Degree of Uncertainty in Reporting Imaging Findings for Necrotizing Enterocolitis: A Secondary Analysis from a Pilot Randomized Diagnostic Trial

Diagnosis of necrotizing enterocolitis (NEC) relies heavily on imaging, but uncertainty in the language used in imaging reports can result in ambiguity, miscommunication, and potential diagnostic errors. To determine the degree of uncertainty in reporting imaging findings for NEC, we conducted a secondary analysis of the data from a previously completed pilot diagnostic randomized controlled trial (2019-2020). The study population comprised sixteen preterm infants with suspected NEC randomized to abdominal radiographs (AXRs) or AXR + bowel ultrasound (BUS). The level of uncertainty was determined using a four-point Likert scale. Overall, we reviewed radiology reports of 113 AXR and 24 BUS from sixteen preterm infants with NEC concern. The BUS reports showed less uncertainty for reporting pneumatosis, portal venous gas, and free air compared to AXR reports (pneumatosis: 1 [1-1.75) vs. 3 [2-3], p < 0.0001; portal venous gas: 1 [1-1] vs. 1 [1-1], p = 0.02; free air: 1 [1-1] vs. 2 [1-3], p < 0.0001). In conclusion, we found that BUS reports have a lower degree of uncertainty in reporting imaging findings of NEC compared to AXR reports. Whether the lower degree of uncertainty of BUS reports positively impacts clinical decision making in infants with possible NEC remains unknown.

Current Patterns of Probiotic Use in U.S. Neonatal Intensive Care Units: A Multi-Institution Survey

OBJECTIVE

 Probiotic supplementation is associated with health benefits in preterm infants. The 2021 American Academy of Pediatrics (AAP) statement on probiotic use advised caution, citing heterogeneity and absence of federal regulation. We assessed the impact of the AAP statement and current institution-wide patterns of probiotic use across neonatal intensive care units (NICU) across the United States.

STUDY DESIGN

 A cross-sectional web-based institutional survey using REDCap was emailed to 430 Children's Hospital Neonatal Consortium (CHNC) and Pediatrix Medical Group institutions. The survey captured data on probiotic formulations, supplementation, initiation and cessation criteria, reasons for discontinuation, interest in initiating, and AAP statement's impact.

RESULTS

 Ninety-five (22.1%) hospitals, including 42/46 (91%) CHNC and 53/384 (14%) Pediatrix institutions, completed the survey. Thirty-seven (39%) currently use probiotics. Fourteen different probiotic formulations were reported. The common criteria for initiation were birth weight <1,500 g and gestational age <32 weeks. Parental consent or assent was obtained at only 30% of institutions. Five hospitals (11%) with prior probiotic use discontinued solely due to the AAP statement. Overall, 23 (24%) of hospitals indicated that the AAP statement significantly influenced their decision regarding probiotic use. Nineteen of 51 nonusers (37%) are considering initiation.

CONCLUSION

 Probiotic use in preterm infants is likely increasing in NICUs across the United States, but significant variability exists. The 2021 AAP statement had variable impact on NICUs' decision regarding probiotic use. The growing interest in adopting probiotics and the significant interhospital variability highlight the need for better regulation and consensus guidelines to ensure standardized use.

KEY POINTS

· Probiotic use in preterm infants is likely increasing in U.S. NICUs, but clinical variability exists.. · The AAP statement on probiotic use in preterm infants had a modest impact on current practices.. · There's a need for better product regulation and consensus guidelines to ensure standardized use..

The Detrimental Effects of Peripartum Antibiotics on Gut Proliferation and Formula Feeding Injury in Neonatal Mice Are Alleviated with Lactobacillus rhamnosus GG

Peripartum antibiotics can negatively impact the developing gut microbiome and are associated with necrotizing enterocolitis (NEC). The mechanisms by which peripartum antibiotics increase the risk of NEC and strategies that can help mitigate this risk remain poorly understood. In this study, we determined mechanisms by which peripartum antibiotics increase neonatal gut injury and evaluated whether probiotics protect against gut injury potentiated by peripartum antibiotics. To accomplish this objective, we administered broad-spectrum antibiotics or sterile water to pregnant C57BL6 mice and induced neonatal gut injury to their pups with formula feeding. We found that pups exposed to antibiotics had reduced villus height, crypt depth, and intestinal olfactomedin 4 and proliferating cell nuclear antigen compared to the controls, indicating that peripartum antibiotics impaired intestinal proliferation. When formula feeding was used to induce NEC-like injury, more severe intestinal injury and apoptosis were observed in the pups exposed to antibiotics compared to the controls. Supplementation with the probiotic Lactobacillus rhamnosus GG (LGG) reduced the severity of formula-induced gut injury potentiated by antibiotics. Increased intestinal proliferating cell nuclear antigen and activation of the Gpr81-Wnt pathway were noted in the pups supplemented with LGG, suggesting partial restoration of intestinal proliferation by probiotics. We conclude that peripartum antibiotics potentiate neonatal gut injury by inhibiting intestinal proliferation. LGG supplementation decreases gut injury by activating the Gpr81-Wnt pathway and restoring intestinal proliferation impaired by peripartum antibiotics. Our results suggest that postnatal probiotics may be effective in mitigating the increased risk of NEC associated with peripartum antibiotic exposure in preterm infants.

Necrotizing enterocolitis in premature infants-A defect in the brakes? Evidence from clinical and animal studies

A key aspect of postnatal intestinal adaptation is the establishment of symbiotic relationships with co-evolved gut microbiota. Necrotizing enterocolitis (NEC) is the most severe disease arising from failure in postnatal gut adaptation in premature infants. Although pathological activation of intestinal Toll-like receptors (TLRs) is believed to underpin NEC pathogenesis, the mechanisms are incompletely understood. We postulate that unregulated aberrant TLR activation in NEC arises from a failure in intestinal-specific mechanisms that tamponade TLR signaling (the brakes). In this review, we discussed the human and animal studies that elucidate the developmental mechanisms inhibiting TLR signaling in the postnatal intestine (establishing the brakes). We then evaluate evidence from preclinical models and human studies that point to a defect in the inhibition of TLR signaling underlying NEC. Finally, we provided a framework for the assessment of NEC risk by screening for signatures of TLR signaling and for NEC prevention by TLR-targeted therapy in premature infants.

Early antibiotics and risk for necrotizing enterocolitis in premature infants: A narrative review

While prompt initiation of antibiotics at birth due to concerns for early onset sepsis is common, it often leads to many preterm infants being exposed to treatment despite negative blood cultures. Such exposure to early antibiotics can impact the developing gut microbiome putting infants at increased risk of several diseases. Necrotizing enterocolitis (NEC), a devastating inflammatory bowel disease that affects preterm infants, is among the most widely studied neonatal disease that has been linked to early antibiotics. While some studies have demonstrated an increased risk of NEC, other studies have demonstrated seemingly contrary findings of decreased NEC with early antibiotics. Studies using animal models have also yielded differing findings of benefit vs. harm of early antibiotic exposure on subsequent NEC susceptibility. We thus sought to conduct this narrative review to help clarify the relationship between early antibiotics exposure and future risk of NEC in preterm infants. Our objectives are to: (1) summarize findings from human and animal studies that investigated the relationship between early antibiotics and NEC, (2) highlight important limitations of these studies, (3) explore potential mechanisms that can explain why early antibiotics may increase or decrease NEC risk, and (4) identify future directions for research.

Chronic lung disease in full-term infants: Characteristics and neonatal intensive care outcomes in infants referred to children's hospitals

OBJECTIVE

To describe characteristics, outcomes, and risk factors for death or tracheostomy with home mechanical ventilation in full-term infants with chronic lung disease (CLD) admitted to regional neonatal intensive care units.

STUDY DESIGN

This was a multicenter, retrospective cohort study of infants born ≥37 weeks of gestation in the Children's Hospitals Neonatal Consortium.

RESULTS

Out of 67,367 full-term infants admitted in 2010-2016, 4886 (7%) had CLD based on receiving respiratory support at either 28 days of life or discharge. 3286 (67%) were still hospitalized at 28 days receiving respiratory support, with higher mortality risk than those without CLD (10% vs. 2%, p < 0.001). A higher proportion received tracheostomy (13% vs. 0.3% vs. 0.4%, p < 0.001) and gastrostomy (30% vs. 1.7% vs. 3.7%, p < 0.001) compared to infants with CLD discharged home before 28 days and infants without CLD, respectively. The diagnoses and surgical procedures differed significantly between the two CLD subgroups. Small for gestational age, congenital pulmonary, airway, and cardiac anomalies and bloodstream infections were more common among infants with CLD who died or required tracheostomy with home ventilation (p < 0.001). Invasive ventilation at 28 days was independently associated with death or tracheostomy and home mechanical ventilation (odds ratio 7.6, 95% confidence interval 5.9-9.6, p < 0.0001).

CONCLUSION

Full-term infants with CLD are at increased risk for morbidity and mortality. We propose a severity-based classification for CLD in full-term infants. Future work to validate this classification and its association with early childhood outcomes is necessary.

Effect of Various Preterm Infant Milk Formulas on NEC-Like Gut Injury in Mice

Formula feeding is an important risk factor for the development of necrotizing enterocolitis in preterm infants. The potential harmful effects of different preterm formulas on the developing intestinal tract remain incompletely understood. Here we demonstrate that feeding newborn mouse pups with various preterm formulas resulted in differing effects on intestinal inflammation, apoptosis, and activation of the pro-inflammatory transcription factor NFκB. 16S rRNA sequencing revealed that each preterm formula resulted in significant gut microbial alterations that were different from dam-fed controls. Formula feeding with EleCare and Similac Special Care caused greater intestinal injury compared to NeoSure. Pre-treatment with Lactobacillus rhamnosus GG ameliorated severity of intestinal injury from EleCare and Similac Special Care. Our findings indicate that not all preterm formulas are the same, and different formulations can have varying effects on intestinal inflammation, apoptosis, and microbiome composition.

Corticosteroid response predicts bronchopulmonary dysplasia status at 36 weeks in preterm infants treated with dexamethasone: A pilot study

IMPORTANCE

A major barrier to therapeutic development in neonates is a lack of standardized drug response measures that can be used as clinical trial endpoints. The ability to quantify treatment response in a way that aligns with relevant downstream outcomes may be useful as a surrogate marker for new therapies, such as those for bronchopulmonary dysplasia (BPD).

OBJECTIVE

To construct a measure of clinical response to dexamethasone that was well aligned with the incidence of severe BPD or death at 36 weeks' postmenstrual age.

DESIGN

Retrospective cohort study.

SETTING

Level IV Neonatal Intensive Care Unit.

PARTICIPANTS

Infants treated with dexamethasone for developing BPD between 2010 and 2020.

MAIN OUTCOME(S) AND MEASURE(S)

Two models were built based on demographics, changes in ventilatory support, and partial pressure of carbon dioxide (pCO₂ ) after dexamethasone administration. An ordinal logistic regression and regularized binary logistic model for the composite outcome were used to associate response level to BPD outcomes defined by both the 2017 BPD Collaborative and 2018 Neonatal Research Network definitions.

RESULTS

Ninety-five infants were treated with dexamethasone before 36 weeks. Compared to the baseline support and demographic data at the time of treatment, changes in ventilatory support improved ordinal model sensitivity and specificity. For the binary classification, BPD incidence was well aligned with risk levels, increasing from 16% to 59%.

CONCLUSIONS AND RELEVANCE

Incorporation of response variables as measured by changes in ventilatory parameters and pCO₂ following dexamethasone administration were associated with downstream outcomes. Incorporating drug response phenotype into a BPD model may enable more rapid development of future therapeutics.

Imaging for Diagnosis and Assessment of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is inflammatory bowel necrosis of preterm and critically ill infants. The disease is seen in 6-10% of preterm infants who weigh less than 1500 g at birth and carries considerable morbidity, mortality, and healthcare cost burden. Efforts focused on timely mitigation remain restricted due to challenges in early diagnosis as clinical features, and available laboratory tests remain nonspecific until late in the disease. There is renewed interest in the radiological and sonographic assessment of intestinal diseases due to technological advances making them safe, cost-efficient, and supporting Web-based transmission of images, thereby reducing time to diagnosis by disease experts. Most of our experience has been with plain abdominal radiography, which shows characteristic features such as pneumatosis intestinalis in up to 50-60% of patients. Many patients with advanced disease may also show features such as portal venous gas and pneumoperitoneum. Unfortunately, these features are not seen consistently in patients with early, treatable conditions, and hence, there has been an unfulfilled need for additional imaging modalities. In recent years, abdominal ultrasound (AUS) has emerged as a readily available, noninvasive imaging tool that may be a valuable adjunct to plain radiographs for evaluating NEC. AUS can allow real-time assessment of vascular perfusion, bowel wall thickness, with higher sensitivity in detecting pneumatosis, altered peristalsis, and characteristics of the peritoneal fluid. Several other modalities, such as contrast-enhanced ultrasound (CEUS), magnetic resonance imaging (MRI), and near-infrared spectroscopy (NIRS), are also emerging. In this article, we have reviewed the available imaging options for NEC evaluation.

Feasibility and acceptability of a diagnostic randomized clinical trial of bowel ultrasound in infants with suspected necrotizing enterocolitis

We conducted a pilot diagnostic randomized clinical trial (RCT) to examine the feasibility, acceptability, and preliminary outcomes of adding bowel ultrasound (BUS) to the diagnostic evaluation for necrotizing enterocolitis (NEC). Infants ≤ 32 weeks' gestational age with NEC concern were randomized to undergo abdominal X-ray (AXR) or AXR + BUS. The primary outcome was study feasibility. Secondary outcomes included rates of NEC diagnosis and duration of treatment with bowel rest and antibiotics. A total of 56 infants were enrolled; 16 developed NEC concern and were randomized. Rates of recruitment (56/82 = 68%), retention (16/16 = 100%), and protocol compliance (126/127 = 99%) met pre-specified thresholds for feasibility. No significant differences in rates of NEC diagnosis were found between the two groups. Durations of bowel rest and antibiotic treatment were also similar.   Conclusion: Our study supports the feasibility of conducting a definitive diagnostic RCT to establish safety and efficacy of BUS for NEC.   Clinical trial registration: The study was registered at https://clinicaltrials.gov (NCT03963011). What is Known: • Bowel ultrasound (BUS) is increasingly being utilized as an adjunct to abdominal radiographs in evaluating for necrotizing enterocolitis (NEC). • The impact of BUS on patient outcomes is unknown. What is New: • A diagnostic randomized controlled trial study design to determine safety and effectiveness of adding BUS to NEC evaluation is feasible and acceptable.

Association of time of first corticosteroid treatment with bronchopulmonary dysplasia in preterm infants

OBJECTIVE

To evaluate the association between the time of first systemic corticosteroid initiation and bronchopulmonary dysplasia (BPD) in preterm infants.

STUDY DESIGN

A multi-center retrospective cohort study from January 2010 to December 2016 using the Children's Hospitals Neonatal Database and Pediatric Health Information System database was conducted. The study population included preterm infants <32 weeks' gestation treated with systemic corticosteroids after 7 days of age and before 34 weeks' postmenstrual age. Stepwise multivariable logistic regression was used to assess the association between timing of corticosteroid initiation and the development of Grade 2 or 3 BPD as defined by the 2019 Neonatal Research Network criteria.

RESULTS

We identified 598 corticosteroid-treated infants (median gestational age 25 weeks, median birth weight 760 g). Of these, 47% (280 of 598) were first treated at 8-21 days, 25% (148 of 598) were first treated at 22-35 days, 14% (86 of 598) were first treated at 36-49 days, and 14% (84 of 598) were first treated at >50 days. Infants first treated at 36-49 days (aOR 2.0, 95% CI 1.1-3.7) and >50 days (aOR 1.9, 95% CI 1.04-3.3) had higher independent odds of developing Grade 2 or 3 BPD when compared to infants treated at 8-21 days after adjusting for birth characteristics, admission characteristics, center, and co-morbidities.

CONCLUSIONS

Among preterm infants treated with systemic corticosteroids in routine clinical practice, later initiation of treatment was associated with a higher likelihood to develop Grade 2 or 3 BPD when compared to earlier treatment.

Dynamics of the preterm gut microbiome in health and disease

Advances in metagenomics have allowed a detailed study of the gut microbiome, and its role in human health and disease. Infants born prematurely possess a fragile gut microbial ecosystem that is vulnerable to perturbation. Alterations in the developing gut microbiome in preterm infants are linked to life-threatening diseases such as necrotizing enterocolitis (NEC) and late-onset sepsis; and may impact future risk of asthma, atopy, obesity, and psychosocial disease. In this mini-review, we summarize recent literature on the origins and patterns of development of the preterm gut microbiome in the perinatal period. The host-microbiome-environmental factors that portend development of dysbiotic intestinal microbial patterns associated with NEC and sepsis are reviewed. Strategies to manipulate the microbiome and mitigate dysbiosis, including the use of probiotics and prebiotics will also be discussed. Finally, we explore the challenges and future directions of gut microbiome research in preterm infants.

Racial Disparities in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a serious disease of the intestinal tract affecting 5-10% of pre-term infants with up to 50% mortality in those that require surgery. There is wide variation in the rates and outcomes of NEC by race and ethnicity, and the reasons for this disparity are poorly understood. In this article, we review the epidemiology and discuss possible explanations for racial and ethnic differences in NEC. Most of the current evidence investigating the role of race in NEC comes from North America and suggests that Hispanic ethnicity and non-Hispanic Black race are associated with higher risk of NEC compared to non-Hispanic White populations. Differences in pre-term births, breastfeeding rates, and various sociodemographic factors does not fully account for the observed disparities in NEC incidence and outcomes. While genetic studies are beginning to identify candidate genes that may increase or decrease risk for NEC among racial populations, current data remain limited by small sample sizes and lack of validation. Complex interactions between social and biological determinants likely underly the differences in NEC outcomes among racial groups. Larger datasets with detailed social, phenotypic, and genotypic information, coupled with advanced bioinformatics techniques are needed to comprehensively understand racial disparities in NEC.

Implementation of bowel ultrasound practice for the diagnosis and management of necrotising enterocolitis

Necrotising enterocolitis (NEC) is a serious inflammatory bowel disease of prematurity with potentially devastating complications and remains a leading cause of morbidity and mortality among premature infants. In recent years, there has been accumulating data regarding benefits of using bowel ultrasound (BUS) in the diagnosis and management of NEC. Despite this, adoption of robust BUS programmes into clinical practice has been slow. As BUS is a relatively new technique, many barriers to implementation exist, namely lack of education and training for sonographers and radiologists, low case volume and unfamiliarity by clinicians regarding how to use the information provided. The aim of this manuscript is to provide a framework and a roadmap for units to implement BUS in day-to-day practice for NEC diagnosis and management.

NEC-like intestinal injury is ameliorated by Lactobacillus rhamnosus GG in parallel with SIGIRR and A20 induction in neonatal mice

BACKGROUND

Exaggerated Toll-like receptor (TLR) signaling and intestinal dysbiosis are key contributors to necrotizing enterocolitis (NEC). Lactobacillus rhamnosus GG (LGG) decreases NEC in preterm infants, but underlying mechanisms of protection remain poorly understood. We hypothesized that LGG alleviates dysbiosis and upregulates TLR inhibitors to protect against TLR-mediated gut injury.

METHODS

Effects of LGG (low- and high-dose) on intestinal pro-inflammatory TLR signaling and injury in neonatal mice subjected to formula feeding (FF) and NEC were determined. 16S sequencing of stool and expression of anti-TLR mediators SIGIRR (single immunoglobulin interleukin-1-related receptor) and A20 were analyzed.

RESULTS

FF induced mild intestinal injury with increased expression of interleukin-1β (IL-1β) and Kupffer cell (KC) (mouse homolog of IL-8) compared to controls. LGG decreased IL-1β and KC in association with attenuated TLR signaling and increased SIGIRR and A20 expression in a dose-dependent manner. Low- and high-dose LGG had varying effects on gut microbiome despite both doses providing gut protection. Subsequent experiments of LGG on NEC revealed that pro-inflammatory TLR signaling and intestinal injury were also decreased, and SIGIRR and A20 expression increased, in a dose-dependent manner with LGG pre-treatment.

CONCLUSIONS

LGG protects against intestinal TLR-mediated injury by upregulating TLR inhibitors without major changes in gut microbiome composition.

Timing of postnatal corticosteroid treatment for bronchopulmonary dysplasia and its effect on outcomes

OBJECTIVE

To determine the association of timing of steroid therapy for bronchopulmonary dysplasia (BPD) and outcomes.

METHODS

Retrospective cohort study of preterm infants treated with low-dose dexamethasone for BPD. Infants treated with steroids at day of life (DOL) 14-28 (moderately late group) were compared to infants treated at DOL 29-42 (delayed group). Inverse probability of treatment weighting (IPTW) adjusted propensity scores were used to correct for potential confounders. The primary outcome of interest was postmenstrual age (PMA) at discharge.

RESULTS

Fifty-five infants (25 with moderately late treatment; 30 with delayed treatment) were identified. The mean age at treatment was 23 days in the moderately late group and 35 days in the delayed group. At time of treatment, infants treated moderately late were more likely to be on high frequency ventilation (96% vs 47%, P < 0.0001) and had higher fraction of inspired oxygen (70.7 ± 17.9% vs 56.2 ± 18.4%, P = 0.005) compared to infants treated later. Despite being the sicker group, moderately late treated infants were discharged at an earlier corrected age compared to infants with delayed treatment (PMA 42.9 ± 4.5 vs 47.5 ± 8.3 weeks, IPTW adjusted P = 0.03). Moderately late treatment was also associated with fewer days on mechanical ventilation (46.0 ± 19.0 days vs 77.4 ± 67.0 days, IPTW adjusted P = 0.02) and fewer days on supplemental oxygen (114.3 ± 40.8 days vs 149.8 ± 57.0 days, IPTW adjusted P = 0.005).

CONCLUSIONS

Among preterm infants at high risk of BPD, delaying treatment with postnatal steroids is associated with comparatively worse short-term outcomes as compared to earlier treatment.

Genetic predisposition to necrotizing enterocolitis in premature infants: Current knowledge, challenges, and future directions

The role of genetics in the pathogenesis of necrotizing enterocolitis (NEC) was initially informed by epidemiological data indicating differences in prevalence among different ethnic groups as well as concordance in twins. These early observations, together with major advances in genomic research, paved the way for studies that begin to reveal the contribution of genetics to NEC. Using the candidate gene or pathway approach, several potential pathogenic variants for NEC in premature infants have already been identified. More recently, genome-wide association studies and exome-sequencing based studies for NEC have been reported. These advances, however, are tempered by the lack of adequately powered replication cohorts to validate the accuracy of these discoveries. Despite many challenges, genetic research in NEC is expected to increase, providing new insights into its pathogenesis and bringing the promise of personalized care closer to reality. In this review we provide a summary of genetic studies in NEC along with defining the challenges and possible future approaches.

Outcomes of Infants Who Failed to Extubate despite Systemic Corticosteroids

Objective The objective of this study was to assess the outcomes of preterm infants who failed to extubate following initial treatment with steroids.

Materials and Methods This is a retrospective cohort study of ventilator-dependent preterm infants treated with first course of systemic steroids to facilitate extubation. Outcomes of infants who successfully extubated were compared with infants who failed to extubate.

Results In this study, 74 infants (mean gestation 25.4 ± 1.4 weeks and mean birth weight 764 ± 163 g) met inclusion criteria. Of these, 41 (55%) were successfully extubated and 33 (45%) were not. Baseline demographics were similar between the two groups. The primary outcome of severe bronchopulmonary dysplasia (BPD) or death at 36 weeks was higher among infants who failed to extubate (94 vs. 63%, p = 0.002). Severe BPD remained significantly higher even after adjustment for potential confounders (odds ratio: 12.2, 95% confidence interval: 2.1–70.5, p = 0.005). Extubation failure was also associated with substantially higher rate of tracheostomy (32 vs. 5%, p = 0.003) and gastrostomy tube placement (61 vs. 22%, p = 0.001), as well as longer days of hospitalization (179 ± 72 vs. 129 ± 44 days, p = 0.001) and mechanical ventilation (112 ± 89 vs. 52 ± 42 days, p < 0.001).

Conclusion Failure to extubate after first course of systemic steroids for BPD is associated with poor prognostic implications.

Neonatal Graves' Disease with Maternal Hypothyroidism

Neonatal Graves' disease presenting as conjugated hyperbilirubinemia is a diagnostic challenge because the differential includes a gamut of liver and systemic diseases. We present a unique case of neonatal Graves' disease in a premature infant with conjugated hyperbilirubinemia born to a mother with hypothyroidism during pregnancy and remote history of Graves' disease. Infant was treated with a combination of methimazole, propranolol, and potassium iodide for 4 weeks. Thyroid function improved after 8 weeks of treatment with full recovery of thyroid function, disappearance of thyroid-stimulating antibodies, and resolution of failure to thrive and conjugated hyperbilirubinemia. This case provides several clinical vignettes as it is a rare, severe, presentation of an uncommon neonatal disease, signs, symptoms, and clinical history presented a diagnostic challenge for neonatologists and endocrinologists, normal newborn screen was misleading, and yet timely treatment led to a full recovery.

A comparison of 7-day versus 10-day course of low-dose dexamethasone for chronically ventilated preterm infants

OBJECTIVE

The objective of the study was to compare the effect of two different dexamethasone regimens on respiratory outcomes of ventilator-dependent preterm infants.

STUDY DESIGN

Retrospective study of ventilated preterm infants <29 weeks gestational age treated with either 7-day or 10-day dexamethasone course. Primary outcome was days to successful extubation. Other outcomes included rate of successful extubation and need for repeat steroid therapy.

RESULTS

Fifty-nine infants were identified; 32 (54%) received 7 days of dexamethasone and 27 (46%) received 10 days of dexamethasone. Both groups had comparable baseline demographics and clinical characteristics. Mean time to successful extubation was similar between the two groups (5.1±2.7 days in 7-day group and 6.0±3.7 days in 10-day group, P=0.42). Successful extubation by end of treatment (56% versus 67%, P=0.44) and need for repeat steroid therapy (47% versus 33%, P=0.43) were also similar.

CONCLUSION

7-day and 10-day course of dexamethasone have comparable efficacy in facilitating extubation of ventilator-dependent preterm infants.

Genetic alterations in necrotizing enterocolitis

An underlying genetic predisposition to necrotizing enterocolitis (NEC) is increasingly being recognized. Candidate gene or pathway approaches as well as genome-wide approaches are beginning to identify potential pathogenic variants for NEC in premature infants. However, a majority of these studies have not yielded definitive results because of limited sample size and lack of validation. Despite these challenges, understanding the contribution of genetic variation to NEC is important for providing new insights into the pathogenesis of NEC as well as allowing for targeted care of infants with inherent susceptibility. In this review we provide a summary of published genetic association studies in NEC along with defining the challenges and possible future approaches.

Alterations in gene expression and DNA methylation during murine and human lung alveolar septation

DNA methylation, a major epigenetic mechanism, may regulate coordinated expression of multiple genes at specific time points during alveolar septation in lung development. The objective of this study was to identify genes regulated by methylation during normal septation in mice and during disordered septation in bronchopulmonary dysplasia. In mice, newborn lungs (preseptation) and adult lungs (postseptation) were evaluated by microarray analysis of gene expression and immunoprecipitation of methylated DNA followed by sequencing (MeDIP-Seq). In humans, microarray gene expression data were integrated with genome-wide DNA methylation data from bronchopulmonary dysplasia versus preterm and term lung. Genes with reciprocal changes in expression and methylation, suggesting regulation by DNA methylation, were identified. In mice, 95 genes with inverse correlation between expression and methylation during normal septation were identified. In addition to genes known to be important in lung development (Wnt signaling, Angpt2, Sox9, etc.) and its extracellular matrix (Tnc, Eln, etc.), genes involved with immune and antioxidant defense (Stat4, Sod3, Prdx6, etc.) were also observed. In humans, 23 genes were differentially methylated with reciprocal changes in expression in bronchopulmonary dysplasia compared with preterm or term lung. Genes of interest included those involved with detoxifying enzymes (Gstm3) and transforming growth factor-β signaling (bone morphogenetic protein 7 [Bmp7]). In terms of overlap, 20 genes and three pathways methylated during mouse lung development also demonstrated changes in methylation between preterm and term human lung. Changes in methylation correspond to altered expression of a number of genes associated with lung development, suggesting that DNA methylation of these genes may regulate normal and abnormal alveolar septation.

A randomised trial of re-feeding gastric residuals in preterm infants

OBJECTIVE

To determine whether re-feeding of gastric residual volumes reduces the time needed to achieve full enteral feeding in preterm infants.

DESIGN

Parallel-group randomised controlled trial with a 1:1 allocation ratio.

SETTING

Regional referral neonatal intensive care unit.

PATIENTS

72 infants of gestational age 23(0/7) to 28(6/7) weeks receiving minimal enteral nutrition (<24 mL/kg/day) during the first week after birth.

INTERVENTIONS

Infants were randomised to either be re-fed with gastric residual volumes (Re-feeding group) or receive fresh formula/human milk (Fresh-feeding group) whenever large gastric residual volumes were noted.

MAIN OUTCOME MEASURE

The primary efficacy end point was time to achieve full enteral feeding (≥120 mL/kg/day) after randomisation.

RESULTS

The mean time to full enteral feeding was 10.0 days in the Re-feeding group and 11.3 days in the Fresh-feeding group (mean difference favouring re-feeding: -1.3 days; 95% CI -2.9 to 0.3; p=0.11). The composite safety end point of spontaneous intestinal perforation, surgical necrotising enterocolitis, or death occurred in 6 of 36 infants (17%) in the Re-feeding group versus 10 of 36 infants (28%) in the Fresh-feeding group (p=0.26).

CONCLUSIONS

Re-feeding gastric residual volumes in extremely preterm infants does not reduce time to achieve full enteral feeding. This trial suggests that re-feeding might be as safe as fresh feeding, but further research is needed, due to lack of sufficient statistical power in this study for safety analysis.

TRIAL REGISTRATION NUMBER

NCT01420263NCT01420263.

B-type natriuretic peptide and mortality in extremely low birth weight infants with pulmonary hypertension: a retrospective cohort analysis

Background

B-type natriuretic peptide (BNP) is a strong predictor of mortality in adult patients with various forms of pulmonary hypertension (PH) and may be a strong prognostic marker in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) associated PH as well. We sought to assess the relationship between BNP levels and all-cause mortality in a cohort of ELBW infants with BPD and PH.

Methods

We retrospectively identified ELBW infants with BPD and PH who had serum BNP levels measured as part of routine clinical care in the neonatal intensive care unit. Peak serum BNP levels were correlated with survival to discharge or death.

Results

Thirty-six ELBW infants (mean gestational age 26.0 ± 1.9 weeks and mean birth weight 740 ± 290 grams) with BPD and PH had available survival data and had serum BNP levels measured. Peak BNP level was significantly lower among infants who survived than among those who died (128 pg/ml, [IQR 23 to 463] vs. 997 pg/ml, [IQR 278 to 1770], P < 0.004). On multivariate Cox proportional hazard analysis, BNP predicted survival independent of age, gender, and BPD severity. Area under receiver operator characteristic analysis identified a BNP value of 220 pg/ml to have 90% sensitivity and 65% specificity in predicting mortality.

Conclusion

BNP estimation may be useful as a prognostic marker of all-cause mortality in ELBW infants with BPD associated PH.

Clinical dilemma of positive histologic chorioamnionitis in term newborn

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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