction of 40%-50% in the risk for c-PVL following ACS therapy.

Management of clinical chorioamnionitis: an evidence-based approach

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

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.

The fetal inflammation response syndrome and adverse neonatal outcomes: a meta-analysis

Background: The clinical performance of fetal inflammatory response syndrome (FIRS) is often atypical. The aim of this meta-analysis is to investigate whether FIRS is associated with adverse neonatal outcomes.Methods: PubMed, Embase, and Cochrane Library were used in this study. The adverse neonatal outcomes data including neonatal early-onset sepsis (EOS), bronchopulmonary dysplasia (BPD), periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH), respiratory distress syndrome (RDS), and neonatal death were collected to make analysis.Results: A total of 10 articles (1116 patients) were included in this study. Compared to the non-FIRS group, the FIRS group was associated with higher incidence of adverse neonatal outcomes, such as EOS (RR = 3.10, 95% CI: 1.26, 7.65; p=.014), BPD (RR = 5.93, 95% CI = 4.35, 8,08; p < .001), IVH (RR = 4.89, 95% CI = 2.96, 8.08; p < .001), PVL (RR = 3.32, 95% CI: 1.73, 6.40; p < .001), RDS (2.35, 95% CI = 1.67, 3.31; p < .001), and the neonatal death (RR = 7.04, 95% CI: 3.34, 14.85; p < .001).Conclusions: The FIRS is associated with higher incidence of adverse neonatal outcomes, and is a risk factor of severe neonatal morbidity or death.

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.

Chorioamnionitis in the Development of Cerebral Palsy: A Meta-analysis and Systematic Review

CONTEXT

Chorioamnionitis (CA) has often been linked etiologically to cerebral palsy (CP).

OBJECTIVES

To differentiate association from risk of CA in the development of CP.

DATA SOURCES

PubMed, Cochrane Library, Embase, and bibliographies of original studies were searched by using the keywords (chorioamnionitis) AND ((cerebral palsy) OR brain).

STUDY SELECTION

Included studies had to have: (1) controls, (2) criteria for diagnoses, and (3) neurologic follow-up. Studies were categorized based on: (1) finding incidence of CP in a CA population, or risk of CP; and (2) incidence of CA in CP or association with CP.

DATA EXTRACTION

Two reviewers independently verified study inclusion and extracted data.

RESULTS

Seventeen studies (125 256 CA patients and 5 994 722 controls) reported CP in CA. There was significantly increased CP inpreterm histologic chorioamnionitis (HCA; risk ratio [RR] = 1.34, P < .01), but not in clinical CA (CCA). Twenty-two studies (2513 CP patients and 8135 controls) reported CA in CP. There was increased CCA (RR = 1.43, P < .01), but no increase in HCA in preterm CP. Increased HCA was found (RR = 4.26, P < .05), as well as CCA in term/near-term CP (RR = 3.06, P < .01).

CONCLUSIONS

The evidence for a causal or associative role of CA in CP is weak. Preterm HCA may be a risk factor for CP, whereas CCA is not. An association with term and preterm CP was found for CCA, but only with term CP for HCA.

Infections and Brain Development

Several different bodies of evidence support a link between infection and altered brain development. Maternal infections, such as influenza and human immunodeficiency virus, have been linked to the development of autism spectrum disorders, differences in cognitive test scores, and bipolar disorder; an association that has been shown in both epidemiologic and retrospective studies. Several viral, bacterial, and parasitic illnesses are associated with alterations in fetal brain structural anomalies including brain calcifications and hydrocephalus. The process of infection can activate inflammatory pathways causing the release of various proinflammatory biomarkers and histological changes consistent with an infectious intrauterine environment (chorioamnionitis) or umbilical cord (funisitis). Elevations in inflammatory cytokines are correlated with cerebral palsy, schizophrenias, and autism. Animal studies indicate that the balance of proinflammatory and anti-inflammatory cytokines is critical to the effect prenatal inflammation plays in neurodevelopment. Finally, chorioamnionitis is associated with cerebral palsy and other abnormal neurodevelopmental outcomes. In conclusion, a plethora of evidence supports, albeit with various degrees of certainty, the theory that maternal infection and inflammation that occur during critical periods of fetal development could theoretically alter brain structure and function in a time-sensitive manner.

Antenatal Corticosteroids for Reducing Adverse Maternal and Child Outcomes in Special Populations of Women at Risk of Imminent Preterm Birth: A Systematic Review and Meta-Analysis

BACKGROUND

This study synthesizes available evidence on antenatal corticosteroids (ACS) use among special subgroups of women at risk of imminent preterm birth, including those (1) with pregestational and gestational diabetes mellitus, (2) undergoing elective caesarean section (CS) in late preterm (34 to<37 weeks), (3) with chorioamnionitis, and (4) with growth-restricted fetuses.

METHODS

A systematic search of MEDLINE, EMBASE, CINAHL, Cochrane Library, POPLINE, and World Health Organization Regional Databases was conducted for all comparative studies. Two reviewers independently determined study eligibility, extracted data, and assessed study quality. Pooled mean differences and odds ratios with 95% confidence intervals were estimated from available data, based on fixed- and random-effects models, as appropriate.

RESULTS

No eligible studies were identified for ACS use in diabetic pregnant women or those undergoing elective CS at late preterm. Nine studies each on ACS use in women with chorioamnionitis and in women with fetal growth restriction met inclusion criteria; eight studies were separately included in the meta-analyses for the two subpopulations. For ACS administration in women with chorioamnionitis, pooled analyses showed reductions in neonatal mortality (OR: 0.49, 95% CI: 0.34-0.73), respiratory distress syndrome (OR: 0.58, 95% CI: 0.44-0.76), intraventricular haemorrhage (OR: 0.41, 95% CI: 0.24-0.69), and severe intraventricular haemorrhage (OR: 0.40, 95% CI: 0.24-0.69). Maternal and long-term newborn outcomes were not reported. Effects of ACS use were inconclusive for cases with fetal growth restriction.

CONCLUSION

Direct evidence on the effectiveness and safety of ACS is lacking for diabetic pregnant women at risk of preterm birth and those undergoing elective late-preterm CS, though this does not necessarily recommend against their use in diabetic women. While evidence remains inconclusive for women with growth-restricted preterm neonates, ACS appears to benefit preterm neonates delivered by women with chorioamnionitis. High-quality studies on maternal and long-term child outcomes in more diverse settings are needed to establish the balance of potential harms versus benefits in using ACS for these understudied subgroups.

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.

Long-term outcomes of antenatal corticosteroids treatment in very preterm infants after chorioamnionitis

PURPOSE

To evaluate the effect of antenatal corticosteroids (AC) therapy on short- and long-term outcomes among very low birth weight preterm infants after histologic chorioamnionitis (HCA).

METHODS

We performed a retrospective analysis of 5240 single very low birth weight (VLBW) infants born at 22 + 0 and 33 + 6 weeks of gestation between 2003 and 2007, who registered to the Neonatal Research Network Japan. The effects of AC therapy on mortality, neurodevelopmental outcomes at 3 years of age and neonatal morbidities were analyzed in the groups with or without HCA using logistic regression analysis.

RESULTS

In the study subjects, 840 were with HCA, 2734 were without HCA, and 1666 were excluded without data for HCA. AC therapy was significantly associated with decreasing mortality before 3 years of age; [0.52 (0.32-0.86)], [odds ratio (95 % confidence intervals]. There were no differences between the two groups regarding neurodevelopmental outcomes, including cerebral palsy [0.90 (0.41-1.99)], development quotient <70 [0.93 (0.48-1.81)], visual impairment [0.46 (0.04-5.18)], and severe hearing impairment [4.00 (0.30-53.4)] in the group with HCA as well as without HCA. Regarding neonatal morbidities, AC therapy was associated with a lower incidence of respiratory distress syndrome [0.67 (0.50-0.91)], sepsis [0.62 (0.41-0.94)], late-onset adrenal insufficiency [0.62 (0.39-0.98)] and an increased incidence of chronic lung disease [1.62 (1.18-2.24)] in the group with HCA. In the group without HCA, AC therapy was associated with decreasing respiratory distress syndrome [0.60 (0.43-0.84)] and increasing chronic lung disease [1.34 (1.11-1.62)].

CONCLUSION

AC therapy is significantly associated with reduced mortality before 3 years of age in VLBW infants with HCA, but not with neurodevelopmental outcomes, which was same as the results found in infants without HCA. AC therapy is recommended for women with suspected chorioamnionitis, as well as those without chorioamnionitis.

Impact of chorioamnionitis on short- and long-term outcomes in very low birth weight preterm infants: the Neonatal Research Network Japan

OBJECTIVE

To evaluate the short- and long-term outcomes among very low birth weight (VLBW) preterm infants after histologic chorioamnionitis (HCA).

METHODS

We performed a retrospective analysis of 5849 single infants (birth weight <1500 g) born at a gestational age between 22 + 0 and 33 + 6 weeks. Clinical data were obtained from the Neonatal Research Network Japan between 2003 and 2007. Multivariable logistic regression analyses were performed to assess the effect of HCA on short- and long-term outcome.

RESULTS

According to logistic regression analysis, HCA was associated with lower incidence of respiratory distress syndrome (odds ratio [OR] = 0.54; p < 0.001), increased chronic lung disease (OR = 1.68; p < 0.001) and sepsis (OR = 1.71; p < 0.001) and as a short-term outcomes. There was no significant association with intraventricular hemorrhage (OR = 1.11; p = 0.33), periventricular leukomalacia (OR = 1.07; p = .070) and death before discharge (OR = 0.97; p = 0.084). HCA was associated with increased home oxygen therapy (OR = 3.09; p < 0.001), but not with cerebral palsy (CP; OR = 0.91; p = 0.63), develop quotient < 70 (OR = 1.27; p = 0.17), visual impairment (OR = 1.08; p = 0.77), severe hearing impairment (OR = 1.28; p = 0.62) and death (OR = 0.98; p = 0.91) before three years of age.

CONCLUSIONS

In this retrospective population-based study in Japan, HCA was not a risk factor for death, neurodevelopmental impairment and CP in VLBW three-year-old preterm infants.

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.

Antenatal steroid exposure and outcomes of very premature infants: a regional cohort study

OBJECTIVE

To compare mortality, short-term morbidity and long-term neurodevelopmental outcomes of <29 week premature infants with antenatal steroid exposure (none, incomplete and complete).

PATIENTS AND METHODS

Multicentre retrospective cohort study, within a geographically defined area in Australia served by a network of 10 neonatal intensive care units (NICUs), of infants <29 weeks gestational age, admitted to NICUs between 1998 and 2004. Outcome measures included hospital survival, perinatal complications and functional disability at 2-3 years follow-up.

RESULTS

2549 neonates were included; 319 (12.5%) received no exposure to steroids. Hospital mortality (OR 0.59, 95% CI 0.45 to 0.76, p<0.001, intraventricular haemorrhage (IVH) (OR 0.58, 95% CI 0.42 to 0.81, p=0.001) and necrotising entercolitis (NEC) (OR 0.62, 95% CI 0.42 to 0.91, p=0.018) was less likely in infants with any steroid exposure. Any steroid exposure was associated with less need for surfactant (OR 0.41, 95% CI 0.30 to 0.57, p<0.001) and mechanical ventilation (OR 0.30, 95% CI 0.17 to 0.52, p<0.001). Subgroup analyses demonstrated differences in outcomes only with complete steroid coverage and not with incomplete coverage. Survival benefit and reduction in the incidence of severe IVH was evident from 24 to 28 weeks. Long-term neurodevelopmental data available for 1473 survivors showed no significant difference in outcomes with steroid exposure after multivariate analysis.

CONCLUSIONS

Exposure to a complete course of antenatal steroids is associated with higher infant survival rates, lower rates of severe IVH and NEC compared to an incomplete course or no exposure. Any exposure to steroids reduces the risk of moderate cerebral palsy, however, long-term neurodevelopmental outcome may not be affected by steroid exposure.

The effects of antenatal corticosteroids therapy on very preterm infants after chorioamnionitis

PURPOSE

To evaluate the effectiveness of antenatal corticosteroids (AC) therapy on outcomes of very low birthweight infants with histologic chorioamnionitis.

METHODS

We performed a retrospective analysis of 10,935 single infants born at a gestational age between 22 + 0 and 33 + 6 weeks and birth weight <1,500 g. Clinical data were obtained from the Neonatal Research Network that included the tertiary neonatal intensive care units throughout Japan between 2003 and 2008.

RESULTS

Data of 7,896 infants were available for the period 2003-2008 and were included in the analysis. According to logistic regression analysis, AC were significantly associated with reduced mortality [odds ratio (OR) = 0.50; p < 0.001], lower incidence of respiratory distress syndrome (OR = 0.72; p < 0.001), neonatal seizure (OR = 0.65; p = 0.003) and intraventricular hemorrhage (OR = 0.68; p = 0.001) in cases after histologic chorioamnionitis compared with the cases had no AC therapy (n = 3,271 vs. 4,625). Antenatal corticosteroids were significantly associated with reduced mortality [odds ratio (OR) = 0.60; p < 0.001] among the cases without histologic chorioamnionitis.

CONCLUSION

In the retrospective population-based study in Japan, AC exposure was significantly associated with a lower rate of death and neurological morbidity in cases with histologic chorioamnionitis. These outcome data in Japan will be important for further improvement of antenatal practice and care.

Effect of dexamethasone administered with magnesium sulfate on inflammation-mediated degradation of the blood-brain barrier using an in vitro model

Patients at risk for preterm delivery are frequently administered both antenatal steroids for fetal maturation and magnesium sulfate for neuroprotection. In this study, we investigate whether steroids coadministered with magnesium sulfate preserve blood-brain barrier integrity in neuroinflammation. Human umbilical vein endothelial cells were grown in astroglial conditioned media in a 2-chamber cell culture apparatus. Treatment with tumor necrosis factor-α (TNF-α) or catalytically active recombinant matrix metalloproteinase 9 (MMP-9) simulated neuroinflammation. Membrane integrity was assessed by zona occludens 1 (ZO-1) immunoreactivity, permeability to fluorescently conjugated dextran, and transendothelial electrical resistance (TEER). The TNF-α and MMP-9 treatment increased the rate of dextran transit, decreased TEER, and decreased ZO-1 immunoreactivity at junctional interfaces. Dexamethasone pretreatment alone or in combination with 0.5 mmol/L magnesium sulfate preserved monolayer integrity after inflammatory insult. Magnesium sulfate alone was not protective. This study supports a possible interaction between steroids and magnesium in neuroprotection.

Histological characteristics of the fetal inflammatory response associated with neurodevelopmental impairment and death in extremely preterm infants

OBJECTIVE

To test the hypothesis that increasing severity of the fetal inflammatory response (FIR) would have a dose-dependent relationship with severe neurodevelopmental impairment or death in extremely preterm infants.

STUDY DESIGN

We report 347 infants of 23-28 weeks gestational age admitted to a tertiary neonatal intensive care unit between 2006 and 2008. The primary outcome was death or neurodevelopmental impairment at the 18- to 22-month follow-up. Exposure status was defined by increasing stage of funisitis (stage 1, phlebitis; stage 2, arteritis with or without phlebitis; stage 3, subacute necrotizing funisitis) and severity of chorionic plate vasculitis (inflammation with or without thrombosis).

RESULTS

A FIR was detected in 110 placentas (32%). The rate of severe neurodevelopmental impairment/death was higher in infants with subacute necrotizing funisitis compared with infants without placental/umbilical cord inflammation (60% vs 35%; P < .05). Among infants with stage 1 or 2 funisitis, the presence of any chorionic vasculitis was associated with a higher rate of severe neurodevelopmental impairment/death (47% vs 23%; P < .05). After adjustment for confounding factors, only subacute necrotizing funisitis (risk ratio, 1.87; 95% CI, 1.04-3.35; P = .04) and chorionic plate vasculitis with thrombosis (risk ratio, 2.21; 95% CI, 1.10-4.46; P = .03) were associated with severe neurodevelopmental impairment/death.

CONCLUSION

Severe FIR, characterized by subacute necrotizing funisitis and severe chorionic plate vasculitis with thrombosis, is associated with severe neurodevelopmental impairment/death in preterm infants.

Histological chorioamnionitis and neurodevelopmental outcome in preterm infants

OBJECTIVE

The objective of this study is to examine the neurodevelopmental outcome at 30 to 42 months corrected age of preterm infants with histological chorioamnionitis (HCA).

STUDY DESIGN

The study design is a retrospective cohort study with a prospective follow-up. All surviving infants with birth gestational age <29 weeks, born between 2000 and 2006, who had a neurodevelopmental assessment at 30 to 42 months corrected age were included. We compared the neurodevelopmental outcomes of infants with or without HCA.

RESULT

Of the 384 infants, 197 (51%) were born to mothers with evidence of HCA. Infants with HCA were of lower gestational age (26 weeks vs 26.6 weeks) and more likely to have intraventricular hemorrhage (27.9% vs 14.4%), periventricular leukomalacia (2.5% vs 0%) and retinopathy of prematurity ≥ stage 3 (31.4% vs 22.4%). On univariate analysis, infants with HCA were more likely to have cerebral palsy (12.6% vs 6.4%, P=0.04). There was no significant difference in the incidence of cognitive delay, deafness, blindness, or total major disabilities between the two groups. After adjusting for perinatal variables, HCA was associated with increased risk of cerebral palsy (odds ratio (OR): 2.45; 95% confidence interval (CI) 1.11 to 5.40), but not for total major disabilities (OR: 1.22; 95% CI: 0.64 to 2.34). There was a trend towards increased risk of cerebral palsy with HCA with funisitis.

CONCLUSION

HCA is associated with increased risk of cerebral palsy at 30 to 42 months corrected age in preterm infants.

Cerebral autoregulation in the first day after preterm birth: no evidence of association with systemic inflammation

INTRODUCTION

Both systemic inflammation and impaired cerebral autoregulation (CA) have been associated with brain injury in preterm infants. We hypothesized that impaired CA represents a hemodynamic link between inflammation and brain injury.

RESULTS

Neither fetal vasculitis nor interleukin-6 (IL-6) affected CA significantly. A high level of IL-6 was associated with hypotension (P = 0.03) irrespective of dopamine therapy. The magnitude of impairment in CA increased with decreasing mean arterial blood pressure (MAP) (P = 0.02). No significant associations were found between these parameters and either intraventricular hemorrhage (IVH) (n = 10) or neonatal mortality (n = 8).

DISCUSSION

In conclusion, postnatal inflammation was weakly associated with arterial hypotension, and hypotension was weakly associated with impaired autoregulation. There was no direct association, however, between autoregulation and antenatal or postnatal signs of inflammation.

METHODS

In our study, 60 infants (mean (±SD) of gestational age (GA) 27 (±1.3) wk) underwent continuous recording of MAP and cerebral oxygenation index (OI) by means of near-infrared spectroscopy (NIRS) for 2.3 ± 0.5 h, starting 18 ± 9 h after birth. Coherence and transfer function gain between MAP and OI represented the presence and degree of impairment of CA, respectively. We considered fetal vasculitis (placenta histology) to be an antenatal marker of inflammation, and used the level of IL-6 in blood, measured at 18 ± 10 h after birth, as a postnatal marker of inflammation. Definition of hypotension was MAP (mm Hg) ≤ GA (wk).

Antenatal corticosteroids promote survival of extremely preterm infants born at 22 to 23 weeks of gestation

OBJECTIVE

To evaluate the effectiveness of antenatal corticosteroid (ACS) to improve neonatal outcomes for infants born at <24 weeks of gestation.

STUDY DESIGN

We performed a retrospective analysis of 11,607 infants born at 22 to 33 weeks of gestation between 2003 and 2007 from the Neonatal Research Network of Japan. We evaluated the gestational age effects of ACS administered to mothers with threatened preterm birth on several factors related to neonatal morbidity and mortality.

RESULTS

By logistic regression analysis, ACS exposure decreased respiratory distress syndrome and severe intraventricular hemorrhage in infants born between 24 and 29 weeks of gestation. Cox regression analysis revealed that ACS exposure was associated with a significant decrease in mortality of preterm infants born at 22 or 23 weeks of gestation (adjusted hazard ratio, 0.72; 95% CI, 0.53 to 0.97; P=.03). This effect was also observed at 24 to 25 and 26 to 27 weeks of gestation and in the overall study population.

CONCLUSIONS

ACS exposure improved survival of extremely preterm infants. ACS treatment should be considered for threatened preterm birth at 22 to 23 weeks of gestation.

Neonatal and neurodevelopmental outcomes of very low birth weight infants with histologic chorioamnionitis

OBJECTIVE

To determine survival and neurodevelopmental outcomes at 18 months corrected age among very low birth weight infants ≤ 32 weeks gestation with histologic chorioamnionitis.

STUDY DESIGN

Observational, regionalized, single-center cohort study with prospective follow-up.

RESULTS

Of the 628 infants meeting the selection criteria, 303 (48%) were born to mothers with evidence of histologic chorioamnonitis. Neonates with histologic chorioamnonitis were of lower gestational age and birth weight. On univariate analysis, they were more likely to have hypotension, bronchopulmonary dysplasia, severe intraventricular hemorrhage, severe retinopathy of prematurity, early-onset sepsis, and death. Infants with histologic chorioamnonitis were more likely to have any neurodevelopmental impairment, specifically, mental delay with a lower mental developmental index. When adjusting for perinatal variables, histologic chorioamnonitis had a protective effect on mortality rates (adjusted OR = 0.44, 95% CI: 0.24-0.8; P = .01; n = 619), had a nonsignificant effect on neurodevelopmental impairment (adjusted odds ratio = 1.33, 95% CI: 0.82-2.17; P = .25; n = 496), and was associated with a 4-point lower mental developmental index at 18-months follow-up (adjusted difference -3.93, 95% CI: -7.52 to -0.33; P = .03; n = 496).

CONCLUSIONS

Although infants with histologic chorioamnonitis were at an increased risk for death and neurodevelopmental impairment, after multivariate analyses, histologic chorioamnonitis was not associated with adverse long-term outcomes. Results suggest fetal protection from treatment-responsive maternal infection and inflammation.

Antenatal steroids and neonatal outcome after chorioamnionitis: a meta-analysis

BACKGROUND

There is debate concerning the safety and efficacy of antenatal steroids in preterm labour with suspected intrauterine infection (chorioamnionitis).

OBJECTIVES

We performed a systematic literature review and meta-analysis aimed at evaluating the efficacy and safety of antenatal steroids in clinical and histological chorioamnionitis.

SEARCH STRATEGY

MEDLINE, EMBASE, BioMed Central and the Cochrane databases were searched using the terms 'chorioamnionitis OR intrauterine infection' and '*steroids OR *corticoids'.

SELECTION CRITERIA

Studies that reported selected neonatal outcome measures in preterm infants with clinical or histological chorio-amnionitis, according to antenatal steroid exposure, were eligible.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction and data analysis were performed by two independent investigators. The meta-analysis techniques used included: Mantel-Haenszel analysis; an assessment of study heterogeneity using the Q statistic; and Egger's regression test and funnel plots, to assess publication bias.

MAIN RESULTS

Seven observational studies were included. In histological chorioamnionitis (five studies), antenatal steroids were associated with reduced mortality (OR = 0.45; 95% CI = 0.30-0.68; P = 0.0001), respiratory distress syndrome (OR = 0.53; 95% CI = 0.40-0.71; P < 0.0001), patent ductus arteriosus (OR = 0.56; 95% CI = 0.37-0.85; P = 0.007), intraventricular haemorrhage (IVH; OR = 0.35; 95% CI = 0.18-0.66; P = 0.001) and severe IVH (OR = 0.39; 95% CI = 0.19-0.82; P = 0.01). In clinical chorioamnionitis (four studies), antenatal steroids were associated with reduced severe IVH (OR = 0.29; 95% CI = 0.10-0.89; P = 0.03) and periventricular leucomalacia (OR = 0.35; 95% CI = 0.14-0.85; P = 0.02).

CONCLUSIONS

Antenatal steroids may be safe and reduce adverse neonatal outcome after preterm birth associated with chorioamnionitis. There is a need for randomised clinical trials to address this issue.

A systematic review of intentional delivery in women with preterm prelabor rupture of membranes

OBJECTIVE

To evaluate the effect of intentional delivery versus expectant management in women with preterm prelabor rupture of membranes (PPROM).

METHODS

We searched electronic databases and trials registries, contacted experts, and checked reference lists of relevant studies. Studies were included if they were randomized controlled trials comparing intentional delivery versus expectant management after PPROM, the gestational age of participants was between 30 and 36 weeks, and the study reported one of several pre-determined outcomes.

RESULTS

Four studies were included in the meta-analysis. No difference was found between intentional delivery and expectant management in neonatal intensive care unit (NICU) length of stay (LOS) (weighted mean difference (WMD) -0.81 day, 95% confidence interval (CI) -1.66, 0.04), respiratory distress syndrome (risk difference (RD) -0.01, 95% CI -0.07, 0.06), and confirmed neonatal sepsis (RD -0.01, 95% CI -0.05, 0.04). One study found a significantly lower incidence of suspected neonatal sepsis among the intentional delivery group (RD -0.31, 95% CI -0.50, -0.12; number needed to treat (NNT) 3, 95% CI 2, 8). Maternal LOS was significantly shorter for the intentional delivery group (WMD -1.39 day, 95% CI -2.03, -0.75). There was a significant difference in the incidence of clinical chorioamnionitis favoring intentional delivery (RD -0.16, 95% CI -0.23, -0.10; NNT 6, 95% CI 5, 11). There was no significant difference in the incidence of other maternal outcomes, including cesarean section (RD 0.05, 95% CI -0.01, 0.11).

CONCLUSIONS

Intentional delivery may be favorable to expectant management for some maternal outcomes (chorioamnionitis and LOS). There is insufficient evidence to suggest that either strategy is beneficial or harmful for the baby. Large multicenter trials with primary neonatal outcomes are required to assess whether intentional delivery is associated with less neonatal morbidity.

A multicenter study on the clinical outcome of chorioamnionitis in preterm infants

OBJECTIVE

The purpose of this study was to examine the effects of clinical maternal chorioamnionitis on morbidity and mortality rates among infants who are at < 33 weeks of gestation, adjusted for patient characteristics that included admission neonatal illness severity (Score for Neonatal Acute Physiology, version II; SNAP-II).

STUDY DESIGN

With multivariate logistic regression analysis, prospectively collected hospital outcomes from the Canadian Neonatal Network of singleton infants with birth gestational age of < 33 weeks and clinical chorioamnionitis were compared retrospectively with nonexposed infants.

RESULTS

Of 3094 infants, 477 infants (15.4%) who were exposed to clinical chorioamnionitis had significantly higher admission SNAP-II scores. Bivariate analysis revealed that the neonatal mortality rate was increased significantly in the chorioamnionitis group (10.6% vs 6.1%). Multivariate regression analysis with adjustment for illness severity indicated that chorioamnionitis was associated with an increased risk of early sepsis (odds ratio, 5.54; 95% confidence interval, 2.87-10.69) and severe intraventricular hemorrhage (odds ratio, 1.62; 95% confidence interval, 1.17-2.24) but not neonatal death.

CONCLUSION

Preterm infants who are exposed to clinical chorioamnionitis have an increased risk of early-onset sepsis and severe intraventricular hemorrhage.

Which factors affect the occurrence of severe cerebral lesions in preterm neonates who are born with intrauterine infection?

OBJECTIVE

The purpose of this study was to evaluate which factors affect the occurrence of neonatal ultrasonographic evidence of severe cerebral lesions in the presence of intrauterine infection.

STUDY DESIGN

From a cohort of 567 singleton neonates who were born between 24.0 and 31.6 weeks of gestation, we identified the 180 infants with histologic and/or clinical evidence of intrauterine infection. We excluded stillbirths and congenital anomalies. Obstetric and neonatal variables were related to evidence of severe neonatal ultrasonographic cerebral lesions with the use of logistic regression analysis.

RESULTS

Severe cerebral lesions were identified in 10% of infants (18/180). After we controlled for variables that were clinically relevant, logistic regression analysis demonstrated that ultrasound evidence of severe neonatal cerebral lesions was associated independently with antenatal administration of corticosteroids (adjusted odds ratio, 0.3; 95% CI, 0.11-0.88; P = .03) and occurrence of placental abruption (adjusted odds ratio, 5.4; 95% CI, 1.4-20.7; P = .02).

CONCLUSION

Antenatal administration of corticosteroids in the presence of intrauterine infection has a protective effect on the risk of ultrasonographic evidence of severe neonatal cerebral lesions.

Astrocyte Responses after Neonatal Ischemia: The Yin and the Yang

Neonatal encephalopathy is a major predictor of neurodevelopmental disability in term infants and occurs in 1 to 6 of every 1000 live term births. Despite improvements in perinatal practice during the past several decades, the incidence of cerebral palsy attributed to neonatal asphyxia remained essentially unchanged, primarily because management strategies were supportive and not targeted toward the processes of ongoing injury. Traditionally, experimental research in vivo focused on neurons, and more recently, oligodendrocytes whereas astrocytes have been more or less neglected. This review aims at dissecting possible protective as well as destructive roles of astrocytes in the immature ischemic brain to stimulate further research into this unexplored aspect of brain pathophysiology. NEUROSCIENTIST 14(4):339ndash;344, 2008. DOI: 10.1177/1073858408316003

Cerebral palsy

Cerebral palsy (CP) is a group of disorders of movement and posture resulting from nonprogressive disturbances of the fetal or neonatal brain. More than 80% of cases of CP in term infants originate in the prenatal period; in premature infants, both prenatal or postnatal causes contribute. The most prevalent pathological lesion seen in CP is periventricular white matter injury (PWMI) resulting from vulnerability of the immature oligodendrocytes (pre-OLs) before 32 wk of gestation. PWMI is responsible for the spastic diplegia form of CP and a spectrum of cognitive and behavioral disorders. Oxidative stress and excitotoxicity resulting from excessive stimulation of ionotropic glutamate receptors on preOLs are the most prominent molecular mechanisms for PWMI. Asphyxia around the time of birth in term infants accounts for less than 15% of CP in developed countries but the incidence is higher in underdeveloped areas. Asphyxia causes a different pattern of brain injury and CP than is seen after preterm injuries. This type of CP is associated with the clinical syndrome of hypoxic-ischemic encephalopathy shortly after the insult, and the cortex, basal ganglia, and brainstem are selectively vulnerable to injury. Experimental models indicate that neurons in the neonatal brain are more likely to die by delayed apoptosis extending over days to weeks than those in the adult brain. Neurons die by glutamate-mediated excitotoxicity involving downstream caspase-dependent and caspase-independent cell death pathways. Recent reports indicate that males and females preferentially utilize different pathways. Clinical trials indicate that mild hypothermia reduces death or disability in term infants following asphyxia and basic research suggests that this approach might be combined with pharmacological strategies in the future.

Maternal corticosteroids to prevent intrauterine exposure to hyperthermia and inflammation: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Intrauterine exposure to hyperthermia at term is associated with adverse neonatal neurologic outcomes. The objective of this study was to determine whether prophylactic maternal corticosteroid treatment prevents fetal exposure to hyperthermia and inflammatory cytokines after epidural analgesia.

STUDY DESIGN

A 2-phase, randomized, institutional review board-approved, double-blind, placebo-controlled trial was performed. Term nulliparous women were enrolled at epidural placement. Patients with a temperature of >99.4 degrees F or with diabetes mellitus were excluded. In phase 1, 25 mg methylprednisolone (low dose) or placebo was administered every 8 hours. In phase 2, the treatment dose was increased to 100 mg every 4 hours (high dose). Our primary outcome was a rate of intrapartum fever of >100.4 degrees F. Secondary outcomes were fetal interleukin-6 levels and the rate of neonatal bacteremia.

RESULTS

One hundred one patients were assigned randomly to placebo; 50 patients were assigned to the low-dose group, and 49 patients were assigned to the high-dose group. Treatment with the high dose resulted in a 90% reduction in maternal fever, compared with placebo and low dose therapy (2.0% vs 21.8% vs. 34.0%, respectively; P < .001). Neonatal sepsis evaluations were reduced significantly in the high-dose group (4.1% vs 17.8% vs 24%, respectively; P = .01), but the rates of asymptomatic bacteremia were increased (9.3% vs 0% vs 2.1%, respectively; P = .005). Median cord blood interleukin-6 levels were reduced with the high-dose steroid treatment, but this result was statistically significant only between the high-dose and placebo groups (24.0 +/- 38.5 vs 32.0 +/- 95.0 pg/mL, respectively; P = .02).

CONCLUSION

Prophylaxis with high-dose corticosteroids significantly reduces fetal exposure to hyperthermia and inflammation. However, maternal high-dose corticosteroids increase the rate of neonatal asymptomatic bacteremia. Stress-dose corticosteroid use in labor should trigger consideration of a screening neonatal blood culture.

Anti-inflammatory therapy in the neonatal intensive care unit: present and future

Inflammation has been linked to numerous adverse outcomes in newborns. This paper reviews several major sources of inflammation, methods to reduce exposure, current anti-inflammatory drug therapy and future research directions. The first major source of inflammation--chorioamnionitis--is often present long before delivery; postnatal interventions may not alter outcomes. Reducing the exposure of preterm infants to postnatal inflammatory stimuli such as mechanical ventilation and sepsis may be more effective than anti-inflammatory drug therapy in improving outcomes. If anti-inflammatory drug therapy is considered necessary, the only drug currently proven to decrease extubation failure and bronchopulmonary dsyplasia (BPD) is dexamethasone, which is associated with numerous side effects. Erythromycin treatment of Ureaplasma urealyticum has been ineffective in reducing BPD; are trials of azythromycin planned. Research may improve future outcomes by tailoring glucocorticoid dosage, duration and formulation in targeted populations and by developing agents to inhibit specific pro-inflammatory mechanisms.

The origins of cerebral palsy

PURPOSE OF REVIEW

Cerebral palsy is the most common and visible motor disability of childhood. Its aetiology remains a topic of hot debate between those who see it as a reflection of medical mismanagement of an avoidable complication and those who see its origins in the development of the fetal brain affected at many points along a causal pathway to damage. This review outlines the themes of research publications over the year 2004/2005.

RECENT FINDINGS

The review looks at recent findings relating to epidemiology, infection and inflammation, prematurity, multiple pregnancy, thrombophilias, genetics, placenta, neuroimaging and rescue therapies in cerebral palsy.

SUMMARY

Papers this year have helped clarify risk groups and identify some areas (e.g. the management of thrombophilias and the potential of induced hypothermia) with the potential to be rapidly introduced into clinical practice. In this enigmatic and multifactorial condition, however, progress remains slow. New tools such as magnetic resonance imaging are providing valuable insights into the lesions that result in cerebral palsy but the pathways to injury remain unclear. The future of cerebral palsy research lies in understanding the complex interactions of multiple factors on the road to cerebral palsy or in looking for final common pathways such as inflammation which may be amenable to manipulation.