Necrotizing enterocolitis: the search for a unifying pathogenic theory leading to prevention

PDA management strategies and pulmonary hypertension in extreme preterm infants with bronchopulmonary dysplasia

BACKGROUND

Premature infants are at risk for developing pulmonary hypertension (PH) in the context of bronchopulmonary dysplasia (BPD). Studies suggest a potential link between prolonged patent ductus arteriosus (PDA) exposure and BPD-PH, though management strategies remain controversial.

METHODS

Retrospective echocardiographic evaluation of newborns <29 weeks gestational age with BPD at two distinct centers. Primary objective was to evaluate the relationship between center-specific PDA management strategies (interventional or conservative) and the prevalence of BPD-PH. BPD was defined as oxygen or respiratory support at 36 weeks post-menstrual age (PMA). The presence of PH was defined as either an estimated sPAP of ≥40 mmHg or sEI ≥1.3. Center A has a conservative PDA policy. Center B has a targeted interventional policy.

RESULTS

PH rates were similar between sites (21% vs 17%), while rates of PDA treatment was different (7% vs 81). Adjusted models did not demonstrate an association for center or PDA treatment exposure for PH and EI, although infants from Center A had echocardiography evidence of higher systolic eccentricity index (EI; 1.12 ± 0.19 vs 1.06 ± 0.15, p = 0.04). Markers of RV function (TAPSE and RV-FAC) were similar between groups.

CONCLUSION

In preterm infants <29 weeks with BPD, conservative PDA treatment policy was not associated with higher rate of pulmonary hypertension diagnosis.

IMPACT

The association between PDA-management approaches and the occurrence of BPD-associated pulmonary vascular disease in premature infants has sparsely been described. We found that a conservative policy, regarding the PDA, was not associated with an increase in pulmonary hypertension diagnosis. We identified that, in patients with BPD, echocardiographic metrics of LV performance were lower.

Hyperbilirubinemia and retinopathy of prematurity: a retrospective cohort study

Retinopathy of prematurity (ROP) is a vasoproliferative retinal disease in preterm infants. Oxidative stress plays a key role in the pathogenesis of ROP. Due to its antioxidant effects, bilirubin has been proposed to be protective against ROP. This study explored the association between hyperbilirubinemia and ROP. We analyzed a 10-year cohort from a neonatal intensive care unit in Milan, Italy, including 1606 infants born under 32 weeks and/or < 1500 g. Data from 1606 infants meeting specific inclusion criteria were reviewed. Eighty infants were excluded due to lack of data, 1526 were deemed eligible for analysis, and 1269 had hyperbilirubinemia requiring phototherapy. There was a higher incidence of ROP among infants with hyperbilirubinemia (13.8%) versus those without (7.8%, p<0.01). Infants with any ROP, non-severe or severe ROP, were exposed to hyperbilirubinemia for a significantly higher number of days compared with those without ROP. Each additional day of exposure increases the risk of developing any ROP by 5%, non-severe ROP by 4%, and severe ROP by 6%. However, this correlation was not observed in infants with gestational age less than 27 weeks and/or body weight less than 1000 g.    Conclusion: Our data show that hyperbilirubinemia requiring phototherapy is associated with an increased risk of developing ROP. However, severe hyperbilirubinemia and ROP share many of their risk factors. Therefore, rather than being a risk factor itself, hyperbilirubinemia may be a surrogate for other risk factors for ROP.    Clinical Trial Registration: NCT05806684. What is Known: • The development of retinopathy of prematurity (ROP) is influenced by several critical risk factors, including low gestational age, low birth weight, supplemental oxygen use, and increased oxidative stress. • In vitro, unconjugated bilirubin is an effective scavenger of harmful oxygen species and a reducing agent, highlighting its potential protective role against oxidative stress. What is New: • Hyperbilirubinemia requiring phototherapy was associated with an increased risk of developing ROP, but this association was not observed in the most vulnerable population of extremely preterm infants. • Every additional day of phototherapy for hyperbilirubinemia increases the risk of ROP by 5% for any ROP, 4% for non-severe ROP, and 6% for severe ROP.

Fetal inflammatory response syndrome predicts early-onset sepsis and cystic periventricular leukomalacia in preterm neonates: A retrospective study

BACKGROUND

Fetal inflammatory response syndrome (FIRS), the fetal equivalent of chorioamnionitis, is associated with poorer neonatal outcomes. FIRS is diagnosed through placental histology, namely by the identification of funisitis (inflammation of the umbilical cord) and chorionic vasculitis (inflammation of fetal vessels within the chorionic plate). The aim of this study was to identify and evaluate associations between FIRS and neonatal outcomes in preterm neonates.

METHODS

We performed a retrospective cohort study at a level III neonatal intensive care unit (NICU), from January 1st 2008 to December 31st 2022, involving all inborn neonates with a gestational age below 30 weeks. We compared preterm neonates based on whether their placental histology described funisitis with chorionic vasculitis (FCV) or not.

RESULTS

The study included 113 preterms, 27 (23.9%) of those had FCV and 86 (76.1%) did not. After adjusting to gestational age, prolonged rupture of membranes and preeclampsia, FCV was independently associated with the development of early-onset sepsis (OR = 7.3, p = 0.021) and cystic periventricular leukomalacia (OR = 4.6, p = 0.004).

CONCLUSION

The authors identified an association between FIRS and the development of early-onset sepsis and cystic periventricular leukomalacia, highlighting the importance of early detection and management of this condition in order to improve long-term neonatal outcomes.

Single Ventricular Assist Device Care and Outcomes for Failed Stage I Palliation: A Single-Center Decade of Experience

Single ventricular assist device (SVAD) use before and after stage I palliation (S1P) is increasing with limited data on outcomes. To address this knowledge gap, we conducted a single-center retrospective review to assess pre- and post-SVAD clinical status, complications, and outcomes. We leveraged a granular, longitudinal, local database that captures end-organ support, procedural interventions, hematologic events, laboratory data, and antithrombotic strategy. We identified 25 patients between 2013 and 2023 implanted at median age of 53 days (interquartile range [IQR] = 16-130); 80% had systemic right ventricles and underwent S1P. Median SVAD days were 54 (IQR = 29-86), and 40% were implanted directly from ECMO. Compared to preimplant, there was a significant reduction in inotrope use ( p = 0.013) and improved weight gain ( p = 0.008) post-SVAD. Complications were frequent including bleeding (80%), stroke (40%), acute kidney injury (AKI) (40%), infection (36%), and unanticipated catheterization (56%). Patients with in-hospital mortality had significantly more bleeding complications ( p = 0.02) and were more likely to have had Blalock-Thomas-Taussig shunts pre-SVAD ( p = 0.028). Survival to 1 year postexplant was 40% and included three recovered and explanted patients. At 1 year posttransplant, all survivors have technology dependence or neurologic injury. This study highlights the clinical outcomes and ongoing support required for successful SVAD use in failed single-ventricle physiology before or after S1P.

Association of low hemoglobin at birth and neurodevelopmental outcomes in preterm neonates ≤28 weeks' gestation: a retrospective cohort study

OBJECTIVE

To compare neurodevelopmental outcomes at 18-24 months corrected age (CA) for preterm infants who had hemoglobin levels <120 g/l versus those with hemoglobin level ≥120 g/l at birth.

METHODS

We included infants of ≤28 weeks gestational age (GA) born between January 2009 and June 2018. The primary outcome was neurodevelopmental impairment (NDI) at 18-24 months. Multivariable logistic regression was applied to determine the association.

RESULTS

Of the 2351 eligible neonates, 351 (14.9%) had hemoglobin levels <120 g/L at birth. Of the 2113 surviving infants, 1534 (72.5%) underwent developmental follow-up at 18-24 months CA. There was no statistically significant difference in ND outcomes between the two groups. The composite outcome of death or NDI was significantly higher in the low hemoglobin group.

CONCLUSION

In preterm infants ≤28 weeks GA, initial hemoglobin <120 g/L at birth was not associated with neurodevelopmental impairment at 18-24 months CA among survivors.

Erythropoietin and retinopathy of prematurity: a retrospective cohort study in Japan, 2008-2018

BACKGROUND

Erythropoietin has an angiogenic effect on the retina and might increase the risk of retinopathy of prematurity (ROP).

METHODS

This retrospective cohort study included infants born at 22 to 27 weeks' gestation between 2008 and 2018 who were admitted to neonatal intensive care units (NICUs). We compared mortality and morbidities between infants who received erythropoietin and those who did not.

RESULTS

Among 18,955 livebirth infants, this study included 16,031 infants, among which 14,373 infants received erythropoietin. The risk of ROP requiring treatment was significantly higher in the erythropoietin group than in the control group (33% vs. 26%; aOR 1.50 [95% CI 1.28-1.76]). On the other hand, the erythropoietin group had lower risks of death and necrotizing enterocolitis.

CONCLUSIONS

This study with a large sample size found that erythropoietin use was associated with increased risk of ROP requiring treatment, while being associated with reductions in deaths and NEC.

Furosemide and Ductus Arteriosus Closure in Very-Low-Birth-Weight Preterm Infants: A Comprehensive Retrospective Study

Ductus arteriosus closure may be delayed in preterm infants, and prostaglandin, a vasodilator, can affect ductal patency. Furosemide can increase renal prostaglandin synthesis, so its net effect on patent ductus arteriosus (PDA) is uncertain. Our goal is to explore the relationship between furosemide and spontaneous ductal closure in very-low-birth-weight preterm infants. Our treatment for PDA involves fluid restriction initially and furosemide administration for hemodynamically significant PDA until closure is confirmed by the echocardiogram. We enrolled 105 infants from 1 January 2019 to 30 June 2022 and evaluated the impact of furosemide on ductal closure, including exposure duration and cumulative dose. There is no correlation between furosemide exposure and spontaneous ductal closure (p = 0.384). Furosemide exposure does not delay the postmenstrual age at which spontaneous ductal closure occurs (p = 0.558). The time for spontaneous ductal closure is positively associated with furosemide prescription days (coefficient value = 0.547, p = 0.026) and negatively with gestational age (coefficient value = -0.384, p = 0.062). The prescription of furosemide does not impact the probability or time duration of ductus arteriosus spontaneous closure. The cumulative dose of furosemide has minimal impact on ductal closure. The correlation between furosemide exposure duration and ductal patency duration is likely due to our treatment protocol, with gestational age being a significant factor.

Neonatal Necrotizing Enterocolitis: An Update on Pathophysiology, Treatment, and Prevention

Necrotizing enterocolitis (NEC) is a life-threatening disease predominantly affecting premature and very low birth weight infants resulting in inflammation and necrosis of the small bowel and colon and potentially leading to sepsis, peritonitis, perforation, and death. Numerous research efforts have been made to better understand, treat, and prevent NEC. This review explores a variety of factors involved in the pathogenesis of NEC (prematurity, low birth weight, lack of human breast milk exposure, alterations to the microbiota, maternal and environmental factors, and intestinal ischemia) and reports treatment modalities surrounding NEC, including pain medications and common antibiotic combinations, the rationale for these combinations, and recent antibiotic stewardship approaches surrounding NEC treatment. This review also highlights the effect of early antibiotic exposure, infections, proton pump inhibitors (PPIs), and H2 receptor antagonists on the microbiota and how these risk factors can increase the chances of NEC. Finally, modern prevention strategies including the use of human breast milk and standardized feeding regimens are discussed, as well as promising new preventative and treatment options for NEC including probiotics and stem cell therapy.

Effect of Maternal Preeclampsia on Cardiac Structure and Function in Very Low Birth Weight Infants

OBJECTIVE

 We aimed to determine whether exposure to severe maternal preeclampsia (PE) in very low birth weight (VLBW) infants is associated with hypertrophic cardiac changes and altered hemodynamics.

STUDY DESIGN

 Case-control study of VLBW infants born at Los Angeles General Medical Center from May 2015 to August 2023, who had an echocardiogram within the first 7 days of life. Cases were infants exposed to maternal PE and controls were infants not exposed to maternal PE matched by birth weight (BW) 1:1. Laboratory, placental pathology results, hemodynamic data and clinical outcomes were collected and compared between cases and control infants.

RESULTS

 A total of 43 cases matched by BW with control infants were studied. There were no significant anatomical cardiac changes by echocardiography between cases and control infants. Cases had significantly higher blood pressure within the first 72 hours of life and lower ejection fraction (EF), fractional shortening, and peak systolic flow velocity through their patent ductus arteriosus (PDA) within the first week of life. Cases were more likely to be smaller despite being born at a later gestational age (GA), as well as small for GA with placental weight less than 10th percentile compared to control infants.

CONCLUSION

 Our findings indicate that infants born to mothers with PE have higher systemic vascular resistance as evidenced by elevated blood pressure, and lower EF and shortening fraction and higher pulmonary vascular resistance as evidenced by lower peak flow velocity through the PDA. We did not observe hypertrophic cardiac changes in exposed infants. These findings should be considered in clinical decision-making during management of these infants.

KEY POINTS

· VLBW infants exposed to severe PE have higher rate of Small for gestational age and smaller placentas.. · VLBW infants exposed to severe PE have higher systemic vascular resistance during transitional period and lower EF and fractional shortening.. · VLBW infants exposed to severe PE have higher pulmonary vascular resistance..

Comparison of preoperative and intraoperative surgeon diagnosis and pathologic findings in spontaneous intestinal perforation vs necrotizing enterocolitis

OBJECTIVE

To investigate the accuracy of preoperative and intraoperative diagnosis via comparison to pathologic diagnosis in spontaneous intestinal perforation (SIP) vs. necrotizing enterocolitis (NEC).

STUDY DESIGN

A retrospective review of neonates <1500 g treated for pneumoperitoneum between 07/2004-09/2022 was conducted. Patients treated for NEC medically prior to diagnosis and those treated with drain only were excluded. Fleiss' Kappa analysis assessed agreement between all three diagnoses: preoperative, intraoperative, and pathologic.

RESULT

Overall, 125 patients were included with mean birthweight 834.2 g (SD:259.2) and mean gestational age 25.8 weeks (SD:2.2). Preoperative and intraoperative diagnoses agreed in 90.3%, intraoperative and pathologic agreed in 71.1%, and preoperative and pathologic agreed in 75.2% of patients. Fleiss' Kappa was 0.55 (95% CI:0.43,0.68), indicating moderate agreement between the three diagnoses.

CONCLUSION

Our study shows moderate agreement between preoperative, intraoperative, and pathologic diagnoses. Further studies investigating the clinical characteristics of SIP and NEC are needed to improve diagnostic accuracy and management.

Prediction of bronchopulmonary dysplasia in very preterm infants: competitive risk model nomogram

Objective

To develop predictive clinical models of bronchopulmonary dysplasia (BPD) through competing risk analysis.

Methods

Retrospective observational cohort study, including preterm newborns ≤32 weeks gestational age, conducted between January 1, 2013 and September 30, 2022 in a third-level Neonatal Intensive Care Unit in Spain. A prediction study was carried out using competing risk models, where the event of interest was BPD and the competing event was death. A multivariate competing risk model was developed separately for each postnatal day (days 1, 3, 7 and 14). Nomograms to predict BPD risk were developed from the coefficients of the final models and internally validated.

Results

A total of 306 patients were included in the study, of which 73 (23.9%) developed BPD and 29 (9.5%) died. On day 1, the model with the greatest predictive capacity was that including birth weight, days since rupture of membranes, and surfactant requirement (area under the receiver operating characteristic (ROC) curve (AUC), 0.896; 95% CI, 0.792-0.999). On day 3, the final predictive model was based on the variables birth weight, surfactant requirement, and Fraction of Inspired Oxygen (FiO2) (AUC, 0.891; 95% CI, 0.792-0.989).

Conclusions

Competing risk analysis allowed accurate prediction of BPD, avoiding the potential bias resulting from the exclusion of deceased newborns or the use of combined outcomes. The resulting models are based on clinical variables measured at bedside during the first 3 days of life, can be easily implemented in clinical practice, and can enable earlier identification of patients at high risk of BPD.

Antimicrobial Stewardship in Neonates with Necrotizing Enterocolitis: A Quality Improvement Initiative

BACKGROUND

Antibiotic overutilization in the neonatal intensive care unit (NICU) has many adverse effects, and necrotizing enterocolitis (NEC) is one of the most common indications for antibiotics in premature infants. Evidence for a preferred antibiotic regimen for NEC is lacking. This project aims to reduce piperacillin-tazobactam use and overall antibiotic duration in neonates with NEC through the implementation of an antibiotic stewardship pathway based on the modified Bell stage classification system.

METHODS

A multidisciplinary team consisting of neonatology, pharmacy, infectious disease, and surgery developed an antibiotic protocol for the management of NEC based on Bell stage. Recommendations included 48 h of ampicillin/gentamicin (AG) for stage I, 5-10 days of AG for stage II, the addition of metronidazole for stage IIIA, and 7-14 days of piperacillin-tazobactam (PT) for stage IIIB. We evaluated overall antibiotic and PT exposure, progression to surgical NEC, NEC recurrence, antibiotic resistance, bacteremia/fungemia, and mortality 1 year pre- and post-protocol implementation.

RESULTS

27 patients pre-intervention and 44 post-intervention were analyzed. Antibiotic exposure was reduced from a median 119.19 to 80.65 days of therapy (DOT) per 1000 patient days (p = 0.11). PT exposure decreased after protocol implementation (median 68.78 vs. 7.97 DOT per 1000 patient days, p = 0.002). There were no significant differences in morbidity or mortality outcomes.

CONCLUSIONS

Antibiotic stewardship strategies can be implemented in the NICU without compromising outcomes in patients with NEC. Bell stage stratification appears to be an effective method for antibiotic selection. Further studies are needed in a larger population to optimize regimens and ensure safety.

TYPE OF STUDY

Retrospective comparative study.

LEVEL OF EVIDENCE

Level III.

Diagnosing Hirschsprung Disease in Children Younger than 6 Months of Age: Insights in Incidence of Complications of Rectal Suction Biopsy and Other Final Diagnoses

BACKGROUND

 The gold standard for diagnosing Hirschsprung disease (HD) in patients younger than 6 months is pathological examination of rectal suction biopsy (RSB). The aim of this study was to gain insight into the following: (1) complications following RSB, (2) final diagnosis of patients referred for RSB, and (3) factors associated with HD.

METHODS

 Patients suspected of HD referred for RSB at our center were analyzed retrospectively. Severity of complications of RSB was assessed using Clavien-Dindo (CD) grading. Factors associated with HD were tested using multivariate logistic regression analysis.

RESULTS

 From 2000 to 2021, 371 patients underwent RSB because of infrequent defecation, at a median age of 44 days. Three patients developed ongoing rectal bleeding (0.8%) graded CD1. Most frequent final diagnoses were: HD (n = 151, 40.7%), functional constipation (n = 113, 31%), idiopathic meconium ileus (n = 11, 3%), and food intolerance (n = 11, 3%). Associated factors for HD were male sex (odds ratio [OR], 3.19; confidence interval [CI], 1.56-6.53), presence of syndrome (OR, 7.18; CI, 1.63-31.69), younger age at time of RSB (OR, 0.98; CI, 0.85-0.98), meconium passage for more than 48 hours (OR, 3.15; CI, 1.51-6.56), distended abdomen (OR, 2.09; CI, 1.07-4.07), bilious vomiting (OR, 6.39; CI, 3.28-12.47), and failure to thrive (OR, 8.46; CI, 2.11-34.02) (model R 2 = 0.566).

CONCLUSION

 RSB is a safe procedure with few and only minor complications. In the majority of patients referred for RSB under the age of 6 months, HD was found followed by a functional cause for the defecation problems. RSB should be obtained on a low threshold in all patients under the age of 6 months with the suspicion of HD.

Association of Gestational Age at Birth With Left Cardiac Dimensions at Near-Term Corrected Age Among Extremely Preterm Infants

BACKGROUND

Remodeling and altered ventricular geometry have been described in adults born preterm. Although they seem to have an adverse cardiac phenotype, the impact of various degrees of prematurity on cardiac development has been scarcely reported. In this study, we evaluated the impact of gestational age (GA) at birth on cardiac dimensions and function at near-term age among extremely preterm infants.

METHODS

This is a retrospective single-center cohort study of infants born at <29 weeks of GA between 2015 and 2019. Infants with available clinically acquired echocardiography between 34 and 43 weeks were included. Two groups were investigated: those born <26 weeks and those born ≥26 weeks. All measurements were done by an expert masked to clinical data using the raw images. The primary outcome was measurements of cardiac dimensions and function based on GA group. Secondary outcomes were the association between cardiac dimensions and postnatal steroid exposure and with increments of GA at birth.

RESULTS

A total of 205 infants were included (<26 weeks, n = 102; ≥26 weeks, n = 103). At time of echocardiography, weight (2.4 ± 0.5 vs 2.5 ± 0.5 kg, P = .86) and age (37.2 ± 1.6 vs 37.1 ± 1.9 weeks, P = .74) were similar between groups. There was no difference in metrics of right-sided dimensions and function. However, left-sided dimensions were decreased in infants born <26 weeks, including systolic left ventricle (LV) diameter (1.06 ± 0.20 cm vs 1.12 ± 0.18 cm, P = .02), diastolic LV length (2.85 ± 0.37 vs 3.02 ± 0.57 cm, P = .02), and estimated LV end-diastolic volume (5.36 ± 1.69 vs 6.01 ± 1.79 mL, P = .02).

CONCLUSIONS

In our cohort of very immature infants, birth at the extreme of prematurity was associated with smaller left cardiac dimensions around 36 weeks of corrected age. Future longitudinal prospective studies should evaluate further the impact of prematurity on LV development and performance and their long-term clinical impact.

Intestine and brain TLR-4 modulation following N-acetyl-cysteine treatment in NEC rodent model

Necrotizing enterocolitis (NEC) brain injury is mediated through Toll-like receptor 4 (TLR4) on the intestinal epithelium and brain microglia. Our aim was to determine whether postnatal and/or prenatal NAC can modify NEC associated intestinal and brain TLR4 expression and brain glutathione levels in a rat model of NEC. Newborn Sprague-Dawley rats were randomized into three groups: Control (n = 33); NEC (n = 32)-hypoxia and formula feeding; and NEC-NAC (n = 34)-received NAC (300 mg/kg IP) in addition to NEC conditions. Two additional groups included pups of dams treated once daily with NAC (300 mg/kg IV) for the last 3 days of pregnancy: NAC-NEC (n = 33) or NAC-NEC-NAC (n = 36) with additional postnatal NAC. Pups were sacrificed on the fifth day, and ileum and brains harvested for TLR-4 and glutathione protein levels. Brain and ileum TLR-4 protein levels were significantly increased in NEC offspring as compared to control (brain 2.5 ± 0.6 vs. 0.88 ± 0.12 U and ileum 0.24 ± 0.04 vs. 0.09 ± 0.01, p < 0.05). When NAC was administered only to dams (NAC-NEC) a significant decrease in TLR-4 levels was demonstrated in both offspring brain (1.53 ± 0.41 vs. 2.5 ± 0.6 U, p < 0.05) and ileum (0.12 ± 0.03 vs. 0.24 ± 0.04 U, p < 0.05) as compared to NEC. The same pattern was demonstrated when NAC was administered only or postnatally. The decrease in brain and ileum glutathione levels observed in NEC offspring was reversed with all NAC treatment groups. NAC reverses the increase in ileum and brain TLR-4 levels and the decrease in brain and ileum glutathione levels associated with NEC in a rat model, and thus may protect from NEC associated brain injury.

Enteral Feeding and Antibiotic Treatment Do Not Influence Increased Coefficient of Variation of Total Fecal Bile Acids in Necrotizing Enterocolitis

Introduction

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants. In animal models, the accumulation of ileal bile acids (BAs) is a crucial component of NEC pathophysiology. Recently, we showed that the coefficient of variation of total fecal BAs (CV-TBA) was elevated in infants who develop NEC compared to matched controls. However, neither the type of enteral nutrition nor antibiotic treatments-parameters that could potentially influence BA levels-were used to match pairs. Thus, we assessed the relationships between exposure to enteral feeding types and antibiotic treatments with NEC status and CV-TBA.

Materials and methods

Serial fecal samples were collected from 79 infants born with birth weight (BW) ≤1800 gm and estimated gestational age (EGA) ≤32 weeks; eighteen of these infants developed NEC. Total fecal BA levels (TBA) were determined using a commercially available enzyme cycling kit. Relationships between CV-TBA and dichotomous variables (NEC status, demographics, early exposure variables) were assessed by independent samples t-tests. Fisher's exact tests were used to assess relationships between NEC status and categorical variables.

Results

High values for CV-TBA levels perfectly predicted NEC status among infants in this study. However, feeding type and antibiotic usage did not drive this relationship.

Conclusions

As in previous studies, high values for the CV-TBA levels in the first weeks of life perfectly predicted NEC status among infants. Importantly, feeding type and antibiotic usage-previously identified risk factors for NEC-did not drive this relationship.

A Retrospective Case Control Study Examining Procalcitonin as a Biomarker for Necrotizing Enterocolitis

Abstract Background: Procalcitonin (PCT) is a biomarker for sepsis, but its utility has not been investigated in necrotizing enterocolitis (NEC). Necrotizing enterocolitis is a devastating multisystem disease of infants that in severe cases requires surgical intervention. We hypothesize that an elevated PCT will be associated with surgical NEC. Patients and Methods: After obtaining Institutional Review Board (IRB) approval (#12655), we performed a single institution retrospective case control study between 2010 and 2021 of infants up to three months of age. Inclusion criteria was PCT drawn within 72 hours of NEC or sepsis diagnosis. Control infants had a PCT drawn in the absence of infectious symptoms. Recursive partitioning (RP) identified PCT cutoffs. Categorical variable associations were tested using Fisher exact or χ² tests. Continuous variables were tested using Wilcoxon rank sum test, Student t-test, and Kruskal-Wallis test. Adjusted associations of PCT and other covariables with NEC or sepsis versus controls were obtained via multinomial logistic regression analysis. Results: We identified 49 patients with NEC, 71 with sepsis, and 523 control patients. Based on RP, we selected two PCT cutoffs: 1.4 ng/mL and 3.19 ng/ml. A PCT of ≥1.4 ng/mL was associated with surgical (n = 16) compared with medical (n = 33) NEC (87.5% vs. 39.4%; p = 0.0015). A PCT of ≥1.4 ng/mL was associated with NEC versus control (p < 0.0001) even when adjusting for prematurity and excluding stage IA/IB NEC (odds ratio [OR], 28.46; 95% confidence interval [CI], 11.27-71.88). A PCT of 1.4-3.19 ng/mL was associated with both NEC (adjusted odds ratio [aOR], 11.43; 95% CI, 2.57-50.78) and sepsis (aOR, 6.63; 95% CI, 2.66-16.55) compared with controls. Conclusions: A PCT of ≥1.4 ng/mL is associated with surgical NEC and may be a potential indicator for risk of disease progression.

Expectant Management or Early Ibuprofen for Patent Ductus Arteriosus

BACKGROUND

Cyclooxygenase inhibitors are commonly used in infants with patent ductus arteriosus (PDA), but the benefit of these drugs is uncertain.

METHODS

In this multicenter, noninferiority trial, we randomly assigned infants with echocardiographically confirmed PDA (diameter, >1.5 mm, with left-to-right shunting) who were extremely preterm (<28 weeks' gestational age) to receive either expectant management or early ibuprofen treatment. The composite primary outcome included necrotizing enterocolitis (Bell's stage IIa or higher), moderate to severe bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. The noninferiority of expectant management as compared with early ibuprofen treatment was defined as an absolute risk difference with an upper boundary of the one-sided 95% confidence interval of less than 10 percentage points.

RESULTS

A total of 273 infants underwent randomization. The median gestational age was 26 weeks, and the median birth weight was 845 g. A primary-outcome event occurred in 63 of 136 infants (46.3%) in the expectant-management group and in 87 of 137 (63.5%) in the early-ibuprofen group (absolute risk difference, -17.2 percentage points; upper boundary of the one-sided 95% confidence interval [CI], -7.4; P<0.001 for noninferiority). Necrotizing enterocolitis occurred in 24 of 136 infants (17.6%) in the expectant-management group and in 21 of 137 (15.3%) in the early-ibuprofen group (absolute risk difference, 2.3 percentage points; two-sided 95% CI, -6.5 to 11.1); bronchopulmonary dysplasia occurred in 39 of 117 infants (33.3%) and in 57 of 112 (50.9%), respectively (absolute risk difference, -17.6 percentage points; two-sided 95% CI, -30.2 to -5.0). Death occurred in 19 of 136 infants (14.0%) and in 25 of 137 (18.2%), respectively (absolute risk difference, -4.3 percentage points; two-sided 95% CI, -13.0 to 4.4). Rates of other adverse outcomes were similar in the two groups.

CONCLUSIONS

Expectant management for PDA in extremely premature infants was noninferior to early ibuprofen treatment with respect to necrotizing enterocolitis, bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. (Funded by the Netherlands Organization for Health Research and Development and the Belgian Health Care Knowledge Center; BeNeDuctus ClinicalTrials.gov number, NCT02884219; EudraCT number, 2017-001376-28.).

Outcomes in preterm infants who received a lipid emulsion with fish oil: An observational study

BACKGROUND

100% soybean oil emulsions (SO100) are associated with poor docosahexaenoic acid (DHA) and arachidonic acid (ARA) status in extremely low birth weight (ELBW) infants. A multi-oil emulsion with 15% fish oil (FO15) contains more DHA and ARA than SO100. This study compares clinical outcomes, namely growth and fatty acids, in ELBW infants who received S0100 or FO15.

METHODS

This observational study included ELBW infants born between 2014 and 2019 who received SO100 or FO15 for >7 days. Gas chromatography/mass spectrometry was used to measure erythrocyte fatty acids.

RESULTS

The mean ± SD gestational age was 27 ± 3 and 26 ± 2 weeks for SO100 (n = 43) and FO15 (n = 43), respectively (P = 0.2). DHA (-0.3 ± 0.10% per week, P = 0.026, for FO15 vs -0.2 ± 0.05% per week, P < 0.001, for SO100) and ARA (-0.8 ± 0.21% per week for FO15 vs -0.9 ± 0.17% per week for SO100; P < 0.001 for both) declined in both groups with no difference between groups (P interaction > 0.7 for both). After controlling for days to reach full feeds, the mean difference in weight z score trajectories was similar (Est = -0.08; 95% CI, -0.82 to 0.04; P = 0.2), and SO100 was associated with a nonsignificant increased odds for cholestasis (odds ratio, 3.1; 95% CI, 0.96-10.2; P = 0.059). There was no difference in other clinical comorbidities.

CONCLUSIONS

In comparison with ELBW infants who received SO100, infants who received FO15 still demonstrated a decline in DHA and ARA. Growth and other clinical outcomes were unchanged.

Thrombocytopenia and neonatal outcomes among extremely premature infants exposed to maternal hypertension

BACKGROUND

Hypertensive disorders of pregnancy (HDP) are associated with neonatal hematological disturbances, such as thrombocytopenia. The association of HDP to platelet counts in the context of extreme prematurity, to trends of platelet counts during neonatal hospitalization, and to frequency of platelet transfusions remain to be explored.

PROCEDURE

Retrospective study of infants born at less than 29 weeks born between 2015 and 2019. Platelet counts were collected on initial complete blood count, at 2 weeks, 32 weeks post-menstrual age (PMA), 36 weeks PMA, and closest to discharge. We examined the association between HDP and platelet counts at each time point, frequency of platelet transfusions and intraventricular hemorrhage (IVH) grade 3 or more.

RESULTS

Total 296 infants were included, 43 exposed to HDP. Infants exposed had lower platelet counts at each time point, as well as a higher prevalence of platelet less than 150 × 10⁹ /L on one of the time points (32% vs. 65%, p < .001). Infants exposed to maternal hypertension were more frequently exposed to platelet transfusions (63% vs. 18%, p < .001). Mixed effect model demonstrated an association between HDP and a lower trend in platelet counts at each time point (β = -94 × 10³ /μl, p < .001). Although initial platelet count was associated with severe IVH, it was not associated to exposure to HDP.

CONCLUSION

Premature infants exposed to HDP have a higher prevalence of thrombocytopenia, increased frequency of platelet transfusion, and an altered trend in platelet counts during neonatal hospitalization.

Acute Kidney Injury in Very Low Birth Weight Infants: A Major Morbidity and Mortality Risk Factor

BACKGROUND AND OBJECTIVES

Very low birth weight (VLBW) infants are at high risk of developing acute kidney injury (AKI), presumably secondary to low kidney reserves, stressful postnatal events, and drug exposures. Our study aimed to identify the prevalence, risk factors, and outcomes associated with AKI in VLBW infants.

STUDY DESIGN

Records of all VLBW infants admitted to two medical campuses between January 2019 and June 2020 were retrospectively reviewed. AKI was classified using the modified KDIGO definition to include only serum creatinine. Risk factors and composite outcomes were compared between infants with and without AKI. We evaluated the main predictors of AKI and death with forward stepwise regression analysis.

RESULTS

152 VLBW infants were enrolled. 21% of them developed AKI. Based on the multivariable analysis, the most significant predictors of AKI were the use of vasopressors, patent ductus arteriosus, and bloodstream infection. AKI had a strong and independent association with neonatal mortality.

CONCLUSIONS

AKI is common in VLBW infants and is a significant risk factor for mortality. Efforts to prevent AKI are necessary to prevent its harmful effects.

Risk Factors of Language Delay at Two Years of Corrected Age among Very-Low-Birth-Weight Preterm Infants: A Population-Based Study

Language delays are often underestimated in very-low-birth-weight (VLBW) preterm infants. We aimed to identify the risk factors of language delay at two years of corrected age in this vulnerable population. VLBW infants, who were assessed at two years of corrected age using the Bayley Scale of Infant Development, third edition, were included using a population-based cohort database. Language delay was defined as mild to moderate if the composite score was between 70 and 85 and severe if the score was < 70. Multivariable logistic regression analysis was used to identify the perinatal risk factors associated with language delay. The study comprised 3797 VLBW preterm infants; 678 (18%) had a mild to moderate delay and 235 (6%) had a severe delay. After adjusting for confounding factors, low maternal education level, low maternal socioeconomic status, extremely low birth weight, male sex, and severe intraventricular hemorrhage (IVH) and/or cystic periventricular leukomalacia (PVL) were found to be significantly associated with both mild to moderate and severe delays. Resuscitation at delivery, necrotizing enterocolitis, and patent ductus arteriosus requiring ligation showed significant associations with severe delay. The strongest factors predicting both mild to moderate and severe language delays were the male sex and severe IVH and/or cystic PVL; thus, early targeted intervention is warranted in these populations.

Supplementation of mother's own milk with term versus preterm donor human milk: a randomized controlled trial

The purpose of this is to evaluate the effect of supplementation of enteral feed volume with preterm versus term donor human milk (DHM) on short-term physical growth in very low birth weight (VLBW) neonates. In this open-label, variable block-sized, superiority, randomized controlled trial with allocation concealment, VLBW neonates with insufficient volume of mother's own milk (MOM) were assigned to receive either preterm (n = 48) or term (n = 54) DHM till discharge. Preterm DHM was defined as the breast milk expressed within 28 days of delivery at ≤ 34 weeks of gestation. The primary outcome was days to regain birth weight. Maternal and neonatal demographic variables were comparable in the two study groups. Days to regain birth weight were significantly more in the preterm DHM group, 17.4 (7.7) vs 13.6 (7.2) days, mean difference (95% CI) being 3.74 (0.48-7.0) days, P = 0.02). The proportion of MOM use was 82% in preterm vs 91.1%, P = 0.03 in the term milk group. Duration of skin-to-skin contact was also significantly lower in the preterm vs term milk group, the median (IQR) was 4 (0, 6) vs 4 (2, 6) hours/day, P < 0.01. However, bronchopulmonary dysplasia was higher in the preterm milk group (13% vs. 4%, P = 0.17). The velocity of gain in weight was similar in the two groups from week 1-3 but higher in the term DHM supplementation group during the 4th week. Conclusion: Supplementing MOM with preterm DHM did not result in a faster regaining of birth weight. Trial registration: CTRI/2020/02/023569; Date: 17.02.2020.

A quality improvement initiative to reduce necrotizing enterocolitis in high-risk neonates

OBJECTIVE

Prompted by an acute increase in necrotizing enterocolitis (NEC) rates, we aimed to decrease the rate of stage 2 or greater NEC in infants born at <1500 grams or <30 weeks gestational age from 19.5% to less than 9.7% (a 50% reduction) within 18 months, without adversely affecting central line-associated bloodstream infection (CLABSI) rates.

STUDY DESIGN

We utilized Define, Measure, Analyze, Improve, and Control (DMAIC) as our improvement model. Informed by our key driver diagram and root cause analyses, six Plan-Do-Study-Act cycles were completed.

RESULTS

147 infants in the QI initiative had a median gestational age of 28.1 weeks and a median birthweight of 1070 grams. NEC rates decreased from the QI baseline of 19.5% to 6% (p = 0.03). Oral care administration increased, and maximal gavage tube dwell time decreased.

CONCLUSION

NEC rates decreased during this QI initiative through a combination of multidisciplinary interventions aimed at reducing dysbiosis.

A Randomized Trial of an Exclusive Human Milk Diet in Neonates with Single Ventricle Physiology

OBJECTIVE

To determine whether weight gain velocity (g/kg/day) 30 days after the initiation of feeds after cardiac surgery and other clinical outcomes improve in infants with single ventricle physiology fed an exclusive human milk diet compared with a mixed human and bovine diet.

STUDY DESIGN

In this multicenter, randomized, single blinded, controlled trial, term neonates 7 days of age or younger with single ventricle physiology and anticipated cardiac surgical palliation within 30 days of birth were enrolled at 10 US centers. Both groups received human milk if fed preoperatively. During the 30 days after feeds were started postoperatively, infants in the intervention group received human milk fortified once enteral intake reached 60 mL/kg/day with a human milk-based fortifier designed for term neonates. The control group received standard fortification with formula once enteral intake reached 100 mL/kg/day. Perioperative feeding and parenteral nutrition study algorithms were followed.

RESULTS

We enrolled 107 neonates (exclusive human milk = 55, control = 52). Baseline demographics and characteristics were similar between the groups. The median weight gain velocity at study completion was higher in exclusive human milk vs control group (12 g/day [IQR, 5-18 g/day] vs 8 g/day [IQR, 0.4-14 g/day], respectively; P = .03). Other growth measures were similar between groups. Necrotizing enterocolitis of all Bell stages was higher in the control group (15.4 % vs 3.6%, respectively; P = .04). The incidence of other major morbidities, surgical complications, length of hospital stay, and hospital mortality were similar between the groups.

CONCLUSIONS

Neonates with single ventricle physiology have improved short-term growth and decreased risk of NEC when receiving an exclusive human milk diet after stage 1 surgical palliation.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov (www.

CLINICALTRIALS

gov, Trial ID: NCT02860702).

Thresholds for surfactant use in preterm neonates: a network meta-analysis

OBJECTIVE

To perform a network meta-analysis of randomised controlled trials of different surfactant treatment strategies for respiratory distress syndrome (RDS) to assess if a certain fraction of inspired oxygen (FiO₂) is optimal for selective surfactant therapy.

DESIGN

Systematic review and network meta-analysis using Bayesian analysis of randomised trials of prophylactic versus selective surfactant for RDS.

SETTING

Cochrane Central Register of Controlled Trials, MEDLINE, Embase and Science Citation Index Expanded.

PATIENTS

Randomised trials including infants under 32 weeks of gestational age.

INTERVENTIONS

Intratracheal surfactant, irrespective of type or dose.

MAIN OUTCOME MEASURES

Our primary outcome was neonatal mortality, compared between groups treated with selective surfactant therapy at different thresholds of FiO₂. Secondary outcomes included respiratory morbidity and major complications of prematurity.

RESULTS

Of 4643 identified references, 14 studies involving 5298 participants were included. We found no statistically significant differences between 30%, 40% and 50% FiO₂ thresholds. A sensitivity analysis of infants treated in the era of high antenatal steroid use and nasal continuous positive airway pressure as initial mode of respiratory support showed no difference in mortality, RDS or intraventricular haemorrhage alone but suggested an increase in the combined outcome of major morbidities in the 60% threshold.

CONCLUSION

Our results do not show a clear benefit of surfactant treatment at any threshold of FiO₂. The 60% threshold was suggestive of increased morbidity. There was no advantage seen with prophylactic treatment. Randomised trials of different thresholds for surfactant delivery are urgently needed to guide clinicians and provide robust evidence.

PROSPERO REGISTRATION NUMBER

CRD42020166620.

The effect of individualized iron supplementation on iron status in Dutch preterm infants born between 32 and 35 weeks of gestational age: evaluation of a local guideline

OBJECTIVE

Iron deficiency (ID) and iron deficiency anemia (IDA) in early life are associated with adverse effects. Preterm infants are at risk for developing ID(A). Considering that not every preterm infant develops ID(A) and the potential risk of iron overload, indiscriminate iron supplementation in late preterm infants is debatable. This study aimed to evaluate the effect of a locally implemented guideline regarding individualized iron supplementation on the prevalence of ID(A) at the postnatal age of 4-6 months in Dutch preterm infants born between 32 and 35 weeks of gestational age (GA).

METHODS

An observational study comparing the prevalence of ID(A) at the postnatal age of 4-6 months in Dutch preterm infants born between 32 and 35 weeks of GA before (i.e. PRE-guideline group) and after (i.e. POST-guideline group) implementation of the local guideline.

RESULTS

Out of 372 eligible preterm infants, 110 were included (i.e. 72 and 38 in the PRE- and POST-guideline group, respectively). ID- and IDA-prevalence rates at 4-6 months of age in the PRE-guideline group were 36.1% and 13.9%, respectively, and in the POST-guideline group, 21.1% and 7.9%, respectively, resulting in a significant decrease in ID-prevalence of 15% and IDA-prevalence of 6%. No indication of iron overload was found.

CONCLUSION

An individualized iron supplementation guideline for preterm infants born between 32 and 35 weeks GA reduces ID(A) at the postnatal age of 4-6 months without indication of iron overload.

Necrotizing Enterocolitis in a Term Newborn: A Case Report

This case report describes a 5-day-old term infant with necrotizing enterocolitis (NEC). The clinical presentation, diagnostic reasoning, current literature, hospital course, and follow-up are discussed. Necrotizing enterocolitis is a gastrointestinal emergency characterized by severe inflammation and ischemic necrosis of the intestinal mucosa. Usually a condition of prematurity, NEC primarily occurs in very low birth weight premature infants. Necrotizing enterocolitis can be managed medically or surgically, depending on the severity. Although the etiology of NEC is unknown, the clinical presentation includes abdominal distention and tenderness, feeding intolerance, grossly bloody stools, and severe hypotension and acidosis.

Early-Onset Neonatal Sepsis in Turkey: A Single-Center 7-Year Experience in Etiology and Antibiotic Susceptibility

BACKGROUND

The pathogen distribution and antibiotic susceptibility of the pathogens in early-onset sepsis (EOS) differ between countries. The epidemiological data from a limited number of studies about EOS in Turkey are insufficient. In this study, we aimed to evaluate the culture-proven EOS cases, causative microorganisms, antibiotic susceptibility patterns, and risk factors for mortality in EOS.

METHODS

This is a retrospective, single-center study over a 7-year period, from 2013 to 2020, at Zeynep Kamil Maternity and Children's Hospital, İstanbul, Turkey.

RESULTS

During the study period, 8229 newborns were admitted to our neonatal intensive care unit. Culture-proven EOS was detected in 101 patients (0.12%). Out of these, 56 (55.4%) were Gram-positive, and 45 (44.5%) were Gram-negative sepsis. The most common isolated organism was E. coli (28.7%, n = 29), followed by GBS (16.8%, n = 17) and S. aureus (15.8%, n = 16). An ampicillin and gentamicin combination had antimicrobial coverage in 92.6% of cases. Seventeen patients (16.8%) died because of EOS. Severe neutropenia was found to be an independent risk factor for mortality in EOS (p = 0.001, OR = 14.4, CI 95%: 2.8-74).

CONCLUSIONS

Although the majority of causative agents were Gram-positive (55.4%), the most common isolated organism was E. coli. An empirical antibiotic regimen of ampicillin and gentamicin continues to have an adequate coverage for EOS in our population.

Evaluation of the Association of Platelet Count, Mean Platelet Volume, and Platelet Transfusion With Intraventricular Hemorrhage and Death Among Preterm Infants

IMPORTANCE

Platelet transfusion is commonly performed in infants to correct severe thrombocytopenia or prevent bleeding. Exploring the associations of platelet transfusion, platelet count (PC), and mean platelet volume (MPV) with intraventricular hemorrhage (IVH) and in-hospital mortality in preterm infants can provide evidence for the establishment of future practices.

OBJECTIVES

To evaluate the associations of platelet transfusion, PC, and MPV with IVH and in-hospital mortality and to explore whether platelet transfusion-associated IVH and mortality risks vary with PC and MPV levels at the time of transfusion.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included preterm infants who were transferred to the neonatal intensive care unit on their day of birth and received ventilation during their hospital stay. The study was conducted at a neonatal intensive care unit referral center in Beijing, China, between May 2016 and October 2017. Data were retrieved and analyzed from December 2020 to January 2022.

EXPOSURES

Platelet transfusion, PC, and MPV.

MAIN OUTCOMES AND MEASURES

Any grade IVH, severe IVH (grade 3 or 4), and in-hospital mortality.

RESULTS

Among the 1221 preterm infants (731 [59.9%] male; median [IQR] gestational age, 31.0 [29.0-33.0] weeks), 94 (7.7%) received 166 platelet transfusions. After adjustment for potential confounders, platelet transfusion was significantly associated with mortality (hazard ratio [HR], 1.48; 95% CI, 1.13-1.93; P = .004). A decreased PC was significantly associated with any grade IVH (HR per 50 × 103/μL, 1.13; 95% CI, 1.05-1.22; P = .001), severe IVH (HR per 50 × 103/μL, 1.16; 95% CI, 1.02-1.32; P = .02), and mortality (HR per 50 × 103/μL, 1.74; 95% CI, 1.48-2.03; P < .001). A higher MPV was associated with a lower risk of mortality (HR, 0.83; 95% CI, 0.69-0.98; P = .03). The platelet transfusion-associated risks for both IVH and mortality increased when transfusion was performed in infants with a higher PC level (eg, PC of 25 × 103/μL: HR, 1.20; 95% CI, 0.89-1.62; PC of 100 × 103/μL: HR, 1.40; 95% CI, 1.08-1.82). The platelet transfusion-associated risks of IVH and mortality varied with MPV level at the time of transfusion.

CONCLUSIONS AND RELEVANCE

In preterm infants, platelet transfusion, PC, and MPV were associated with mortality, and PC was also associated with any grade IVH and severe IVH. The findings suggest that a lower platelet transfusion threshold is preferred; however, the risk of a decreased PC should not be ignored.

Peripheral and intestinal mucosal-associated invariant T cells in premature infants with necrotizing enterocolitis

Background: Necrotizing enterocolitis (NEC) is a potentially fatal inflammatory gastrointestinal disease in preterm infants with unknown pathogenesis. Mucosal-associated invariant T (MAIT) cells primarily accumulate at sites where exposure to microbes is ubiquitous and regulate immunological responses. As the implications of these cells in NEC development in premature infants remain unknown, we investigated the role and characteristics of MAIT cells in NEC pathogenesis.

Methods: The percentage of different MAIT cell subsets in peripheral blood samples of 30 preterm infants with NEC and 22 control subjects was estimated using flow cytometry. The frequency of MAIT cells in the intestinal tissues of five NEC patients and five control subjects was also examined. The level of serum cytokines was estimated using cytometric bead array. Potential associations between the different measurements were analyzed using the Spearman’s correlation test.

Results: Compared with controls, the NEC patients were found to have significantly reduced percentages of circulating CD161⁺ CD3⁺ CD8αα⁺ T cells and CD161⁺ CD3⁺ TCRγδ^-TCRVa7.2⁺ MAIT cells. In the intestinal tissues, the percentage of MAIT cells was significantly higher in samples from the NEC patients than the controls. Furthermore, the percentage of circulating MAIT cells in the peripheral blood samples was inversely correlated with that in the intestinal tissues of the NEC patients. The percentage of CD8αα⁺ MAIT cells was found to be significantly reduced in both peripheral blood and intestinal tissues of NEC patients. Following treatment, the frequency of circulating MAIT cells significantly increased in NEC patients and reached a level similar to that in the control subjects. However, there was no difference in the percentage of circulating CD8αα⁺ MAIT cells before and after treatment in the NEC patients.

Conclusion: Our results suggested that during the development of NEC MAIT cells accumulate in the inflammatory intestinal tissues, while the percentage of CD8aa⁺ MAIT cells is significantly decreased, which may lead to the dysfunction of MAIT cells in gut immunity.

Natural evolution of the patent ductus arteriosus in the extremely premature newborn and respiratory outcomes

OBJECTIVE

Evaluate spontaneous closure of the patent ductus arteriosus (PDA) in extremely preterm infants and their respiratory outcomes, especially at <26 weeks gestational age (GA).

STUDY DESIGN

Retrospective study in <29 weeks, admitted within 24 h after birth (Feb 2015 and Dec 2019). Infants without any intervention to promote ductal closure, ≥1 echocardiography, and alive at discharge were included.

RESULTS

Two hundred and fourteen infants (average GA 26.3 ± 1.5 weeks) were included; 84 (39%) <26 weeks. PDA closed spontaneously in 194 (91%); 76/84 (90%) for infants <26 weeks. PDA closure was ascertained on an echocardiography performed at a median age of 36.4 [34.4-40.1] weeks. Rate of moderate-to-severe bronchopulmonary dysplasia decreased throughout the study period (OR for year of birth: 0.70 [95% CI: 0.57-0.87], p = 0.001).

CONCLUSION

Majority of extremely preterm infants, including <26 weeks, had spontaneous closure of the ductus before term corrected age. There was a concomitant improvement of respiratory outcomes.

Reduction of Severe Intraventricular Hemorrhage in Preterm Infants: A Quality Improvement Project

OBJECTIVES

The aim of this quality improvement project was to reduce the rate of severe intraventricular hemorrhage (sIVH) by 50% within 3 years for extremely preterm infants born at a children's teaching hospital.

METHODS

A multidisciplinary team developed key drivers for the development of intraventricular hemorrhage in preterm infants. Targeted interventions included the development of potentially better practice guidelines, promoting early noninvasive ventilation, consistent use of rescue antenatal betamethasone, and risk-based indomethacin prophylaxis. The outcome measure was the rate of sIVH. Process measures included the rate of intubation within 24 hours and receipt of rescue betamethasone and risk-based indomethacin prophylaxis. Common markers of morbidity were balancing measures. Data were collected from a quarterly chart review and analyzed with statistical process control charts. The preintervention period was from January 2012 to March 2016, implementation period was from April 2016 to December 2018, and sustainment period was through June 2020.

RESULTS

During the study period, there were 268 inborn neonates born at <28 weeks' gestation or <1000 g (127 preintervention and 141 postintervention). The rate of sIVH decreased from 14% to 1.2%, with sustained improvement over 2 and a half years. Mortality also decreased by 50% during the same time period. This was associated with adherence to process measures and no change in balancing measures.

CONCLUSIONS

A multipronged quality improvement approach to intraventricular hemorrhage prevention, including evidence-based practice guidelines, consistent receipt of rescue betamethasone and indomethacin prophylaxis, and decreasing early intubation was associated with a sustained reduction in sIVH in extremely preterm infants.

Randomized Controlled Trial of Two Timepoints for Introduction of Standardized Complementary Food in Preterm Infants

In term infants it is recommended to introduce solids between the 17th and 26th week of life, whereas data for preterm infants are missing. In a prospective, two-arm interventional study we investigated longitudinal growth of VLBW infants after early (10-12th) or late (16-18th) week of life, corrected for term, introduction of standardized complementary food. Primary endpoint was height at one year of age, corrected for term, and secondary endpoints were other anthropometric parameters such as weight, head circumference, BMI, and z-scores. Among 177 infants who underwent randomization, the primary outcome could be assessed in 83 (93%) assigned to the early and 83 (94%) to the late group. Mean birthweight was 941 (SD ± 253) g in the early and 932 (SD ± 256) g in the late group, mean gestational age at birth was 27 + 1/7 weeks in both groups. Height was 74.7 (mean; SD ± 2.7) cm in the early and 74.4 cm (mean; SD ± 2.8; n.s.) cm in the late group at one year of age, corrected for term. There were no differences in anthropometric parameters between the study groups except for a transient effect on weight z-score at 6 months. In preterm infants, starting solids should rather be related to neurological ability than to considerations of nutritional intake and growth.

Early versus late-onset necrotizing enterocolitis in very low birth infants in the neonatal intensive care unit

BACKGROUND

Necrotizing enterocolitis (NEC), one of the most severe emergencies in neonates, is a multifactorial disease with diverse risk factors.

OBJECTIVES

To compare between the clinical and laboratory characteristics of premature infants diagnosed with early-onset NEC (EO-NEC) and those with late-onset NEC (LO-NEC).

PATIENTS AND METHODS

Enrolled infants were identified from prospective local data collected for the Israel National very low birth weight (VLBW, < 1500 g) infant database and from the local electronic patient files data base for the period 1996-2017.

RESULTS

Overall, 95 VLBW infants (61, 64.21% EO-NEC and 34, 35.87% LO-NEC) were enrolled. EO-NEC infants had higher rate of IVH grade 3 and 4 (26.2% vs 2.9%, p = 0.005) and were more likely to undergo surgery (49.2% vs 26.5%, p = 0.031). LO-NEC infants had a higher incidence of previous bloodstream infections (35.3% vs 8.2%, p = 0.002) compared to EO-NEC. In multivariable analysis models, surgical intervention was associated with EO-NEC (OR: 4.627, p = 0.013) as well as PDA and positive blood culture prior to the NEC episode.

CONCLUSIONS

Our data support the hypothesis that EO-NEC has significant different clinical and microbiological attributes compared to LO-NEC.

Clinical presentation and transmission of postnatal cytomegalovirus infection in preterm infants

BACKGROUND

Preterm infants are at greater risk of developing postnatal cytomegalovirus (CMV) infection with serious symptoms. Breast milk is the main route of CMV transmission in populations with a high seroprevalence.

OBJECTIVES

This study aimed to investigate the clinical presentation and transmission of postnatal CMV (pCMV) infection via breast milk in preterm infants under the specific setting of our neonatal intensive care unit (NICU).

METHODS

The medical records of 147 preterm infants were reviewed retrospectively, and their clinical characteristics and outcomes were analyzed. Breast milk and infant urine samples were collected every two weeks until discharge, and the kinetics of CMV loads were evaluated using a polymerase chain reaction assay.

RESULTS

Seventeen infants (11.6%) were diagnosed with pCMV infection during the study period. In comparison between the pCMV and control groups, the mean birth weight was significantly lower in the pCMV group than in the control group (1084.1 ± 404.8 g vs. 1362.5 ± 553.8 g, P = 0.047). Four (23.5%) patients had leukocytopenia, six (35.3%) had neutropenia, three (17.6%) had thrombocytopenia, and two (11.8%) had hyperbilirubinemia in the pCMV group. Five patients were treated with antiviral agents, and their CMV load in the urine decreased after treatment. CMV loads peaked at 3-5 weeks in breast milk, whereas they peaked at 8-12 weeks of postnatal age in infants' urine. A comparison between the median CMV load in breast milk from the pCMV and control groups revealed a significant difference (P = 0.043).

CONCLUSION

Most preterm infants with pCMV infection present a favorable clinical course and outcomes. A high CMV viral load in breast milk is associated with transmission. Further studies are warranted to prevent transmission and severe pCMV infections in preterm infants.

Pulmonary hypertension with bronchopulmonary dysplasia: Aichi cohort study

BACKGROUND

The incidence of pulmonary hypertension (PH) associated with bronchopulmonary dysplasia (BPD) has not been investigated in regional cohorts. The aim of this study was to clarify the incidence of PH associated with BPD in all very low birthweight infants (VLBWIs) born during the study period in Aichi Prefecture, Japan.

METHODS

We conducted a retrospective observational cohort study of all VLBWIs born in Aichi Prefecture. The inclusion criteria were VLB, birth between 1 January 2015 and 31 December 2015, and admission to any neonatal intensive care unit in Aichi Prefecture. BPD28d and BPD36w were defined as the need for supplemental oxygen or any respiratory support at 28 days of age or 36 weeks of postmenstrual age (PMA). The primary outcome was the incidence of PH after 36 weeks' PMA (PH36w) in VLBWIs with BPD28d and BPD36w. The secondary outcomes were the clinical factors related to PH36w in BPD36w patients. Mann-Whitney U-test and Fisher's exact test were used for univariate analysis. Differences were considered statistically significant at P < 0.05. Risk ratio (RR) and 95% confidence interval (CI) were also evaluated.

RESULTS

A total of 441 patients were analyzed. A total of 217 and 131 patients met the definition of BPD28d and BPD36w, respectively. Nine patients were diagnosed with PH36w (4.2% and 6.9% of the BPD28d and BPD36w patients, respectively). The presence of oligohydramnios (RR, 2.71; 95% CI: 1.55-4.73, P = 0.014) and sepsis (RR, 3.62; 95% CI: 1.51-8.63, P = 0.025) was significant in the PH36w patients.

CONCLUSIONS

The incidence of PH36w was 4.2% and 6.9% in the BPD28d and BPD36w patients, respectively. Oligohydramnios and sepsis were significantly associated with PH36w in VLBWIs.

A prediction model of pulmonary hypertension in preterm infants with bronchopulmonary dysplasia

OBJECTIVE

Pulmonary hypertension (PH) is a severe cardiovascular complication of bronchopulmonary dysplasia (BPD) that contributes to the high mortality rates for preterm infants. The objective of this study is to establish a prediction model of BPD-associated PH (BPD-PH) by integrating multiple predictive factors for infants with BPD.

METHOD

A retrospective investigation of the perinatal clinical records and data of echocardiography in all the preterm infants with BPD was performed from January 2012 to December 2019. A prediction model of BPD-PH was established based on the univariate and multivariate logistic regression analysis of the clinical data and evaluated by using the area under the receiver operating characteristic (ROC) curve (AUC), combined with the Hosmer-Lemeshow (HL) test. Internal validation was performed with bootstrap resampling.

RESULT

A total of 268 infants with BPD were divided into the BPD-PH group and the no-PH group. Multivariate logistic regression analysis showed that the independent predictive factors of BPD-PH were moderate to severe BPD, small for gestational age, duration of hemodynamically significant patent ductus arteriosus ≥ 28 days, and early PH. A prediction model was established based on the β coefficients of the four predictors. The area under the ROC curve of the prediction model was 0.930. The Hosmer-Lemeshow test (p = 0.976) and the calibration curve showed good calibration.

CONCLUSION

The prediction model based on the four risk factors predicts the development of BPD-PH with high sensitivity and specificity and might help clinicians to make individualized interventions to minimize the disease risk.

Early vs late initiation of sodium glycerophosphate: Impact on hypophosphatemia in preterm infants <32 weeks

BACKGROUND & AIMS

Early electrolyte and mineral imbalances have emerged as a conspicuous problem in very preterm babies since the revision of nutrition guidelines and the eventual implementation of early aggressive parenteral nutrition (PN). We opted to carry out a study with the introduction of phosphorus as sodium glycerophosphate in PN from the first day onward to reveal the impact on serum phosphorus and calcium levels following the surge in the incidence of hypercalcemia and hypophosphatemia.

METHODS

In this single-center, prospective, observational cohort study, inborn babies <32 gestational weeks and <1500 g between August 2017 and July 2018 were enrolled consecutively. Infants born in the first 6-month of this period were initiated PN (Early phosphorus group) containing phosphorus (1 mmol P as sodium glycerophosphate/100 ml PN) immediately after birth, and in the latter six-months, mineral-free standard PN (Control group) was commenced up until 48 h of life. Parenteral nutritional prescriptions of both groups were similar in terms of macro and micronutrient intakes except for early phosphorus, calcium, and sodium. Serum mineral and electrolyte levels were measured on Days 1-3-7 and compared between the groups. The primary outcome was the presence of hypophosphatemia in the first week of life. The secondary outcome was hypercalcemia, preterm morbidity, and mortality.

RESULTS

A total of 261 infants were included in this study. There were 130 babies in Early phosphorus group and 131 in control group. Gestational ages (28.79 ± 2.1 vs 28.46 ± 2.2 weeks, respectively) and birth weights (1138 ± 273 vs 1090 ± 274 g, respectively) were similar in the groups. Mean serum phosphorus levels were higher on all days in Early phosphorus group (p < 0.001). Early phosphorus group had a lower incidence of hypophosphatemia on days 1-3 and 7 (p < 0.001). The percentage of hypercalcemic infants was significantly lower in Early phosphorus group on day 3 (p < 0.001). No difference was noted in terms of hypernatremia in the groups.

CONCLUSIONS

Adding phosphorus to PN in the first hours of life reduced the frequency of hypophosphatemia and hypercalcemia without any surge in hypernatremia or morbidity. Nutrition guidelines need to be revised accordingly in terms of early mineral/electrolyte supplementation.

Characteristics of Surgical Necrotizing Enterocolitis: Is It Different from Medical Necrotizing Enterocolitis? A Single-Center Retrospective Study

(1) Background: Necrotizing enterocolitis (NEC) is one of the leading causes of death in newborns despite improvements in the care of critically ill neonates. Approximately 50–70% of the cases are managed by medical therapy. However, the remaining patients require surgical intervention. The purpose of our study was to analyze the factors associated with patients requiring surgical treatment compared to patients requiring only medical treatment; (2) Method: Patients diagnosed with necrotizing enterocolitis over a period of 14 years (January 2003–December 2016) in a single tertiary referral children’s hospital were retrospectively enrolled. Demographics and clinical data were collected through the medical record and were analyzed using Pearson’s χ2 test, t-tests, and linear regression; (3) Results: A total of 189 NEC patients were analyzed. In the surgical NEC group, gestational age was lower (p = 0.018), body weight at birth was lower (p = 0.034), comorbidity with respiratory distress syndrome (RDS) was higher (p = 0.005), the days of antibiotic use were greater (p = 0.014), the percentage of breast milk feeding was lower (p = 0.001), and the length of hospital stay was longer (p < 0.000). The in-hospital mortality between the two groups was not significantly different (p = 0.196). In multivariate logistic analysis, breast milk feeding remained less associated with surgical NEC (OR = 0.366, 95% CI: 0.164–0.817), whereas the length of hospital stay was more associated with surgical NEC (OR = 1.010, 95% CI: 1.001–1.019); (4) Conclusion: Comparing medical and surgical NEC, a significantly lower percentage of surgical NEC patients were fed breast milk and their hospital stays were longer.

Cytotoxic Lactalbumin-Oleic Acid Complexes in the Human Milk Diet of Preterm Infants

Frozen storage is necessary to preserve expressed human milk for critically ill and very preterm infants. Milk pasteurization is essential for donor milk given to this special population. Due to these storage and processing conditions, subtle changes occur in milk nutrients. These changes may have clinical implications. Potentially, bioactive complexes of unknown significance could be found in human milk given to preterm infants. One such complex, a cytotoxic α-lactalbumin-oleic acid complex named "HAMLET," (Human Alpha-Lactalbumin Made Lethal to Tumor cells) is a folding variant of alpha-lactalbumin that is bound to oleic acid. This complex, isolated from human milk casein, has specific toxicity to both carcinogenic cell lines and immature non-transformed cells. Both HAMLET and free oleic acid trigger similar apoptotic mechanisms in tissue and stimulate inflammation via the NF-κB and MAPK p38 signaling pathways. This protein-lipid complex could potentially trigger various inflammatory pathways with unknown consequences, especially in immature intestinal tissues. The very preterm population is dependent on human milk as a medicinal and broadly bioactive nutriment. Therefore, HAMLET's possible presence and bioactive role in milk should be addressed in neonatal research. Through a pediatric lens, HAMLET's discovery, formation and bioactive benefits will be reviewed.

Newborns with Bloody Stools-At the Crossroad between Efficient Management of Necrotizing Enterocolitis and Antibiotic Stewardship

The onset of bloody stools in neonates often results in antibiotic treatment for suspected necrotizing enterocolitis (NEC). Food protein-induced allergic proctocolitis (FPIAP) is an often-neglected differential diagnosis. We performed a retrospective analysis of antibiotic exposure at our tertiary center from 2011 to 2020 that included three time periods of differing antimicrobial stewardship goals. We compared these data with the conventional treatment guidelines (modified Bell's criteria). In our cohort of 102 neonates with bloody stools, the length of antibiotic exposure was significantly reduced from a median of 4 to 2 days. The proportion of treated neonates decreased from 100% to 55% without an increase in negative outcomes. There were 434 antibiotic days. Following a management strategy according to modified Bell's criteria would have led to at least 780 antibiotic days. The delayed initiation of antibiotic treatment was observed in 7 of 102 cases (6.9%). No proven NEC case was missed. Mortality was 3.9%. In conclusion, with FPIAP as a differential diagnosis of NEC, an observational management strategy in neonates with bloody stools that present in a good clinical condition seems to be justified. This may lead to a significant reduction of antibiotic exposure. Further prospective, randomized trials are needed to prove the safety of this observational approach.

Quality Improvement Efforts Reduce Incidence of Surgical Necrotizing Enterocolitis and Related Deaths

OBJECTIVE

The aim of this study was to determine whether a regional quality improvement (QI) initiative decreased incidence and severity of surgical necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants.

STUDY DESIGN

A retrospective review of all VLBW infants who received care at one of the three hospitals involved in a NEC QI initiative from 2011 to 2016. Primary outcome was the number of surgical NEC cases per year. Secondary outcomes included associated outcomes and mortality.

RESULTS

Sixty-three infants with either a diagnosis of Stage III NEC (n = 40) or spontaneous intestinal perforation (SIP) (n = 23) were included. The incidence of medical and surgical NEC and the mortality rate of infants with surgical NEC decreased over time. Incidence and mortality of SIP did not significantly change.

CONCLUSION

A regional QI bundle to reduce the overall incidence of NEC also significantly decreased the incidence of surgical NEC and all-cause mortality of infants diagnosed with surgical NEC.

KEY POINTS

· QI reduces surgical necrotizing enterocolitis.. · Reduction in NEC rate improves mortality.. · Human milk does not change SIP incidence..

Risk factors and clinical characteristics for bronchopulmonary dysplasia associated pulmonary hypertension in very-low-birth-weight infants

BACKGROUND

Pulmonary hypertension (PH) is a common complication of bronchopulmonary dysplasia (BPD) in very-low-birth-weight infants (VLBWIs). Although recent studies have increased awareness that PH contributes significantly to the high morbidity and mortality of BPD, the risk factors and clinical characteristics for PH in VLBWIs are little known.

OBJECTIVES

To investigate the risk factors and clinical characteristics for BPD-associated pulmonary hypertension (BPD-PH) in VLBWIs.

METHODS

A retrospective case-control observational study of VLBWIs with BPD admitted to a neonatal intensive care unit (NICU) over 4 years. According to echocardiograms confirming elevated pulmonary artery pressure after 28 days after birth, we divided BPD infants into PH group (n = 18) and non-PH group (n = 65). We compared pre- and postnatal characteristics between VLBWIs with or without PH. Multivariable logistic regression analysis was conducted with backward selection.

RESULTS

A total of 83 infants with BPD were divided into PH group (n = 18) or non-PH group (n = 65). The average birth weight of the infants with BPD was 1078.1 g. Compared with those infants of the non-PH group, the birth weight of BPD-PH infants was significantly lower (968.1 ± 187.7 vs. 1108.5 ± 185.8, P = 0.006). Infants in the PH group had a higher incidence of patent ductus arteriosus (PDA) and underwent longer durations of oxygen therapy and mechanical ventilation compared to those in the non-PH group. In all subjects, birth weight (OR 0.995; 95% CI 0.991-0.999; P = 0.025) and PDA (OR 13.355; 95% CI 2.950-60.469; P = 0.001) were found to be specific risk factors for BPD-PH in this cohort.

CONCLUSIONS

The study shows PDA and birth weight are specific risk factors for BPD-PH in VLBWIs.

Evaluation of the Mortality and Morbidity of Premature Infants During a Five-Year Period in the Neonatal Intensive Care Unit

Background Premature birth is the most important cause of perinatal mortality and morbidity. This study aimed to evaluate mortality and morbidity in premature infants over a five-year period at a university hospital providing tertiary intensive care health services. Methodology All premature infants born alive at ≤37 gestational weeks and hospitalized in neonatal intensive care units were included in the study. Data such as maternal and perinatal characteristics, characteristics of the newborn, respiratory and related problems, neonatal morbidities, and causes of death were retrieved retrospectively from file records. Results A total of 1,780 patients (53.7% male and 46.3% female) were included in the study. High-risk pregnancy was present in 55% of women. Respiratory distress syndrome (RDS) developed in 50.4% of the patients, intracranial hemorrhage in 8.4%, and necrotizing enterocolitis in 5.6%. Mortality was observed in 20.9% of the patients. The most frequent cause of death was RDS and related complications (11.8%), and 66.4% of mortality occurred during the early neonatal period, that is, the first 24 hours of life. Conclusions High-risk pregnancies were significantly associated with neonatal morbidity and mortality. Therefore, the management of maternal health factors should be the priority for controlling neonatal mortality.

Multi-centre, randomised non-inferiority trial of early treatment versus expectant management of patent ductus arteriosus in preterm infants (the BeNeDuctus trial): statistical analysis plan

Background

Controversy exists about the optimal management of a patent ductus arteriosus (PDA) in preterm infants. A persistent PDA is associated with neonatal mortality and morbidity, but causality remains unproven. Although both pharmacological and/or surgical treatment are effective in PDA closure, this has not resulted in an improved neonatal outcome. In most preterm infants, a PDA will eventually close spontaneously, hence PDA treatment potentially increases the risk of iatrogenic adverse effects. Therefore, expectant management is gaining interest, even in the absence of convincing evidence to support this strategy.

Methods/design

The BeNeDuctus trial is a multicentre, randomised, non-inferiority trial assessing early pharmacological treatment (24–72 h postnatal age) with ibuprofen versus expectant management of PDA in preterm infants in Europe. Preterm infants with a gestational age of less than 28 weeks and an echocardiographic-confirmed PDA with a transductal diameter of > 1.5 mm are randomly allocated to early pharmacological treatment with ibuprofen or expectant management after parental informed consent.

The primary outcome measure is the composite outcome of mortality, and/or necrotizing enterocolitis Bell stage ≥ IIa, and/or bronchopulmonary dysplasia, all established at a postmenstrual age of 36 weeks. Secondary short-term outcomes are comorbidity and adverse events assessed during hospitalization and long-term neurodevelopmental outcome assessed at a corrected age of 2 years. This statistical analysis plan focusses on the short-term outcome and is written and submitted without knowledge of the data.

Trial registration

ClinicalTrials.gov NTR5479. Registered on October 19, 2015, with the Dutch Trial Registry, sponsored by the United States National Library of Medicine Clinicaltrials.gov NCT02884219 (registered May 2016) and the European Clinical Trials Database EudraCT 2017-001376-28.

Hypoxia: The "Invisible Pusher" of Gut Microbiota

Oxygen is important to the human body. Cell survival and operations depend on oxygen. When the body becomes hypoxic, it affects the organs, tissues and cells and can cause irreversible damage. Hypoxia can occur under various conditions, including external environmental hypoxia and internal hypoxia. The gut microbiota plays different roles under hypoxic conditions, and its products and metabolites interact with susceptible tissues. This review was conducted to elucidate the complex relationship between hypoxia and the gut microbiota under different conditions. We describe the changes of intestinal microbiota under different hypoxic conditions: external environment and internal environment. For external environment, altitude was the mayor cause induced hypoxia. With the increase of altitude, hypoxia will become more serious, and meanwhile gut microbiota also changed obviously. Body internal environment also became hypoxia because of some diseases (such as cancer, neonatal necrotizing enterocolitis, even COVID-19). In addition to the disease itself, this hypoxia can also lead to changes of gut microbiota. The relationship between hypoxia and the gut microbiota are discussed under these conditions.

hPSC-derived organoids: models of human development and disease

Organoids derived from human pluripotent stem cells (hPSCs) have emerged as important models for investigating human-specific aspects of development and disease. Here we discuss hPSC-derived organoids through the lens of development-highlighting how stages of human development align with the development of hPSC-derived organoids in the tissue culture dish. Using hPSC-derived lung and intestinal organoids as examples, we discuss the value and application of such systems for understanding human biology, as well as strategies for enhancing organoid complexity and maturity.

Necrotizing enterocolitis and its association with the neonatal abstinence syndrome

OBJECTIVE:

The purpose of this study was to describe an identified association between necrotizing enterocolitis (NEC) and prenatal opioid exposure with neonatal abstinence syndrome (NAS) in late preterm and full-term neonates.

STUDY DESIGN:

In this single-center retrospective cohort study, we analyzed inborn neonates with the diagnosis of NEC discharged from 2012 through 2017. We compared infants with NEC > 35 weeks’ gestation to those with NEC<35 weeks’ gestation. We compared gestational age, birth weight, age of onset of symptoms, and incidence of prenatal drug exposure between groups. Significance was determined using Mann-Whitney and Fisher’s exact tests.

RESULTS:

Over the study period, 23 infants were identified with NEC, 9 (39%) were babies > 35 weeks at birth and 14 (61%) < 35 weeks. Those > 35 weeks had a higher birth weight, earlier onset of symptoms, and a higher percentage of prenatal exposure to opioids compared to those < 35 weeks’ gestation. We further described seven infants with late gestational age onset NEC associated with prenatal opioid exposure.

CONCLUSIONS:

In this cohort of infants with NEC discharged over a 6 year period we found a higher than expected percentage of infants born at a later gestational age. We speculate that prenatal opioid exposure might be a risk factor for NEC in neonates born at > 35 weeks.

Maternal N-acetyl-cysteine prevents neonatal brain injury associated with necrotizing enterocolitis in a rat model

INTRODUCTION

Preterm infants with necrotizing enterocolitis (NEC) are at increased risk of cerebral injury and neurodevelopmental dysfunction. N-acetyl-cysteine (NAC) is a known anti-inflammatory and antioxidant agent. Currently, there is no prophylactic treatment in clinical use to prevent NEC and its neurodevelopmental sequelae. We sought to determine whether brain inflammation/apoptosis accompanies NEC systemic inflammation, and whether it can be attenuated by maternal NAC treatment during pregnancy and/or in the neonatal period in a rat model.

MATERIAL AND METHODS

An established NEC newborn model (hypoxia 5% O₂ for 10 min and formula feeding thrice daily, beginning on day 1 for 4 days) was used in Sprague-Dawley rat pups (n = 32). An additional group of pups (n = 33) received NAC (300 mg/kg intraperitoneal thrice daily) in addition to NEC conditions (NEC-NAC). Control pups (n = 33) were nursed and remained with the dam in room air. Two additional groups included pups of dams treated once daily with NAC (300 mg/kg intravenous) in the last 3 days of pregnancy. After birth, pups were randomized into NAC-NEC (n = 33) with NEC conditions and NAC-NEC-NAC (n = 36) with additional postnatal NAC treatment. Pups were sacrificed on the fifth day of life. Pup serum interleukin (IL)-6 protein levels, and brain nuclear factor kappa B (NF-κB) p65, neuronal nitric oxide synthase (nNOS), Caspase 3, tumor necrosis factor alpha (TNF-α), IL-6 and IL-1β protein levels were determined by ELISA, western blot and TUNEL staining, and the groups were compared using analysis of variance (ANOVA).

RESULTS

NEC pups had significantly increased serum IL-6 levels compared with the control group as well as increased neuronal apoptosis and brain protein levels of NF-κB, nNOS, Caspase 3, TNF-α, IL-6 and IL-1β compared with control. In all NAC treatment groups, levels of serum IL-6, neuronal apoptosis and brain NF-κB, nNOS, Caspase 3, TNF-α, IL-6 and IL-1β protein levels were significantly reduced compared with the NEC group. The most pronounced decrease was demonstrated within the NAC-NEC-NAC group.

CONCLUSIONS

NAC treatment can attenuate newborn inflammatory response syndrome and decrease offspring brain neuroapoptosis and inflammation in a rat model of NEC by inhibition of NF-κB, nNOS and Caspase 3 pathways.