Genes and environment in neonatal intraventricular hemorrhage

Periventricular hemorrhagic infarction in preterm neonates: Etiology and time of development

BACKGROUND

To find the obstetrical and delivery associated risk factors of antenatal and postnatal grade III intraventricular hemorrhage (IVH) or periventricular hemorrhagic infarction (PVHI) in preterm neonates.

METHODS

A retrospective study of obstetric and delivery associated risk factors included neonates (<35 gestational weeks) with severe IVH/PVHI (n = 120) and a prospectively collected control group (n = 50). The children were divided into: (1) antenatal onset group (n = 27) with insult visible on cerebral ultrasonography within the first 12 hours of birth or periventricular cystic changes visible in PVHI within the first 3 days; (2) neonatal onset group (n = 70) with insult diagnosed after initial normal findings or I-II grade IVH, and (3) unknown time-onset group (n = 23) with insult visible at > 12 h of age.

RESULTS

The mothers of the antenatal onset group had significantly more bacterial infections before delivery compared to the neonatal onset group: 20/27 (74.1%) versus 23/69 (33.3%), (odds ratio (OR) 5.7 [95% confidence interval 2.1-16]; p = 0.0008) or compared to the control group (11/50 (22%); OR 11 [2.8-42]; p = 0.0005). Placental histology revealed chorioamnionitis more often in the antenatal compared to the neonatal onset group (14/21 (66.7%) versus 16/42 (38.1%), respectively; OR 3.7 [1.18-11]; p = 0.025). Neonates with neonatal development of severe IVH/PVHI had significantly more complications during delivery or intensive care.

CONCLUSIONS

Bacterial infection during pregnancy is an important risk factor for development of antenatal onset severe IVH or PVHI. In neonates born to mothers with severe bacterial infection during pregnancy, cerebral ultrasonography is indicated for early detection of severe IVH or PVHI.

A Review of the Occurrence of Intraventricular Hemorrhage in Preterm Newborns and its Future Neurodevelopmental Consequences

Intraventricular hemorrhage (IVH) is a type of bleeding that occurs through the germinal matrix and comes through the ependymal cells into the ventricular cavity. It is mostly seen in preterm neonates but can also be seen sometimes in term neonates. Various factors predispose to preterm delivery; it can be spontaneous or medically induced. Spontaneous IVH occurs in cases of intrauterine infections in the mother, and it can be induced in cases of medical emergencies such as preeclampsia and eclampsia. The brain of a preterm newborn is not fully developed as it does not have pericytes and proteins, so it can bleed very quickly, which can cause IVH. Also, the vessels supplying the germinal matrix are immature and highly vascularized. IVH has four grades based on findings detected on cranial ultrasound and MRI. Management includes medical and surgical management; medical management includes phenobarbitone used for seizures and prophylaxis. Surgical management includes drainage, irrigation, and fibrinolytic therapy (DRIFT), and neuro-endoscopic lavage. IVH causes various short-term and long-term neurodevelopmental consequences. Long-term complications include cerebral palsy and intellectual disability, which hamper the life of the child. It mainly presents with seizures, flaccidity, decerebrate posture, etc. Various preventive measures can be taken to tackle IVH in newborns. First of all, preterm delivery should be avoided, and intrauterine infections in mothers should be treated. The administration of corticosteroids should be done for all preterm deliveries as it helps in the maturation of organs. The administration of magnesium sulfate should be done as it is neuroprotective and reduces cerebral palsy in the future. Delayed cord clamping is to be done to reduce recurrent blood transfusions and decrease the risk of IVH. This article explains the pathogenesis, management, prevention, and future outcomes of IVH.

High Prevalence of Collagenopathies in Preterm- and Term-Born Children With Periventricular Venous Hemorrhagic Infarction

INTRODUCTION

The aim of this study was to evaluate genetic risk factors in term-born children with antenatal periventricular hemorrhagic infarction (PVHI), presumed antenatal periventricular venous infarction and periventricular hemorrhagic infarction in preterm neonates.

METHODS

Genetic analysis and magnetic resonance imaging were performed in 85 children: term-born children (≥36 gestational weeks) with antenatal periventricular hemorrhagic infarction (n = 6) or presumed antenatal (n = 40) periventricular venous infarction and preterm children (<36 gestational weeks) with periventricular hemorrhagic infarction (n = 39). Genetic testing was performed using exome or large gene panel (n = 6700 genes) sequencing.

RESULTS

Pathogenic variants associated with stroke were found in 11 of 85 (12.9%) children with periventricular hemorrhagic infarction/periventricular venous infarction. Among the pathogenic variants, COL4A1/A2 and COL5A1 variants were found in 7 of 11 (63%) children. Additionally, 2 children had pathogenic variants associated with coagulopathy, whereas 2 other children had other variants associated with stroke. Children with collagenopathies had significantly more often bilateral multifocal stroke with severe white matter loss and diffuse hyperintensities in the white matter, moderate to severe hydrocephalus, moderate to severe decrease in size of the ipsilesional basal ganglia and thalamus compared to children with periventricular hemorrhagic infarction/periventricular venous infarction without genetic changes in the studied genes (P ≤ .01). Severe motor deficit and epilepsy developed more often in children with collagenopathies compared to children without genetic variants (P = .0013, odds ratio [OR] = 233, 95% confidence interval [CI]: 2.8-531; and P = .025, OR = 7.3, 95% CI: 1.3-41, respectively).

CONCLUSIONS

Children with periventricular hemorrhagic infarction/periventricular venous infarction have high prevalence of pathogenic variants in collagene genes (COL4A1/A2 and COL5A1). Genetic testing should be considered for all children with periventricular hemorrhagic infarction/periventricular venous infarction; COL4A1/A2 and COL5A1/A2 genes should be investigated first.

Impact of low-grade intraventricular hemorrhage on neurodevelopmental outcome in very preterm infants at two years of age

BACKGROUND

High-grade intraventricular hemorrhage (IVH) in very preterm infants is a known risk factor for adverse neurodevelopmental outcome. Prognosis is less clear for low-grade (grades I/II) IVH however, with conflicting study results in recent years.

OBJECTIVE

To evaluate the impact of low-grade IVH on neurodevelopmental outcome at 2 years corrected age in preterm infants born below 32 weeks gestation at the University hospital of Zurich between 2009 and 2014.

METHODS

Among 843 live-born preterm infants born during the observation period, 509 were included in our study. Exclusion criteria were death, high-grade IVH, cystic periventricular leukomalacia and congenital malformations. Infants were grouped into those with or without low-grade IVH according to cranial ultrasound. Neurodevelopmental impairment (NDI) was defined as cognitive or motor developmental score > 2 standard deviations below the mean and/or CP grades 2-5 and/or moderate/severe vision loss and/or hearing problem corrected with hearing aids. Multivariate linear regression was used to assess effect of low-grade IVH on endpoints while adjusting for other risk factors.

RESULTS

87 preterm infants had low-grade IVH (42 grade I, 45 grade II) on cranial ultrasound. These were compared to 422 preterm infants without IVH. Follow-up rate was 82.4 %. Preterm infants with low-grade IVH had higher rates of NDI (21.8 vs 13.3 %, p = 0.047). Infants with IVH grade II had significantly higher rates for CP (8.9 % vs 3.6 %, p = 0.003), visual impairment (20.5 % vs 8.3 %, p = 0.009) and NDI (33.3 % vs 13.3 %, p < 0.001).

CONCLUSION

In our study, low-grade IVH - and especially IVH grade II - is associated with adverse neurodevelopmental outcome at 2 years of corrected age.

Hemangioma-related gene polymorphisms in the pathogenesis of intraventricular hemorrhage in preterm infants

PURPOSE

The aim of this study was to evaluate the possible relationship between four single nucleotide polymorphisms of hemangioma-linked genes encoding for anthrax toxin receptor 1 (ANTXR1 G976A), R kinase insert domain receptor (KDR T1444C), adrenoceptor beta 2 (ADRB C79CG), and insulin-like growth factor 1 receptor (IGF-1R G3174A) and the occurrence of IVH in a population of preterm infants.

METHODS

The study includes a population of 105 infants born from 24 + 0 to 32 + 0 weeks of gestation and hospitalized at the Department of Neonatology (III level hospital) of Poznan University of Medical Science. Intraventricular hemorrhage was diagnosed with the use of cranial ultrasound. The classification of intraventricular bleeding was based on the Papile IVH classification.

RESULTS

The incidence of IVH was higher in infants with lower birth weight, lower APGAR scores, and low birth weight. The study revealed that IVH was approximately two times less likely to occur in infants with the allele G of IGF-1R 3174G > A.

CONCLUSION

Identifying susceptible premature infants through genetic analysis could be a potential way to alleviate severe IVH and its subsequent consequences. Further research examining a wider range of relevant gene polymorphisms could help highlight any genetic patterns in this deleterious bleeding complication.

Maternal Pyelonephritis as a Potential Cause of Perinatal Periventricular Venous Infarction in Term-Born Children

Introduction: The study was designed to assess the prevalence of pregnancy and delivery associated risk factors in children suffering from neonatal or presumed periventricular venous infarction. Methods: Antenatal records and pregnancy outcome data were retrospectively assessed in children with presumed periventricular venous infarction (n = 43, born ≥36 gestational weeks) or neonatal periventricular venous infarction (n = 86, born <36 gestational weeks) and compared to a matched control group (n = 2168, ≥36 gestational weeks) from a prospective study. Results: Children with presumed periventricular venous infarction had significantly more maternal bacterial infections compared to the control group (47% vs 20%, respectively, P < .001), whereas no difference was found compared to the neonatal periventricular venous infarction group (49%, P = .80). Mothers with bacterial infection in the presumed periventricular venous infarction group had significantly more often pyelonephritis compared to the control group (50% vs 3.4%, respectively, P < .001). Conclusions: Our data show an increased risk for developing periventricular venous infarction in the case of maternal bacterial infections, especially between gestational weeks 21 and 31.

THYROID DYSFUNCTION IN PREGNANCY: COMPARISON OF OUTCOMES IN INFANTS

The aim of this study was to compare the incidence of mild psychomotor delay in infants whose mothers were treated for thyroid dysfunction regardless of the cause during first trimester of pregnancy with those whose mothers did not use medications prenatally. The sample included 200 infants up to 4 months of age. Half of the infants were examined by a pediatric physiatrist, while the other half were chosen randomly from the primary pediatric clinic. Binary logistic regression was performed to assess the impact of factors on psychomotor delay. The model contained seven independent variables derived from bivariate analyses and clinical relevance. Results showed that the infant's chance of having psychomotor delay was 5.53 times higher if the mother had drug-compensated thyroid dysfunction. Younger gestational age increased the likelihood of delay 2.12 times per each gestational week. The likelihood of psychomotor delay also rose by 1% per 1 g of birth weight reduction. We found strong positive linear correlation between maternal drug-compensated thyroid dysfunction during pregnancy and psychomotor delay in infants, which has not been reported elsewhere. This differentiates an important and common prenatal risk factor and lays the foundation for faster initiation of habilitation of infants at risk. These insights provide a basis for planning the National Screening Program for Neurorisk Infants.

Recent Review of Germinal Matrix Hemorrhage-Intraventricular Hemorrhage in Preterm Infants

Germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) is a particular type of intracranial hemorrhage that affects the preterm population. GMH-IVH originates from bleeding within the highly vascular area near the center of the brain known as the germinal matrix. The pathogenesis of GMH-IVH is unclear; it is likely related to hemodynamic changes and fluctuations in cerebral blood flow within a fragile developing brain. Cranial ultrasound is the primary diagnostic test and reveals the degree of GMH-IVH based on a grading system. Management includes prevention of preterm delivery with meticulous antenatal and postnatal preventative strategies. This article discusses current evidence specific to the pathogenesis, risk factors, diagnosis, grading scales, and management approaches with GMH-IVH in preterm infants.

Intracranial Hemorrhage and 2-Year Neurodevelopmental Outcomes in Infants Born Extremely Preterm

OBJECTIVES

To determine the incidence, timing, progression, and risk factors for intracranial hemorrhage (ICH) in infants 24^0/7 to 27^6/7 weeks of gestational age and to characterize the association between ICH and death or neurodevelopmental impairment (NDI) at 2 years of corrected age.

STUDY DESIGN

Infants enrolled in the Preterm Erythropoietin Neuroprotection Trial had serial cranial ultrasound scans performed on day 1, day 7-9, and 36 weeks of postmenstrual age to evaluate ICH. Potential risk factors for development of ICH were examined. Outcomes included death or severe NDI as well as Bayley Scales of Infant and Toddler Development, 3rd Edition, at 2 years of corrected age.

RESULTS

ICH was identified in 38% (n = 339) of 883 enrolled infants. Multiple gestation and cesarean delivery reduced the risk of any ICH on day 1. Risk factors for development of bilateral Grade 2, Grade 3, or Grade 4 ICH at day 7-9 included any ICH at day 1; 2 or more doses of prenatal steroids decreased risk. Bilateral Grade 2, Grade 3, or Grade 4 ICH at 36 weeks were associated with previous ICH at day 7-9. Bilateral Grade 2, any Grade 3, and any Grade 4 ICH at 7-9 days or 36 weeks of postmenstrual age were associated with increased risk of death or severe NDI and lower Bayley Scales of Infant and Toddler Development, 3rd Edition, scores.

CONCLUSIONS

Risk factors for ICH varied by timing of bleed. Bilateral and increasing grade of ICH were associated with death or NDI in infants born extremely preterm.

Inflammatory biomarkers in very preterm infants during early intravenous paracetamol administration

BACKGROUND

Paracetamol promotes early closure of patent ductus arteriosus (PDA), and it may affect inflammation after preterm birth.

OBJECTIVE

The aim of this study was to evaluate the association between paracetamol treatment and serum inflammatory biomarkers in very preterm infants with respiratory distress.

STUDY DESIGN

The infants were randomly assigned to intravenous paracetamol or placebo during the first 4 days of life, and others received a lower dose of paracetamol unblinded. Serum samples were used for the analysis of 10 cytokines, C-reactive protein (CRP) and malondialdehyde (MDA). The impact of paracetamol on the biomarkers was evaluated, based on the levels during the early (<60 h) and the later (60-120 h) postnatal age.

RESULTS

Altogether, 296 serum samples from 31 paracetamol and 25 placebo group infants were analysed. Paracetamol had no effect on cytokine levels during the first 60 h when most induced PDA contractions took place. Later paracetamol treatment was associated with lower serum levels of several cytokines, including interleukin (IL-) 10, interferon gamma-induced protein (IP-) 10, and monocyte chemoattractant protein-1. CRP levels were lower in the paracetamol group during the early treatment. Amongst the infants who had severe morbidities, MDA was higher (p = .045), regardless of paracetamol treatment.

CONCLUSION

No significant differences in the cytokine levels were evident between the treatment and placebo groups. However, during early treatment, CRP levels were lower in the paracetamol group. To clarify whether this was due to a decrease in cardiopulmonary distress, or a distinct anti-inflammatory effect, requires further studies.

External ventricular drainage for posthemorrhagic ventricular dilatation in preterm infants: insights on efficacy and failure

OBJECTIVE

The objective of this study was to describe the clinical and neuroradiological characteristics of a cohort of preterm infants who had undergone external ventricular drain insertion as a temporary measure to treat posthemorrhagic ventricular dilatation. In addition, the authors investigated the factors predicting permanent shunt dependency.

METHODS

The authors retrospectively reviewed the medical records of a cohort of preterm infants who had undergone external ventricular drain insertion at Gaslini Children's Hospital (Genoa, Italy) between March 2012 and February 2018. They also analyzed clinical characteristics and magnetic resonance imaging data, including diffusion- and susceptibility-weighted imaging studies, which were obtained before both catheter insertion and removal.

RESULTS

Twenty-eight infants were included in the study. The mean gestational age was 28.2 ± 2.7 weeks, and the mean birth weight was 1209 ± 476 g. A permanent ventriculoperitoneal shunt was inserted in 15/28 (53.6%) infants because of the failure of external ventricular drainage as a temporary treatment option. Compared with the shunt-free group, the shunt-dependent group had a significantly lower gestational age (29.3 ± 2.3 vs 27.2 ± 2.7 weeks, p = 0.035) and tended toward a lower birth weight (p = 0.056). None of the clinical and neuroradiological characteristics significantly differed between the shunt-free and shunt-dependent groups at the time of catheter insertion. As expected, ventricular parameters as well as the intraventricular extension of intracerebral hemorrhage, as assessed using the intraventricular hemorrhage score, were reportedly higher in the shunt-dependent group than in the shunt-free group before catheter removal.

CONCLUSIONS

External ventricular drainage is a reliable first-line treatment for posthemorrhagic hydrocephalus. However, predicting its efficacy as a unique treatment remains challenging. A lower gestational age is associated with a higher risk of posthemorrhagic hydrocephalus progression, suggesting that the more undeveloped the mechanisms for the clearance of blood degradation products, the greater the risk of requiring permanent cerebrospinal fluid diversion, although sophisticated MRI investigations are currently unable to corroborate this hypothesis.

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.

Genetic predictors of severe intraventricular hemorrhage in extremely low-birthweight infants

OBJECTIVE

To test associations between grades 3 or 4 (severe) intraventricular hemorrhage (IVH) and single nucleotide polymorphisms (SNPs) associated with coagulation, inflammation, angiogenesis, and organ development in an exploratory study.

STUDY DESIGN

Extremely low-birthweight (ELBW) infants enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network's (NRN) Cytokines Study were included if they had cranial ultrasound (CUS) and genotyping data available in the NRN Anonymized DNA Repository and Database. Associations between SNPs and IVH severity were tested with multivariable logistic regression analysis.

RESULT

One hundred thirty-nine infants with severe IVH and 687 infants with grade 1 or 0 IVH were included. One thousand two hundred seventy-nine SNPs were genotyped. Thirteen were preliminarily associated with severe IVH including five related to central nervous system (CNS) neuronal and neurovascular development.

CONCLUSION

Genetic variants for CNS neuronal and neurovascular development may be associated with severe IVH in premature infants.

Elevated supine midline head position for prevention of intraventricular hemorrhage in VLBW and ELBW infants: a retrospective multicenter study

OBJECTIVE

To evaluate the impact of elevated supine midline head position on intraventricular hemorrhage (IVH) in very-low-birth-weight (VLBW) infants.

STUDY DESIGN

We reviewed data from four Level III/IV units. Two of these units (mid-line group) cared for infants in midline position and the other two (routine care group) provided routine care. We compared incidence of any and severe IVH in two groups using multivariate logistic regression analyses.

RESULTS

Of 2201 VLBW infants, 1041 were extremely-low-birth-weight (ELBW). Odds of any IVH were not different either for VLBW or ELBW infants. Odds of severe IVH were higher for VLBW infants in mid-line group (OR 1.43, 95% CI 1.007-2.02; p value 0.046) but not for ELBW infants (OR 0.9, 95% CI 0.6-1.4; p value 0.73).

CONCLUSIONS

The incidence of any IVH was similar in the two groups but the incidence of severe IVH was higher in VLBW infants in mid-line group.

"The First Thousand Days" Define a Fetal/Neonatal Neurology Program

Gene-environment interactions begin at conception to influence maternal/placental/fetal triads, neonates, and children with short- and long-term effects on brain development. Life-long developmental neuroplasticity more likely results during critical/sensitive periods of brain maturation over these first 1,000 days. A fetal/neonatal program (FNNP) applying this perspective better identifies trimester-specific mechanisms affecting the maternal/placental/fetal (MPF) triad, expressed as brain malformations and destructive lesions. Maladaptive MPF triad interactions impair progenitor neuronal/glial populations within transient embryonic/fetal brain structures by processes such as maternal immune activation. Destructive fetal brain lesions later in pregnancy result from ischemic placental syndromes associated with the great obstetrical syndromes. Trimester-specific MPF triad diseases may negatively impact labor and delivery outcomes. Neonatal neurocritical care addresses the symptomatic minority who express the great neonatal neurological syndromes: encephalopathy, seizures, stroke, and encephalopathy of prematurity. The asymptomatic majority present with neurologic disorders before 2 years of age without prior detection. The developmental principle of ontogenetic adaptation helps guide the diagnostic process during the first 1,000 days to identify more phenotypes using systems-biology analyses. This strategy will foster innovative interdisciplinary diagnostic/therapeutic pathways, educational curricula, and research agenda among multiple FNNP. Effective early-life diagnostic/therapeutic programs will help reduce neurologic disease burden across the lifespan and successive generations.

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

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

Role of Fibronectin-1 polymorphism genes with the pathogenesis of intraventricular hemorrhage in preterm infants

BACKGROUND/INTRODUCTION

Intraventricular hemorrhage (IVH) is a dangerous complication facing a significant proportion of preterm infants. It is multifactorial in nature, and an observed fibronectin deficiency in the germinal matrix basal lamina is among the most prominent factors that influence such rupture. Better understanding of the FN1 gene polymorphisms and their role in IVH may further clarify the presence of a genetic susceptibility of certain babies to this complication. The aim of this study was to assess if 5 single nucleotide polymorphisms of the fibronectin gene may be linked to an increased incidence of IVH.

MATERIAL AND METHODS

The study included 108 infants born between 24 and 32 weeks of gestation. IVH was diagnosed using cranial ultrasound performed on the 1st,3rd, and 7th day after birth and classified according to Papile et al. IVH classification. The 5 FN1 gene polymorphisms assessed in the study were the following: rs3796123; rs1968510; rs10202709; rs6725958; and rs35343655.

RESULTS

IVH developed in 51 (47.2%) out of the 108 preterm infants. This includes, 18 (35.3%) with stage I IVH, 19 (37.3%) with stage II, 11 (21.6%) with stage III, and 3 (5.9%) with stage IV IVH. Incidence of IVH was higher in infants with lower APGAR scores, low gestational age, and low birthweight. Analysis showed that IVH stage II to IV was approximately seven times more likely to occur in infants with the genotype TT FN1 rs10202709 (OR 7237 (1046-79.59; p = 0,044)). No other significant association was found with the rest of the polymorphisms.

CONCLUSION

The results of our study indicate a sevenfold increased genetic susceptibility to IVH in preterm infants with the TT FN1 rs10202709 gene polymorphism. The fibronectin gene polymorphism may therefore be of crucial importance as a genetic risk factor for IVH in preterm infants. Further studies are warranted.

Intraventricular Hemorrhage in Very Preterm Infants: A Comprehensive Review

Germinal matrix-intraventricular-intraparenchymal hemorrhage (GMH-IVH-IPH) is a major complication of very preterm births before 32 weeks of gestation (WG). Despite progress in clinical management, its incidence remains high before 27 WG. In addition, severe complications may occur such as post-hemorrhagic hydrocephalus and/or periventricular intraparenchymal hemorrhage. IVH is strongly associated with subsequent neurodevelopmental disabilities. For this review, an automated literature search and a clustering approach were applied to allow efficient filtering as well as topic clusters identification. We used a programmatic literature search for research articles related to intraventricular hemorrhage in preterms that were published between January 1990 and February 2020. Two queries ((Intraventricular hemorrhage) AND (preterm)) were used in PubMed. This search resulted in 1093 articles. The data manual curation left 368 documents that formed 12 clusters. The presentation and discussion of the clusters provide a comprehensive overview of existing data on the pathogenesis, complications, neuroprotection and biomarkers of GMH-IVH-IPH in very preterm infants. Clinicians should consider that the GMH-IVH-IPH pathogenesis is mainly due to developmental immaturity of the germinal matrix and cerebral autoregulation impairment. New multiomics investigations of intraventricular hemorrhage could foster the development of predictive biomarkers for the benefit of very preterm newborns.

Pilot study to establish a prospective neonatal cohort: Study of Preterm Infants and Neurodevelopmental Genes (SPRING)

BACKGROUND

Genetic risk variants and preterm birth are early and potent risk factors for later neuropsychiatric disorders. To understand the interrelationships between these factors, a large-scale genetic study of very preterm (VPT, <32 weeks gestation) infants with prospective follow-up is required. In this paper, we describe a streamlined study approach, using efficient processes for biological and clinical data collection, to feasibly establish such a cohort.

METHODS

We sought to recruit 500 VPT families within a 1 year period from neonatal units. Treating clinical teams recruited eligible participants, obtained parent consent, collected blood samples and posted specimens to the research laboratory. We extracted all clinical data from the National Neonatal Research Database, an existing UK resource that captures daily patient-level data on all VPT infants.

RESULTS

Between May 2017 and June 2018, we established a cohort of 848 VPT infants and their parents from 60 English neonatal units. The study population (median (IQR), gestation: 28.9 (26-30) weeks; birth weight: 1120 (886-1420) g) represented 18.9% of eligible infants born at the study sites during the recruitment period (n=4491). From the subset of 521 complete family trios, we successfully completed genotyping for 510 (97.9%) trios. Of the original 883 infants whose parents consented to participate, the parents of 796 (90.1%) infants agreed to future data linkage and 794 (89.9%) agreed to be recalled.

CONCLUSION

We demonstrate the feasibility and acceptability of streamlined strategies for genetic, neonatal and longitudinal data collection and provide a template for future cost-effective and efficient cohort development.

Apolipoprotein E gene polymorphisms and intraventricular haemorrhage in infants born preterm: a large prospective multicentre cohort study

AIM

Infants born preterm are at risk of intraventricular haemorrhage (IVH) but individual susceptibility related to genes is not well defined in this vulnerable population. Apolipoprotein genotypes APOE2 and APOE4 increase the hazard of cerebral haemorrhages in adults. We investigated whether APOE is associated with prevalence of IVH and is likely to have a particular genotype.

METHOD

In this prospective study, 5075 infants born preterm with genotype APOE3 were compared to 965 (APOE2) and 1912 (APOE4) individuals, to analyse the association between APOE genotype and grade III and IV IVH. We used a logistic regression model including gestational age, antenatal steroid treatment, 5-minute Apgar scores less than 3, intubation, pneumothorax, small for gestational age, multiple birth, sex, and maternal descent as independent factors.

RESULTS

The APOE2 (20.1%) and APOE4 (19.8%) genotypes were significantly more prevalent in infants with IVH than in those with the APOE3 haplotype (17.4%) (APOE2: odds ratio [OR] 1.33, 95% confidence interval [CI] 1.00-1.76; APOE4: OR 1.39, 95% CI 1.12-1.74). Infants with two polymorphisms had the highest risk of IVH (8.7%; OR 1.63, 95% CI 1.09-2.45).

INTERPRETATION

APOE2 and APOE4 genotypes are relevant risk factors for IVH in infants born preterm. Our findings improve our understanding of the genetic contributions to IVH.

Genetic variants associated with patent ductus arteriosus in extremely preterm infants

OBJECTIVE

Patent ductus arteriosus (PDA) is a commonly observed condition in preterm infants. Prior studies have suggested a role for genetics in determining spontaneous ductal closure. Using samples from a large neonatal cohort we tested the hypothesis that common genetic variations are associated with PDA in extremely preterm infants.

STUDY DESIGN

Preterm infants (n = 1013) enrolled at NICHD Neonatal Research Network sites were phenotyped for PDA. DNA was genotyped for 1634 single nucleotide polymorphisms (SNPs) from candidate genes. Analyses were adjusted for ancestral eigenvalues and significant epidemiologic variables.

RESULTS

SNPs in several genes were associated with the clinical diagnosis of PDA and with surgical ligation in extremely preterm neonates diagnosed with PDA (p < 0.01). None of the associations were significant after correction for multiple comparisons.

CONCLUSION

We identified several common genetic variants associated with PDA. These findings may inform further studies on genetic risk factors for PDA in preterm infants.

Lack of relationship between cord blood erythropoietin and intraventricular hemorrhage in premature neonates: a controversial result

PURPOSE

The aim of this study was to assess the incidence and risk factors of intraventricular hemorrhage (IVH) as well as the role of cord blood erythropoietin (EPO) level in predicting the possibility of IVH in premature neonates.

MATERIALS AND METHODS

This prospective study included 140 preterm neonates born at hospitals affiliated to Shiraz University of Medical Sciences from May 2014 to April 2015. Complete blood count and cord blood EPO level was measured after birth. Brain ultrasonography was performed at 3 and 7-10 days after birth in these newborns.

RESULTS

Brain ultrasonography showed IVH in 8.57% (12/140) until the third day and 20% (28/140) at 7-10 days of life in premature neonates. Early gestational age, low birth weight, low Apgar score, and failure to give prenatal steroid were significant risk factors for developing IVH. The mean level of cord blood EPO was 20.95 ± 21.09 mIU/mL in premature newborns without IVH and 15.82 ± 17.11 mIU/mL with IVH. There was no correlation between the cord blood EPO and IVH in premature newborns.

CONCLUSION

Antenatal steroids therapy should be encouraged among women at risk of premature delivery. Our results showed that the cord blood EPO was not correlated with IVH in preterm neonates and further research is required to assess this relationship.

Successful implementation of an intracranial hemorrhage (ICH) bundle in reducing severe ICH: a quality improvement project

OBJECTIVE

Our specific, measurable, attainable, relevant, and time-limited (SMART) aim was to reduce the incidence of severe intracranial hemorrhage (ICH) among preterm infants born <30 weeks' gestation from a baseline of 24% (January 2012-December 2013) to a long-term average of 11% by December 2015.

STUDY DESIGN

We instituted an ICH bundle consisting of elements of the "golden hour" (delayed cord clamping, optimized cardiopulmonary resuscitation, improved thermoregulation) and provision of cluster care in the neonatal intensive care unit (NICU). We identified key drivers to achieve our SMART aims, and implemented quality improvement (QI) cycles: initiation of the ICH bundle, education of NICU staff, and emphasis on sustained adherence. We excluded infants born outside our facility and those with congenital anomalies.

RESULTS

Using statistical process control analysis (p-chart), the ICH bundle was associated with successful reduction in severe ICH (grade 3-4) in our NICU from a prebundle rate of 24% (January 2012-December 2013) to a sustained reduction over the next 4 years to an average rate of 9.7% by December 2017. Results during 2016-2017 showed a sustained improvement beyond the goal for 2014-2015. Over the same interval, there was improvement in admission temperatures [median 36.1 °C (interquartile range: 35.3-36.7 °C) vs. 37.1 °C (36.8-37.5 °C), p < 0.01] and a decrease in mortality rate [pre: 16/117 (14%) vs. post: 16/281 (6%), P < 0.01].

CONCLUSION

Our multidisciplinary QI initiative decreased severe ICH in our institution from a baseline rate of 24% to a lower rate of 9.7% over the ensuing 4 years. Intensive focus on sustained implementation of an ICH bundle protocol consisting of improved delivery room management, thermoregulation, and clustered care in the NICU was temporally associated with a clinically significant reduction in severe ICH.

Surgical necrotizing enterocolitis in extremely premature neonates is associated with genetic variations in an intergenic region of chromosome 8

BackgroundTwin studies suggest that genetic factors may account for up to 50% increased risk for necrotizing enterocolitis (NEC), but genome-wide association studies for NEC are lacking.MethodsGenotyping was done on Illumina BeadChip, followed by analysis using PLINK with logistic regression under an additive model.ResultsAmong 751 extremely-low-birth-weight (<1,000 g, >401 g) neonates, 30 had surgical NEC. Two hundred and sixty-one single-nucleotide polymorphisms (SNPs) showed association with NEC at P<0.05, of which 35 were significant at P<10-7. Minor allele(s) in a cluster of SNPs spanning a 43-kb region of chromosome 8 (8q23.3) conferred an odds ratio of 4.72 (95% confidence interval (CI): 2.51-8.88) for elevated risk of NEC. Two smaller clusters on chromosome 14 and chromosome 11 exhibited P values of 10-7-10-8. The chromosome 8 cluster is in an intergenic region between CUB and Sushi multiple domains 3 (-1.43 Mb) and trichorhinophalangeal syndrome I (+542 kb). RNA sequencing in this region identified a potential novel open-reading frame corresponding to a long interspersed element-1 retrotransposable element.ConclusionGenetic variation in an intergenic region of chromosome 8 is associated with increased risk for NEC with a mechanism that is yet to be identified.

Maternal, fetal and perinatal factors associated with necrotizing enterocolitis in Sweden. A national case-control study

OBJECTIVE

To analyze associations of maternal, fetal, gestational, and perinatal factors with necrotizing enterocolitis in a matched case-control study based on routinely collected, nationwide register data.

STUDY DESIGN

All infants born in 1987 through 2009 with a diagnosis of necrotizing enterocolitis in any of the Swedish national health care registers were identified. For each case up to 6 controls, matched for birth year and gestational age, were selected. The resulting study population consisted of 720 cases and 3,567 controls. Information on socioeconomic data about the mother, maternal morbidity, pregnancy related diagnoses, perinatal diagnoses of the infant, and procedures in the perinatal period, was obtained for all cases and controls and analyzed with univariable and multivariable logistic regressions for the whole study population as well as for subgroups according to gestational age.

RESULTS

In the study population as a whole, we found independent positive associations with necrotizing enterocolitis for isoimmunization, fetal distress, cesarean section, neonatal bacterial infection including sepsis, erythrocyte transfusion, persistent ductus arteriosus, cardiac malformation, gastrointestinal malformation, and chromosomal abnormality. Negative associations were found for maternal weight, preeclampsia, maternal urinary infection, premature rupture of the membranes, and birthweight. Different patterns of associations were seen in the subgroups of different gestational age.

CONCLUSION

With some interesting exceptions, especially in negative associations, the results of this large, population based study, are in keeping with earlier studies. Although restrained by the limitations of register data, the findings mirror conceivable pathophysiological processes and underline that NEC is a multifactorial disease.

The significance of polymorphisms in genes encoding Il-1β, Il-6, TNFα, and Il-1RN in the pathogenesis of intraventricular hemorrhage in preterm infants

INTRODUCTION

Intraventricular hemorrhage (IVH) is a significant morbidity seen in very low birth weight infants. Genes related to inflammation may be risk factors for IVH.

MATERIAL AND METHODS

We examined five polymorphisms for an association with IVH in 100 preterm infants born from singleton pregnancy, before 32 + 0 weeks of gestation, exposed to antenatal steroid therapy, and without congenital abnormalities. These polymorphisms include interleukin-1β 3953 C>T, interleukin-6 -174G>C and -596G>A, tumor necrosis factor -308 G>A, and 86 bp variable number tandem repeat polymorphism of interleukin-1 receptor antagonist (Il -1RN 86 bp VNTR).

RESULTS

In our study population, 45 (45%) infants developed IVH, including 15 (33.33%) with stage 1, 19 (42.22%) with stage 2, 8 (17.77%) with stage 3, and 3 (6.66%) with stage 4. In contrast to the previously published data, the prevalence of IVH did not vary between infants with different IL-6 and TNFα alleles and genotypes. Our novel investigations in Il-1 +3953 C>T and Il-1RN 86 bp VNTR polymorphism did not show any significant link between those alleles or genotypes and IVH.

CONCLUSIONS

IVH is a significant problem for preterm infants. In addition to little progress in preventing IVH in preterm babies, substantial research that are focused on understanding the etiology, mechanism and risk factors for IVH are imperative. In the era of personalized medicine, identification of genetic risk factors creates opportunities to generate preventative strategies. Further studies should be performed to confirm the role of genetic factors in etiology and pathogenesis of IVH.

Intravenous injection of umbilical cord-derived mesenchymal stromal cells attenuates reactive gliosis and hypomyelination in a neonatal intraventricular hemorrhage model

Intraventricular hemorrhage (IVH) is a frequent complication of preterm newborns, resulting in cerebral palsy and cognitive handicap as well as hypoxic ischemic encephalopathy and periventricular leukomalacia. In this study, we investigated the restorative effect on neonatal IVH by umbilical cord-derived mesenchymal stromal cells (UC-MSCs) cultured in serum-free medium (RM medium) for clinical application. UC-MSCs were cultured with αMEM medium supplemented with FBS or RM. A neonatal IVH mouse model at postnatal day 5 was generated by intraventricular injection of autologous blood, and mice were intravenously administered 1×10⁵ UC-MSCs two days after IVH. Brain magnetic resonance imaging was performed at postnatal day 15, 22 and neurological behavioral measurements were performed at postnatal day 23, accompanied by histopathological analysis and cytokine bead assays in serum after IVH with or without UC-MSCs. Both UC-MSCs cultured with αMEM and RM met the criteria of MSCs and improved behavioral outcome of IVH mice. Moreover the RM group exhibited significant behavioral improvement compared to the control group. Histopathological analysis revealed UC-MSCs cultured with RM significantly attenuated periventricular reactive gliosis, hypomyelination, and periventricular cell death observed after IVH. Furthermore, human brain-derived neurotrophic factor and hepatocyte growth factor were elevated in the serum, cerebrospinal fluid and brain tissue of neonatal IVH model mice 24h after UC-MSCs administration. These results suggest UC-MSCs attenuate neonatal IVH by protecting gliosis and apoptosis of the injured brain, and intravenous injection of UC-MSCs cultured in RM may be feasible for neonatal IVH in clinic.

Prevention and management of bronchopulmonary dysplasia: Lessons learned from the neonatal research network

Despite remarkable improvements in survival of extremely premature infants, the burden of BPD among survivors remains a frustrating problem for parents and caregivers. Advances, such as antenatal steroids and surfactant replacement, which have dramatically improved survival, have not reduced BPD among survivors. Other advances that have significantly improved the combined outcome of death or BPD, such as vitamin A and avoidance of mechanical ventilation, have had smaller magnitude effects on the outcome of BPD alone. Postnatal steroids have a clear beneficial effect on BPD, but the optimal preparation, dose, and timing for maximizing benefit and minimizing harm have yet to be determined. This persistent burden of BPD among the most immature survivors remains a challenge for the NRN and other researchers in neonatal medicine.

Correlation of preterm infant illness severity with placental histology

INTRODUCTION

A major goal of neonatal medicine is to identify neonates at highest risk for morbidity and mortality. Previously, we developed PhysiScore (Saria et al., 2010), a novel tool for preterm morbidity risk prediction. We now further define links between overall individual morbidity risk, specific neonatal morbidities, and placental pathologies.

METHODS

102 placentas, including 38 from multiple gestations, were available from the previously defined PhysiScore cohort (gestational age ≤ 34 weeks and birth weight ≤ 2000 g). Placentas were analyzed for gross and histologic variables including maternal malperfusion, amniotic fluid infection sequence, chronic inflammation, and fetal vascular obstruction. Risk as determined by PhysiScore and recorded neonatal morbidities were tested for statistical association with placental findings.

RESULTS

In pair-wise correlations, respiratory distress syndrome, bronchopulmonary dysplasia, acute hemodynamic instability, post-hemorrhagic hydrocephalus, culture-positive sepsis, and necrotizing enterocolitis each significantly correlated with at least one placenta histology variable. Amniotic fluid infection sequence (p = 0.039), specifically the fetal inflammatory response (p = 0.017), correlated with higher PhysiScores (greater morbidity) but was not independent of gestational age and birth weight. In multivariate analyses correlating variables with all nine morbidities, gestational age (p < 0.001), placental size <10th percentile (p = 0.031), full thickness perivillous fibrin deposition (p = 0.001), and amniotic fluid infection sequence (umbilical arteritis, p = 0.031; ≥2 chorionic plate vessels with vasculitis, p = 0.0125), each were significant associations.

DISCUSSION

Amniotic fluid infection sequence plays a significant role in neonatal morbidity. Less neonatal morbidity was observed in older and heavier infants and those with small placental size and full thickness perivillous fibrin deposition. The combined assessment of placental gross and histologic findings together with physiologic risk evaluation may allow more precise prediction of neonatal morbidity risk soon after delivery.