Intrauterine Inflammation and the Onset of Peri-Intraventricular Hemorrhage in Premature Infants

Occurrence and Time of Onset of Intraventricular Hemorrhage in Preterm Neonates: A Systematic Review and Meta-Analysis of Individual Patient Data

Importance

Intraventricular hemorrhage (IVH) has been described to typically occur during the early hours of life (HOL); however, the exact time of onset is still unknown.

Objective

To investigate the temporal distribution of IVH reported in very preterm neonates.

Data Sources

PubMed, Embase, Cochrane Library, and Web of Science were searched on May 9, 2024.

Study Selection

Articles were selected in which at least 2 cranial ultrasonographic examinations were performed in the first week of life to diagnose IVH. Studies with only outborn preterm neonates were excluded.

Data Extraction And Synthesis

Data were extracted independently by 3 reviewers. A random-effects model was applied. This study is reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. The Quality in Prognostic Studies 2 tool was used to assess the risk of bias.

Main Outcomes And Measures

The overall occurrence of any grade IVH and severe IVH among preterm infants was calculated along with a 95% CI. The temporal distribution of the onset of IVH was analyzed by pooling the time windows 0 to 6, 0 to 12, 0 to 24, 0 to 48, and 0 to 72 HOL. A subgroup analysis was conducted using studies published before and after 2007 to allow comparison with the results of a previous meta-analysis.

Results

A total of 21 567 records were identified, of which 64 studies and data from 9633 preterm infants were eligible. The overall rate of IVH did not decrease significantly before vs after 2007 (36%; 95% CI, 30%-42% vs 31%; 95% CI, 25%-36%), nor did severe IVH (10%; 95% CI, 7%-13% vs 11%; 95% CI, 8%-14%). The proportion of very early IVH (up to 6 HOL) after 2007 was 9% (95% CI, 3%-23%), which was 4 times lower than before 2007 (35%; 95% CI, 24%-48%). IVH up to 24 HOL before and after 2007 was 44% (95% CI, 31%-58%) and 25% (95% CI, 15%-39%) and up to 48 HOL was 82% (95% CI, 65%-92%) and 50% (95% CI, 34%-66%), respectively.

Conclusion And Relevance

This systematic review and meta-analysis found that the overall prevalence of IVH in preterm infants has not changed significantly since 2007, but studies after 2007 showed a later onset as compared with earlier studies, with only a small proportion of IVHs occurring before 6 HOL.

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.

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.

Interobserver reliability between pediatric radiologists and residents in ultrasound evaluation of intraventricular hemorrhage in premature infants

BACKGROUND

Germinal matrix intraventricular hemorrhage (IVH) may contribute to significant morbidity and mortality in premature infants. Timely identification and grading of IVH affect decision-making and clinical outcomes. There is possibility of misinterpretation of the ultrasound appearances, and the interobserver variability has not been investigated between radiology resident and board-certified radiologist.

AIM

To assess interobserver reliability between senior radiology residents performing bedside cranial ultrasound during on-call hours and pediatric radiologists.

METHODS

From June 2018 to June 2020, neonatal cranial ultrasound examinations were performed in neonatal intensive care unit. Ultrasound findings were recorded by the residents performing the ultrasound and the pediatric attending radiologists.

RESULTS

In total, 200 neonates were included in the study, with a mean gestational age of 30.9 wk. Interobserver agreement for higher grade (Grade III & IV) IVH was excellent. There was substantial agreement for lower grade (Grade I & II) IVH.

CONCLUSION

There is strong agreement between radiology residents and pediatric radiologists, which is higher for high grade IVHs.

Every Country, Every Woman, Every Child; Group B Streptococcal Disease Worldwide Prematurity modifies the risk of long-term neurodevelopmental impairments after invasive Group B Streptococcus infections during infancy in Denmark and the Netherlands

Background

Preterm birth and neonatal infections are both associated with mortality and long-term neurodevelopmental impairments (NDIs). We examined whether the effect of invasive group B Streptococcus disease (iGBS) on mortality and long-term NDI differs for preterm and term infants, and whether co-occurrence of iGBS and prematurity leads to worse outcome.

Methods

Nationwide cohort studies of children with a history of iGBS were conducted using Danish and Dutch medical databases. Comparison cohorts of children without iGBS were matched on birth year/month, sex, and gestational age. Effects of iGBS on all-cause mortality and NDI were analyzed using Cox proportional hazards and logistic regression. Effect modification by prematurity was evaluated on additive and multiplicative scales.

Results

We identified 487 preterm and 1642 term children with a history of iGBS and 21 172 matched comparators. Dutch preterm children exposed to iGBS had the highest mortality rate by 3 months of age (671/1000 [95% CI, 412–929/1000] person-years). Approximately 30% of this mortality rate could be due to the common effect of iGBS and prematurity. Preterm children with iGBS had the highest NDI risk (8.8% in Denmark, 9.0% in the Netherlands). Of this NDI risk 36% (Denmark) and 60% (the Netherlands) might be due to the combined effect of iGBS and prematurity.

Conclusions

Prematurity is associated with iGBS development. Our study shows that it also negatively impacts outcomes of children who survive iGBS. Preterm infants would benefit from additional approaches to prevent maternal GBS colonization, as this decreases risk of both preterm birth and iGBS.

Placental pathology and intraventricular hemorrhage in preterm and small for gestational age infants

OBJECTIVE

The aim of this study was to examine the relationship between chorioamnionitis and vascular malperfusion on placental pathology and intraventricular hemorrhage (IVH) in premature and small for gestational age (SGA) infants.

STUDY DESIGN

A retrospective analysis of 263 infants ≤34 weeks gestation or ≤1800 g and their mothers was conducted by chart review for placental pathology and clinical data from 2014 to 2018. Unadjusted and adjusted odds ratios (OR) for the association of placental pathology with IVH were calculated.

RESULT

Unadjusted OR showed an association between acute chorioamnionitis and IVH, but logistic regression analysis showed a non-significant adjusted OR between acute or chronic chorioamnionitis with IVH. Maternal vascular malperfusion was significantly associated with increased IVH when controlling for confounders.

CONCLUSION

Placental maternal vascular malperfusion is associated with the development of IVH in premature and SGA infants when controlling for other confounders.

Intraventricular hemorrhage in preterm babies

Germinal matrix-intraventricular hemorrhage (GM-IVH) is a major complication of prematurity and inversely associated with gestational age and birth weight. The hemorrhage originates from the germinal matrix with an immature capillary bed where vascularization is intense and active cell proliferation is high. It occurs in around 20% of very low-birth-weight preterm neonates. Germinal matrix-intraventricular hemorrhage is less common in females, the black race, and with antenatal steroid use, but is more common in the presence of mechanical ventilation, respiratory distress, pulmonary bleeding, pneumothorax, chorioamnionitis, asphyxia, and sepsis. Ultrasonography is the diagnostic tool of choice for intraventricular hemorrhage and its complications. Approximately 25-50% of the germinal matrix-intraventricular hemorrhage cases are asymptomatic and diagnosed during routine screening. These cases are usually patients with low-grade hemorrhage. Neurologic findings are prominent in severe intraventricular hemorrhage cases. The major complications of the germinal matrix-intraventricular hemorrhage in preterm babies are periventricular hemorrhagic infarction, posthemorrhagic ventricular dilatation, periventricular leukomalacia, and cerebellar hemorrhage. It is an important cause of mortality and morbidity. The management of hemodynamics and ventilation of patients, appropriate follow-up, and early diagnosis and treatment can minimize morbidity. Prognosis in intraventricular hemorrhage is related to the severity of bleeding, parenchymal damage, and the presence of seizures and shunt surgery. The main determinant of prognosis is periventricular hemorrhagic infarction and its severity. Moderate-severe intraventricular hemorrhage can cause posthemorrhagic hydrocephalus, cerebral palsy, and mental retardation. Even mild germinal matrix-intraventricular hemorrhage can result in developmental disorders. Long-term problems such as neurodevelopmental disorders and cerebral palsy are as important as short-term problems. Improving the quality of life of these babies should be aimed through appropriate treatment and follow-up. In this review, intraventricular hemorrhage and complications are discussed.

Lipopolysaccharide-induced changes in the neurovascular unit in the preterm fetal sheep brain

Background

Exposure to inflammation during pregnancy can predispose to brain injury in premature infants. In the present study, we investigated the effects of prolonged exposure to inflammation on the cerebrovasculature of preterm fetal sheep.

Methods

Chronically instrumented fetal sheep at 103–104 days of gestation (full term is ~ 147 days) received continuous low-dose lipopolysaccharide (LPS) infusions (100 ng/kg over 24 h, followed by 250 ng/kg/24 h for 96 h plus boluses of 1 μg LPS at 48, 72, and 96 h) or the same volume of normal saline (0.9%, w/v). Ten days after the start of LPS exposure at 113–114 days of gestation, the sheep were killed, and the fetal brain perfused with formalin in situ. Vessel density, pericyte and astrocyte coverage of the blood vessels, and astrogliosis in the cerebral cortex and white matter were determined using immunohistochemistry.

Results

LPS exposure reduced (P < 0.05) microvascular vessel density and pericyte vascular coverage in the cerebral cortex and white matter of preterm fetal sheep, and increased the activation of perivascular astrocytes, but decreased astrocytic vessel coverage in the white matter.

Conclusions

Prolonged exposure to LPS in preterm fetal sheep resulted in decreased vessel density and neurovascular remodeling, suggesting that chronic inflammation adversely affects the neurovascular unit and, therefore, could contribute to long-term impairment of brain development.

Outcomes of Bone Marrow Mononuclear Cell Transplantation for Neurological Sequelae Due to Intracranial Hemorrhage Incidence in the Neonatal Period: Report of Four Cases

Aim: The aim of this study was to present primary outcomes of autologous bone marrow mononuclear cell (BMMNC) transplantation to improve neurological sequelae in four children with intracranial hemorrhage (ICH) incidence during the neonatal period. Methods: GMFM88 and modified Ashworth score were used to assess motor function and muscle spasticity before BMMNC transplantation and after transplantation. Brain MRI was performed to evaluate brain morphology before and after BMMNC transplantation. Bone marrow were harvested from anterior iliac crest puncture and BMMNCs were isolated using Ficoll gradient centrifugation. The microbiological testing, cell counting, and hematopoietic stem cell (hHSC CD34+ cell) analysis were performed, following which BMMNCs were infused intrathecally. Results: Improvement in motor function was observed in all patients after transplantation. In addition, muscle spasticity was reduced in all four patients. Conclusion: Autologous BMMNC transplantation may improve motor function and reduce muscle spasticity in children with ICH incidence during the neonatal period.

Components of the antepartum, intrapartum, and postpartum exposome impact on distinct short-term adverse neonatal outcomes of premature infants: A prospective cohort study

We aimed to test the hypothesis that determinants of the perinatal clinical exposome related to the underlying etiology of premature birth (PTB) impact differently on select neonatal outcomes. We conducted a prospective longitudinal study of 377 singleton preterm neonates [gestational age (GA) at birth: 23-34 weeks] separated into three distinct contemporaneous newborn cohorts: i) spontaneous PTB in the setting of intra-amniotic infection/inflammation (yes-IAI, n = 116); ii) spontaneous PTB in the absence of IAI (no-IAI, n = 130), and iii) iatrogenic PTB for preeclampsia (iPTB-PE, n = 131). Newborns (n = 372) were followed until death or discharge. Amniotic fluid defensins 1&2 and calgranulins A&C were used as biomarkers of IAI. An algorithm considering cord blood interleukin-6 (IL-6) and haptoglobin (Hp switch-on) was used to assess fetal exposure to IAI. Intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), necrotizing enterocolitis (NEC), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), early-onset neonatal (EONS) and late-onset (LOS) sepsis, death. Independent risk factors for adverse outcomes were: i) IVH (n = 53): histologic chorioamnionitis, GA, fetal growth restriction, male sex, Hp switch-on; ii) PVL (n = 11): cord blood IL-6; iii) NEC (n = 25), GA; iv) BPD (n = 53): ventilator support, need for surfactant, GA; v) ROP (n = 79): ventilator support, Hp switch-on, GA; vi) fetal and neonatal death (n = 31): GA, amniotic fluid IL-6; vii) suspect EONS (n = 92): GA, Hp switch-on; viii) LOS (n = 81): GA. Our findings are applicable to pregnancies delivered between 23 and 34 weeks' gestation in the setting of IAI and PE, and suggest that GA and inflammatory intrauterine environment play key roles in occurrence of IVH, PVL, ROP, death, EONS and LOS. Postnatal determinants seem to play major role in NEC and BPD.

Chorioamnionitis Is a Risk Factor for Intraventricular Hemorrhage in Preterm Infants: A Systematic Review and Meta-Analysis

Although chorioamnionitis (CA) is a well-known risk factor for white matter disease of prematurity, the association with intraventricular hemorrhage (IVH) is controversial and has not been yet systematically reviewed. We performed a systematic review and meta-analysis of studies exploring the association between CA and IVH. A comprehensive literature search was conducted using PubMed/MEDLINE and EMBASE, from their inception to 1 July 2017. Studies were included if they examined preterm infants and reported primary data that could be used to measure the association between exposure to CA and the presence of IVH. A random-effects model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). We found 1,284 potentially relevant studies, of which 85 met the inclusion criteria (46,244 infants, 13,432 CA cases). Meta-analysis showed that CA exposure was significantly associated with all grades IVH (OR 1.88, 95% CI 1.61-2.19), with grades 1-2 IVH (OR 1.69, 95% CI 1.22-2.34), and with grades 3-4 IVH (OR 1.62, 95% CI 1.42-1.85). Both clinical and histological CA were associated with an increased risk for developing IVH in very preterm infants. In contrast, the presence of funisitis did not increase IVH risk when compared to CA in the absence of funisitis (OR 1.22, 95% CI 0.89-1.67). Further meta-analyses confirmed earlier findings that CA-exposed infants have significantly lower gestational age (GA; mean difference [MD] -1.20 weeks) and lower birth weight (BW; MD -55 g) than the infants not exposed to CA. However, meta-regression and subgroup analysis could not demonstrate an association between the lower GA and BW and the risk of IVH in the CA-exposed infants. In conclusion, our data show that CA is a risk factor for IVH, but also a risk factor for greater prematurity and more clinical instability. In contrast to other complications of prematurity, such as patent ductus arteriosus, retinopathy of prematurity, or bronchopulmonary dysplasia, the effect of CA on IVH appears to be independent of CA as causative factor for very preterm birth.

Intrauterine inflammation, cerebral oxygen consumption and susceptibility to early brain injury in very preterm newborns

BACKGROUND

In utero exposure to inflammation results in elevated cerebral oxygen consumption. This increased metabolic demand may contribute to the association between chorioamnionitis and intraventricular haemorrhage (P/IVH). We hypothesised that intrauterine inflammation imposes an elevated cerebral metabolic load and increased fractional oxygen extraction (cFTOE) with cFTOE further increased in the presence of early P/IVH.

METHODS

Eighty-three infants ≤30 weeks gestation were recruited. Exposure to intrauterine inflammation was determined by placental histology. Total internal carotid blood flow (Doppler ultrasound) and near infrared spectroscopy were measured and cerebral oxygen delivery (mcerbDO2), consumption (mcerbVO2) and cFTOE were calculated on days 1 and 3 of life. Primary outcome was defined as death or P/IVH >grade II (cranial sonograph) by day 3.

RESULTS

Infants exposed to intrauterine inflammation had higher total internal carotid blood flow (92 vs 63 mL/kg/min) and mcerbDO2 (13.7 vs 10.1 mL/kg/min) than those not exposed to inflammation. Newborns with P/IVH had both higher oxygen consumption and extraction compared with those without sonographic injury regardless of exposure to intrauterine inflammation. Further, in preterms exposed to inflammation, those with P/IVH had higher consumption (6.1 vs 4.8 mL/kg/min) and extraction than those without injury. These differences were observed only on day 1 of life.

CONCLUSIONS

Although P/IVH is multifactorial in preterm newborns, it is likely that cerebral hypoxic-ischaemia plays a central pathophysiological role. These data provide a mechanistic insight into this process and suggests that the increased cerebral metabolic load imposed by the presence of inflammation results in a higher risk of critical hypoxic ischaemia in the preterm with increased susceptibility to significant P/IVH.

A Systematic Review and Meta-analysis of the Timing of Early Intraventricular Hemorrhage in Preterm Neonates: Clinical and Research Implications

A considerable number of intraventricular hemorrhages (IVH) occur within the first hours of life (HOL). Temporality between IVH and its antecedents as well as a consistent definition of "early IVH" is lacking in a large and growing body of literature. We performed a systematic review of prospective studies that reported onset of IVH in preterm neonates within the first HOL and afterwards. The English literature was searched using three databases up to March 2013. Four timing periods of IVH can be compared in 16 identified studies: 0-6; 7-12; 13-24; after 24 HOL. The 0-6 and after 24 HOL were the major modes of IVH timing. Pooled IVH proportions were estimated through a meta-analysis of studies that were conducted after antenatal steroid and surfactant era. In neonates weighing ≤1500 g at birth: 48% of IVH (95% CI: 42-58%, 5 studies, 279 IVH cases) occurred during 0-6 HOL and 38% (95% CI: 19-57%, 4 studies, 241 IVH cases) after 24 HOL. The 0-6 HOL is the shortest, most vulnerable period for IVH, thus, an early IVH is an IVH occurs in it. Such early IVH had prognostic, etiological/preventive and medicolegal implications. Accordingly, preterm neonates at risk of IVH should have their first routine screening head ultrasound at about 6 HOL. Future research exploring the antecedents of IVH should guaranty the temporality between these antecedents and IVH. Additional research will be required to determine whether the long term neurological outcomes of early and late IVH are the same.

Incidence of brain injuries in premature infants with gestational age ≤ 34 weeks in ten urban hospitals in China

BACKGROUND

There is a large number (1.5 million per year) of premature births in China. It is necessary to obtain the authentic incidences of intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL), the common brain injuries, in Chinese premature infants. The present multicenter study aimed to investigate the incidence of brain injuries in premature infants in ten urban hospitals in China.

METHODS

The research proposal was designed by the Subspecialty Group of Neonatology of Pediatric Society of the Chinese Medical Association. Ten large-scale urban hospitals voluntarily joined the multicenter investigation. All premature infants with a gestational age ≤ 34 weeks in the ten hospitals were subjected to routine cranial ultrasound within three days after birth, and then to repeated ultrasound every 3-7 days till their discharge from the hospital from January 2005 to August 2006. A uniform data collection sheet was designed to record cases of brain injuries.

RESULTS

The incidences of overall IVH and severe IVH were 19.7% (305/1551) and 4.6% (72/1551), respectively with 18.4% (56/305) for grade 1, 58.0% (177/305) for grade 2, 17.7% (54/305) for grade 3 and 5.9% (18/305) for grade 4 in nine hospitals. The incidences of overall PVL and cystic PVL were 5.0% (89/1792) and 0.8% (14/1792) respectively, with 84.3% (75/89) for grade 1, 13.5% (12/89) for grade 2, and 2.2% (2/89) for grade 3 in the ten hospitals. The statistically significant risk factors that might aggravate the severity of IVH were vaginal delivery (OR=1.883, 95% CI: 1.099-3.228, P=0.020) and mechanical ventilation (OR=4.150, 95% CI: 2.384-7.223, P=0.000). The risk factors that might result in the development of cystic PVL was vaginal delivery (OR=21.094, 95% CI: 2.650-167.895, P=0.000).

CONCLUSIONS

The investigative report can basically reflect the incidence of brain injuries in premature infants in major big cities of China. Since more than 60% of the Chinese population live in the rural areas of China, it is expected to undertake a further multicenter investigation covering the rural areas in the future.

Neutrophil defensins but not interleukin-6 in vaginal fluid after preterm premature rupture of membranes predict fetal/neonatal inflammation and infant neurological impairment

OBJECTIVE

To determine whether neutrophil defensins (HNP1-3) and interleukin-6 (IL-6) in vaginal fluid after preterm premature rupture of membranes predict fetal inflammatory response syndrome (FIRS), neurological impairment or chorioamnionitis.

DESIGN

Prospective study.

SETTING

Tertiary referral university hospital.

POPULATION

Forty-two patients with preterm premature rupture of membranes at <32 weeks.

METHODS

Levels of HNP1-3 and IL-6 were measured in vaginal fluid obtained by swabs. Mann-Whitney U-test was used to compare HNP1-3 and IL-6 levels in groups with vs. without FIRS, infant death or neurological impairment, and chorioamnionitis (p<0.05 significant). Logistic regression was used to control for potential confounders. Diagnostic accuracies of HNP1-3 and IL-6 were determined by receiver operator characteristics analysis.

MAIN OUTCOME MEASURES

Fetal inflammatory response syndrome was defined as neonatal inflammation within 72 hours postpartum. Neurological impairment was defined as motor and/or tone abnormalities at one year of corrected age. Chorioamnionitis was diagnosed histologically.

RESULTS

Levels of HNP1-3, but not IL-6, were higher in 12 cases of FIRS (p=0.019 and p=0.256, respectively). Levels of HNP1-3, but not IL-6, were higher in 14 cases of infant death or neurological impairment (p=0.015 and p=0.100, respectively) and, when only survivors were analyzed, in nine cases of neurological impairment (p=0.030 and p=0.187, respectively). Levels of HNP1-3 and IL-6 were higher in 29 cases of chorioamnionitis (p=0.005 and p=0.003, respectively). The differences remained significant after adjustment for gestational age. Levels of HNP1-3 predicted FIRS, infant death or neurological impairment and chorioamnionitis with an area under the curve of 0.75, 0.79 and 0.78, respectively.

CONCLUSIONS

Elevated vaginal fluid HNP1-3 and IL-6 levels are associated with histological chorioamnionitis. Elevated HNP1-3 can also identify FIRS and predict infant death or neurological impairment.

Necrotizing enterocolitis in infants with periventricular hemorrhagic infarction: associations and outcomes

BACKGROUND

Necrotizing enterocolitis (NEC) and periventricular hemorrhagic infarction (PVHI) are complications of prematurity associated with poor neurodevelopmental outcomes.

OBJECTIVES

We characterized temporal and causal associations between NEC and type of PVHI as well as associations with outcomes.

METHODS

This was a multicenter retrospective study of infants with birth weight <1,500 g and diagnosis of PVHI by a pediatric radiologist at 3 neonatal intensive care units in North Carolina, USA, between January 1998 and December 2004. NEC was confirmed using radiological and surgical pathology findings. Infants were assessed by 3 years using the Bayley Scales of Infant Development, second edition.

RESULTS

35 of 112 (31%) of study patients developed NEC. NEC was diagnosed subsequent to PVHI by a median of 16.6 days (95% CI [9.5, 24.9], p < 0.0001). Indomethacin use and the presence of bilateral PVHI were associated with an increased risk of subsequent NEC (OR 2.8, 95% CI [1.1, 7.2] and OR 2.4, 95% CI [1.1, 5.7], respectively). Having bilateral versus unilateral PVHI was associated with a 2.34-fold increased risk of death (95% CI [1.27, 4.33], p = 0.007). NEC was not associated with worse motor outcomes in this population. Overall, the probability of a mental development index >70 was greatest for infants with unilateral PVHI versus bilateral PVHI, although the presence of NEC was associated with worse cognitive outcomes in both groups.

CONCLUSIONS

Premature infants with PVHI often subsequently develop NEC, especially if they have bilateral PVHI and are exposed to indomethacin. While NEC results in worse neurodevelopmental outcomes, PVHI severity appears more important to the outcome of these infants.

Cord blood erythropoietin and interleukin-6 for prediction of intraventricular hemorrhage in the preterm neonate

OBJECTIVE

To evaluate cord blood erythropoietin (EPO) and interleukin-6 (IL-6) levels to predict preterm infants at risk of developing intraventricular hemorrhage (IVH).

METHODS

Levels of umbilical cord EPO, acid-base status and IL-6 were analyzed in 116 consecutive, preterm newborns (GA at delivery: 29 [23-34 ] weeks) born to mothers who had a clinically indicated amniocentesis to rule out infection. Early-onset neonatal sepsis (EONS) was diagnosed using symptoms, hematological criteria and blood cultures.

RESULTS

IVH was diagnosed by cranial ultrasounds. The prevalence of IVH in our population was 25% (29/116). There was a direct relationship between cord blood EPO and cord blood IL-6 concentration (r = 0.225, p = 0.014), independent of GA at birth. Elevated cord blood EPO levels (r = 0.182, p = 0.016) and GA at birth (r =  -0.236, p = 0.004) remained significant independent factors associated with the risk of IVH, when evaluated with stepwise logistic regression analyses. Cord blood IL-6, pH, and EONS were not associated with IVH. These relationships remained following correction for GA at birth (p = 0.027).

CONCLUSIONS

Our results suggest that elevation in cord blood EPO may predict newborns at risk for IVH, independent of fetal inflammatory status. Further studies are warranted to confirm this association.

Chemokine CCL18 predicts intraventricular hemorrhage in very preterm infants

BACKGROUND

Intraventricular hemorrhage (IVH) in very preterm infants is a common disease associated with long-term consequences. Risk factors of IVH remain to be further defined.

AIMS

To determine whether specific immunoproteins at birth predict the risk of IVH and whether their receptors are localized at the bleeding site.

METHODS

A prospective cohort consisted of 163 infants born before 32 weeks of gestation. Altogether 107 cord blood immunoproteins and 12 cytokines from peripheral blood obtained 1 and 7 days after birth were analyzed. Serial brain ultrasounds were assessed. Immunohistochemistry of a chemokine receptor from 14 autopsies was studied.

RESULTS

Low levels of cord chemokine CCL18 (chemokine (C-C motif) ligand 18) robustly predicted the risk of IVH grade II-IV when ante- and neonatal risk factors were considered. Cord CCL18 increased from 32 weeks to term. During the first week after very preterm birth CCL18 increased as the risk of new IVH cases decreased. CCL18 receptor, CCR3, was detectable in choroid plexus, periventricular capillary endothelium, ependymal cells, and in germinal matrix.

CONCLUSION

Low cord blood CCL18 is an independent risk factor of IVH. CCL18 may inhibit signal transduction of its receptor in periventricular cells. Defining the function and regulation of CCL18 may help to decrease the risk of IVH.

Outcome of early-onset sepsis in a national cohort of very low birth weight infants

BACKGROUND

Early-onset sepsis (EOS) is associated with significant morbidity and mortality among infants with a very low birth weight (VLBW); however, there is a sparse amount of complete data on large cohorts.

OBJECTIVE

To evaluate the mortality and major morbidities among VLBW infants with EOS.

METHODS

This was a population-based observational study. Data were prospectively collected by the Israel Neonatal Network on all VLBW infants born in Israel from 1995 through 2005. Univariate and multivariable analyses were performed to assess the independent association of EOS on morbidity and mortality of VLBW infants.

RESULTS

The study cohort included 15 839 infants, of whom 383 (2.4%) developed EOS. EOS was associated with significantly increased odds for mortality (odds ratio [OR]: 2.57 [95% confidence interval (CI): 1.97-3.35]), severe intraventricular hemorrhage (OR: 2.24 [95% CI: 1.67-3.00]), severe retinopathy of prematurity (OR: 2.04 [95% CI: 1.32-3.16]), and bronchopulmonary dysplasia (OR: 1.74 [95% CI: 1.24-2.43]). EOS was associated with an increased risk of death and/or severe neurologic morbidity (OR: 2.92 [95% CI: 2.27-3.80]).

CONCLUSIONS

Although only 2.4% of VLBW infants had an episode of EOS, these infants were at an approximately threefold excess risk of death or major neurologic morbidities.

Risk factors for periventricular-intraventricular hemorrhage in premature infants

Periventricular-intraventricular hemorrhage (PV-IVH) is a major cause of neurological disabilities in preterm newborns. This study aimed to determine the perinatal factors associated with PV-IVH. We conducted a retrospective case-control study from preterm infants born at < or =34 weeks of gestation and admitted to Neonatal Intensive Care Units of Seoul National University Children's Hospital and Seoul National University Bundang Hospital between June 2003 and December 2007. Neonates with no cranial sonographic data or infants transferred from other centers after three days of age were excluded. Of 1,044 eligible subjects, 59 infants with PV-IVH grade 2, 3, and 4 were allocated to the case group. The control group consisted of 118 infants without PV-IVH who were matched for gestational age and birth weight to each case of PV-IVH. At the multivariate logistic regression model, metabolic acidosis (odds ratio [OR]: 6.94; 95% confidence interval [CI]: 1.12-43.23) and use of inotropes (OR: 3.70; 95% CI: 1.16-11.84) were associated with an increased risk of PV-IVH. Maternal use of antenatal corticosteroids decreases the risk of PV-IVH (OR: 0.36; 95% CI: 0.14-0.92).

The relationship between systemic hemodynamic perturbations and periventricular-intraventricular hemorrhage--a historical perspective

Periventricular-intraventricular hemorrhage (PV-IVH) remains the major cause of injury to the developing brain. Predisposing factors include a germinal matrix with an immature vasculature, a pressure passive cerebral circulation, and hemodynamic perturbations in sick premature infants. Intact cerebral autoregulation has been documented in stable premature infants; however, it functions within a limited blood pressure range and is likely to be absent in the sick hypotensive infant, which increases the risk for PV-IVH with perturbations in blood pressure. The risk for PV-IVH is markedly increased in the absence of antenatal glucocorticoid exposure in the intubated low birthweight infant <1000 g with respiratory distress syndrome; +/- other complications. Although surfactant administration reduces the severity of respiratory distress syndrome, it has not led to a reduction in PV-IVH. Early postnatal administration of indomethacin has been associated with a reduction in PV-IVH, although this has not translated into long-term neurocognitive benefits.

The role of systemic hemodynamic disturbances in prematurity-related brain injury

Premature infants who experience cerebrovascular injury frequently have acute and long-term neurologic complications. In this article, we explore the relationship between systemic hemodynamic insults and brain injury in this patient population and the mechanisms that might be at play.

Using proteomics in perinatal and neonatal sepsis: hopes and challenges for the future

PURPOSE OF REVIEW

Particularities of the fetal immune response to infection cause a heightened inflammatory state that acts synergistically with microbial insult to induce damage. Proteomics offers the opportunity for detecting fetuses at risk of sepsis and neurological injury.

RECENT FINDINGS

Molecular tools (16S-rRNA) demonstrate that the diversity of microbial agents of intra-amniotic infection exceeds what is suspected clinically or is documented by cultures. The resulting inflammatory process has the potential to damage the fetus in utero. Stepwise algorithms (mass restricted score) have been developed to extract proteomic profiles characteristic of amniotic fluid inflammation. The mass restricted score includes four proteomic biomarkers: defensin-2, defensin-1, S100A12, and S100A8 proteins. Other amniotic fluid biomarkers relevant for preterm birth are S100A9 and insulin-like growth factor-binding protein 1. S100A12 - ligand for the receptor of advanced glycation end products - has the strongest association with histological chorioamnionitis and funisitis. Presence of S100A12 and S100A8 in amniotic fluid is predictive of early-onset neonatal sepsis and poor neurodevelopmental outcome.

SUMMARY

Presence of amniotic fluid proteomic biomarkers of inflammation is associated with increased inflammatory status of the fetus at birth. Future challenges are to find biomarkers that provide insight into molecular mechanisms of chronic fetal and neonatal cellular damage and to identify candidates for early neuroprotection strategies.

Fetal inflammatory response in women with proteomic biomarkers characteristic of intra-amniotic inflammation and preterm birth

OBJECTIVE

To determine the relationship between presence of amniotic fluid (AF) biomarkers characteristic of inflammation (defensins 2 and 1 and calgranulins C and A) and fetal inflammatory status at birth.

DESIGN

Prospective observational cohort.

SETTING

Tertiary referral University hospital.

POPULATION

One hundred and thirty-two consecutive mothers (gestational age, median [interquartile range]: 29.6 [24.1-33.1] weeks) who had a clinically indicated amniocentesis to rule out infection and their newborns.

METHODS

Intra-amniotic inflammation was diagnosed by mass spectrometry surface-enhanced-laser-desorption-ionization time of flight (SELDI-TOF). The AF proteomic fingerprint (mass-restricted [MR] score) ranges from 0-4 (none to all biomarkers present). The intensity of intra-amniotic inflammation was graded based on the number of proteomic biomarkers: MR score 0: 'no' inflammation, MR score 1-2: 'minimal' inflammation and MR score 3-4: 'severe' inflammation. At birth, cord blood was obtained for all women. Severity of histological chorioamnionitis and early-onset neonatal sepsis (EONS) was based on established histological and haematological criteria. Interleukin-6 (IL-6) levels were measured by sensitive immunoassays. The cord blood-to-AF IL-6 ratio was used as an indicator of the differential inflammatory response in the fetal versus the AF compartment.

MAIN OUTCOME MEASURES

To relate proteomic biomarkers of intra-amniotic infection to cord blood IL-6 and to use the latter as the primary marker of fetal inflammatory response.

RESULTS

Women with intra-amniotic inflammation delivered at an earlier gestational age (analysis of variance, P<0.001) and had higher AF IL-6 levels (P<0.001). At birth, neonates of women with severe intra-amniotic inflammation had higher cord blood IL-6 levels (P=0.002) and a higher frequency of EONS (P=0.002). EONS was characterised by significantly elevated cord blood IL-6 levels (P<0.001). Of the 39 neonates delivered by mothers with minimal intra-amniotic inflammation, 15 (39%) neonates had umbilical cord blood IL-6 levels above the mean for the group and 2 neonates had confirmed sepsis. The severity of the neutrophilic infiltrate in the chorionic plate (P<0.001), choriodecidua (P=0.002), umbilical cord (P<0.001) but not in the amnion (P>0.05) was an independent predictor of the cord blood-to-AF IL-6 ratio. Relationships were maintained following correction for gestational age, birthweight, amniocentesis-to-delivery interval, caesarean delivery, status of the membranes, race, MR score and antibiotics and steroid exposure.

CONCLUSIONS

We provide evidence that presence of proteomic biomarkers characteristic of inflammation in the AF is associated with an increased inflammatory status of the fetus at birth. Neonates mount an increased inflammatory status and have positive blood cultures even in the context of minimal intra-amniotic inflammation.

Neonatal cerebral oxygenation is not linked to foetal vasculitis and predicts intraventricular haemorrhage in preterm infants

AIM

The aim of the study was to compare the cerebral tissue oxygenation index (c-TOI) measured by near infrared spectroscopy (NIRS) in infants with and without foetal vasculitis.

METHODS

Twenty-four infants with placental signs of a foetal inflammatory response (FIR), foetal vasculitis, were compared with 39 controls. NIRS examination was done within the first 24 h.

RESULTS

Infants with FIR had a significant lower gestational age (26.8 +/- 2.4 vs. 29.8 +/- 2.4 weeks' gestation; p < 0.01), Hb (9.4 +/- 1.2 vs. 10.9 +/- 1.5 mM; p < 0.01) and blood P(CO2) (5.5 +/- 0.8 vs. 6.3 +/- 1.1 kPa, p < 0.01) compared to controls. There was no significant difference in arterial blood pressure, inspiratory oxygen content, needs of mechanical ventilation or c-TOI (73.6 +/- 8.1% vs. 73.9 +/- 8.1% (p = 0.9)). The effect of FIR on c-TOI was -0.3% (95% CI -3.9 to 4.5%). This result was not affected by inclusion of potential confounders in the analysis. Eight infants subsequently developed intra/periventricular haemorrhage: four with minor lesions and four with severe lesions. There was a significant negative correlation between the severity of the intraventricular haemorrhage and the cerebral oxygenation (p = 0.002).

CONCLUSION

Cerebral oxygenation was not affected in the first day of life in preterm infants born with foetal vasculitis, while cerebral oxygenation in infants that later developed intraventricular haemorrhage was impaired.

iNKT cells in allergic disease

Recent studies indicate that invariant TCR+ CD1d-restricted natural killer T (iNKT) cells play an important role in regulating the development of asthma and allergy. iNKT cells can function to skew adaptive immunity toward Th2 responses, or can act directly as effector cells at mucosal surfaces in diseases such as ulcerative colitis and bronchial asthma. In mouse models of asthma, NKT cell-deficient strains fail to develop allergen-induced airway hyperreactivity (AHR), a cardinal feature of asthma, and NKT cells are found in the lungs of patients with chronic asthma, suggesting a critical role for NKT cells in the development of AHR. However, much work remains in characterizing iNKT cells and their function in asthma, and in understanding the relationship between the iNKT cells and conventional CD4+ T cells.