Pediatric Research

Objectives: Using a nationally representative database of U.S. hospitalizations, we aimed to (1) characterize contemporary trends in hypoxic-ischemic encephalopathy (HIE) prevalence by severity, therapeutic hypothermia (TH) utilization, and associated in-hospital mortality; and (2) examine the association between TH and mortality by HIE severity and gestational age (GA), focusing on 35- and 36-weeks GA. Methods: We analyzed newborn hospitalizations from the National Inpatient Sample, 2016-2023. Unspecified, mild, moderate, and severe HIE were identified using ICD-10-CM diagnosis codes P91.60-P91.63; and 35- and 36-weeks GA using codes P07.38-P07.39. TH was identified using ICD-10-PCS codes 6A4Z0ZZ and 6A4Z1ZZ. Survey-weighted multivariable generalized linear models with marginal standardization were used to estimate adjusted mortality risk differences (RD) with surprisal (S) values, and assess whether associations between TH and mortality differed by HIE severity across GA strata. Results: Among 29,767,238 hospital discharges, HIE was identified in 66,535 neonates (2.24 per 1,000), and TH used in 19.2% of HIE cases. In-hospital mortality was 9.74% among all HIE cases and 6.65% among TH-treated neonates. From 2016-23, HIE prevalence nearly doubled (1.58 to 3.01 per 1,000; p-for-trend <0.001) and TH utilization more than doubled (0.33 to 0.74 per 1,000; p-for-trend <0.001), while TH use as a proportion of HIE remained stable (17.8%-20.8%; p-for-trend=0.39). HIE severity distribution was: mild (15%), moderate (29.4%), severe (18.3%), and unspecified (37.3%), with moderate HIE increasing over time (22.3%-33.5%). Crude mortality was consistently highest for severe HIE (range: 33.65%-35.25%). Among infants with severe HIE, TH was associated with reduced mortality overall (RD -10.12%; 95% CI -14.86, -5.39; p<0.001; S=15.12), and specifically at 36-weeks GA (RD -21.98%; 95% CI -35.85, -8.12; p=0.002; S=9.06), but not at 35-weeks (RD -1.83%; 95% CI -21.2, 17.55; p=0.86; S=0.22). Conclusions: TH was associated with mortality reduction in severe HIE overall and at 36-weeks GA, but this benefit remains uncertain at 35-weeks GA.

Importance: Expectant management for preterm prelabor rupture of membranes (PPROM) is guided primarily by gestational age (GA), yet whether the association between latency duration and neonatal outcomes varies among pregnancies remains uncertain. Objective: To characterize heterogeneous associations between latency duration and neonatal outcomes after PPROM and identify maternal and fetal characteristics associated with the largest estimated benefit. Design: Nationwide registry-based retrospective cohort study using restricted cubic spline regression and causal forest analysis. Data were analyzed from July 2025 to July 2026. Setting: The Korean Neonatal Network (KNN), a nationwide registry of infants born before 32 weeks' gestation or with a birth weight less than 1,500g, from 2013 to 2023. Participants: A total of 7,057 neonates born after PPROM were included. Exposures: Latency duration, defined as the number of days from PPROM diagnosis to delivery (0-118 days). Main Outcomes and Measures: Neonatal Health Index (NHI), an ordinal composite from 0 (death) to 8 (survival free of 7 major neonatal morbidities: intraventricular hemorrhage grades 3-4, periventricular leukomalacia, retinopathy of prematurity stage [&ge;]3, bronchopulmonary dysplasia, pulmonary hypertension, necrotizing enterocolitis stage [&ge;]2, and sepsis). Results: Among 7,057 neonates (median [IQR] maternal age, 34.0 [31.0-36.0] years; GA at PPROM, 27.0 [24.0-29.0] weeks; latency duration, 2.0 [0.0-8.0] days), longer latency was associated with better neonatal health, reflected by higher NHI (n = 6,872), in a non-linear, GA-dependent pattern (overall P < .001; nonlinearity P < .001). Causal forest analysis estimated an average partial effect of a 0.078-point increase in NHI per additional day of latency (P < .001), with significant heterogeneity across individuals (P < .001). GA at PPROM, oligohydramnios, and maternal age were the strongest modifiers; neonates with GA at PPROM of 26 weeks or less, no oligohydramnios, and maternal age younger than 30 years had an estimated treatment effect 28.0% greater than the rest of the cohort (0.121 vs 0.094 NHI points per latency-day). Conclusions and Relevance: Associations between neonatal outcomes and prolonged latency after PPROM were positive overall but heterogeneous in magnitude, varying by GA at PPROM, oligohydramnios status, and maternal age. These findings support tailoring expectant management after PPROM according to individual patient characteristics rather than a uniform, GA-based strategy.

Background: Cyclooxygenase (COX) inhibitors have been used to treat hemodynamically significant patent ductus arteriosus (PDA) in preterm infants. If the PDA remains hemodynamically significant after an initial course, additional courses of COX inhibitors or surgical intervention are considered. This systematic review evaluates PDA closure rates and safety after repeated courses of COX inhibitors in preterm infants. Methods: Embase, Medline, and two other databases were searched through April 2026 (pre-registered in PROSPERO [CRD42023454003]). Studies reporting PDA closure rates after two or more courses of COX inhibitors were included. Risk of bias was assessed using Joanna Briggs Institute tools. Meta-analyses with random-effects models were performed to calculate the proportions of PDA closure. Multilevel mixed-effects meta-regression was used to compare closure rates across treatment courses while accounting for within-study correlations. Results: A total of 33 studies were included. The PDA closure rates after the first, second, and third courses of COX inhibitors were 62% (95% confidence interval [CI] 57-67%), 46% (95% CI 40-52%; p < 0.001 vs the first course), and 38% (95% CI 27-51%; p = 0.001 vs the first course), respectively. Lower closure rates with repeated courses were also observed across most subgroups (extremely preterm/extremely low birth weight, ibuprofen, indomethacin, and intravenous administration), except for the second course of oral administration. Data on adverse events were limited, preventing meta-analysis. Conclusions: PDA closure rates after the second and third courses of COX inhibitors were lower than those after the first course in preterm infants. Evidence regarding the safety of repeated courses remains limited.

Background Neonates with critical congenital heart disease (CCHD) are vulnerable to feeding-related complications including necrotizing enterocolitis (NEC). Human milk and direct breastfeeding (BF) may offer protection, but multisite evidence is limited. We aimed to determine relationships between the proportion of human milk received (ie, human milk percentage) or BF frequency during the neonatal period and NEC, sepsis, infectious complications, or length of stay (LOS). We also determined whether bovine-derived fortification or formula initiation was associated with NEC. Methods This retrospective study included neonates from 25 US pediatric centers who underwent surgery with cardiopulmonary bypass. Outcomes were NEC (modified Bell's Stages II-III), sepsis, infection, and LOS. Disease risk score case-control matching and energy balancing weighted regression balanced multiple relevant covariates. Results Among 822 neonates, the percentage of human milk received during the neonatal period was not associated with NEC, sepsis or infection. Initiation of fortification or formula was associated with 3-fold higher odds of developing NEC within 5 days (OR:3.10, 95%CI:1.10-8.12, p=0.025). In energy balancing weighted regression models, higher neonatal human milk percentage and more frequent BF were strongly associated with shorter LOS: 100% versus 0% human milk with 9.33 days shorter (4.47-14.19, p<0.001); each additional BF session with 0.48 days shorter (0.31-0.65, p<0.001). Conclusions In this multisite cohort, fortification or formula initiation was associated with increased odds of NEC; and neonatal human milk percentage and BF with shorter LOS. Given limited evidence to guide practice, caution in introducing bovine-derived formula for high-risk infants with CCHD may be warranted.

Objective: To identify factors associated with predischarge morbidity and mortality among small for gestational age infants. Study Design: We conducted a retrospective single-center cohort study of small for gestational age infants admitted to a level IV neonatal intensive care unit. We determined the association of clinical characteristics, congenital anomalies, and genetic disorders with the primary outcome of predischarge morbidity or mortality and characterized morbidity and mortality across congenital anomaly subgroups. Results: Among 293 small for gestational age infants, 18 (6.1%) had a genetic disorder and 103 (35.2%) had a major congenital anomaly, with congenital heart disease (CHD) representing the largest subgroup. The primary outcome of morbidity or mortality occurred in 93 infants (31.7%); 74 infants (25.3%) experienced morbidity and 19 (6.5%) died. CHD (adjusted odds ratio [aOR]: 16.5, 95% CI 6.44-45.7) and multiple congenital anomalies (aOR: 17.8, 95% CI 4.64-71.1) were found to be strongly associated with morbidity or mortality, after accounting for sex, maternal race, and intubation > 7 days. Statistically significant associations were also found with the presence of musculoskeletal anomalies as well as genetic disorders in infants without congenital anomalies, though in limited sample sizes. CHD was the largest contributor to morbidity, whereas multiple congenital anomalies accounted for the greatest proportion of mortality. Infants with abdominal wall defects and central nervous system anomalies experienced no morbidity or mortality. Conclusion: Congenital heart disease and multiple congenital anomalies were strongly associated with morbidity and mortality among SGA infants, whereas the degree of SGA alone was not. These findings suggest that risk is not explained by the degree of SGA alone and may be more strongly associated with congenital disease and other underlying factors.

Background and Purpose: Neonatal hypoxia-ischemia (NHI) is a leading cause of mortality and long-term neurodevelopmental disability. Therapeutic hypothermia (TH) is currently the only established treatment for NHI; however, its efficacy remains limited, underscoring the need for adjunctive neuroprotective strategies. Lactate is now regarded as a major metabolic substrate of the brain and has previously been shown to exert neuroprotective effects following experimental NHI. We investigated whether lactate enhances hypothermia-induced neuroprotection and evaluated the optimal timing of administration and potential underlying mechanisms. Methods: Postnatal day 7 Wistar rats were subjected to NHI using the Rice-Vannucci model and treated with TH alone (2h at 32{degrees}C), sodium L-lactate alone, or combined L-lactate-TH. Animals underwent longitudinal magnetic resonance imaging (MRI) and behavioral assessments, complemented by histological, immunohistochemical, and Western blot analyses, including assessment of protein lactylation. The effect of sodium L-lactate administration timing relative to TH was also evaluated. Results: Lactate significantly enhanced the neuroprotective effects of TH, particularly when administered before hypothermia, resulting in greater lesion recovery, reduced neuroinflammation and apoptotic cell death, preserved neuronal integrity, and improved long-term motor and cognitive outcomes. Combined treatment preserved neuronal lactate transporter, prevented NHI-induced astrocytic glutamate transporter upregulation, modulated lactylation markers, supporting coordinated metabolic and epigenetic adaptations following NHI. Conclusions: Early lactate administration enhances the neuroprotective efficacy of TH following NHI. These findings identify lactate as a promising adjunct to TH and support its translational potential as a metabolic strategy to improve outcomes following NHI brain injury.

Background: Optimal arterial oxygen targets after return of spontaneous circulation (ROSC) in pediatric out-of-hospital cardiac arrest (OHCA) remain uncertain. We examined whether arterial oxygen tension on the first arterial blood gas after ROSC is associated with neurological or survival outcomes. Methods: Using the Japanese Association for Acute Medicine OHCA Registry, we retrospectively studied pediatric patients (<18 years) with OHCA in whom ROSC was confirmed at or after hospital arrival. Patients were categorized by PaO? on the first arterial blood gas after ROSC as normoxemia (60?200 mmHg) or hyperoxemia (>200 mmHg). Missing covariate data were handled using multiple imputation, and associations were estimated using inverse probability-weighted logistic regression. Outcomes were favorable neurological status at 30 days, defined as a Pediatric Cerebral Performance Category score of 1?3, and 30-day survival. Multiple sensitivity analyses were performed, including analyses using an alternative PaO? threshold, restricting the timing of PaO? measurement, and excluding extracorporeal cardiopulmonary resuscitation cases. Results: A total of 189 patients were included (95 normoxemia, 94 hyperoxemia). A favorable neurological outcome occurred in 21 of 95 (22.1%) normoxemia and 13 of 94 (13.8%) hyperoxemia patients, and 30-day survival in 40 of 95 (42.1%) and 42 of 94 (44.7%), respectively. After weighting, covariate balance was achieved with standardized mean differences below 0.1. Hyperoxemia was not significantly associated with favorable neurological outcome (adjusted odds ratio [aOR] 0.94, 95% confidence interval [CI] 0.49?1.77) or 30-day survival (aOR 1.49, 95% CI 0.88?2.54). Sensitivity analyses yielded consistent results. Conclusions: Early hyperoxemia after ROSC was not significantly associated with neurological or survival outcomes in pediatric out-of-hospital cardiac arrest. These findings suggest that a single early PaO? measurement may be insufficient to characterize the clinical impact of oxygen exposure after resuscitation. Future research should focus on phase-specific and individualized oxygen management incorporating serial physiological assessment.

Background: Infants <30 weeks gestational age (very preterm (VPT)), are at risk of experiencing multiple serious neonatal morbidities. These morbidities impart serious biological stress, which may be reflected in dysregulated protein expression even after the morbidities have resolved. Recent studies suggest that DNA methylation-based predictors of circulating proteins may reflect the molecular effects of neonatal adversity. The objective of this study is to examine associations between DNA methylation-derived EpiScores, which are externally trained methylation signatures that proxy circulating protein levels, and neonatal morbidity burden in children born VPT. Buccal DNA methylation was obtained at NICU discharge in 537 infants from the NOVI cohort. A total of 111 EpiScores were calculated and tested for association with multimorbidity (0-1 vs. [&ge;] 2 morbidities) using adjusted linear regression models. Cross-tissue analyses in an external paired blood-buccal dataset (n=21) were used to identify EpiScores with moderate-to-strong correlations across tissues. Results: Eighteen EpiScores were nominally associated with multimorbidity (p < 0.05), with Melanoma-derived growth regulatory protein (MIA) with FDR < 0.05 (beta = 0.0023, p = 0.0004). In cross-tissue analyses, 35 EpiScores yielded r > 0.50 (p<0.05), 11 of which showed nominal associations with multimorbidity, including MIA. Overall, the morbidity-associated EpiScores reflected immune, inflammatory, metabolic, and growth-related pathways. Conclusions: Buccal DNA methylation-derived EpiScores capture biological signatures associated with neonatal morbidity burden in very preterm infants.

Introduction: The TREOCAPA (Prophylactic TREatment Of the duCtus Arteriosus in Preterm infants by Acetaminophen) trial was a pan-European, multi-centre, phase II/III trial investigating the impact of prophylactic paracetamol (also known as acetaminophen) given during the first 5 days of life for children born before 29 weeks' gestational age (GA) on survival to 36 weeks' post-menstrual age without severe neonatal morbidities. However, due to time restrictions, long-term follow-up was not planned as part of the initial trial despite recommendations for neonatal trials to include endpoints measuring efficacy after discharge from the neonatal unit and on-going debate about the long-term effects of paracetamol in the neonatal period. This protocol describes a study to follow-up participants in the TREOCAPA trial at 2 years corrected age initiated after the trial's onset. Methods and analysis: The TREOCAPA Long Term (TREOCAPA-LT) study population consists of all children included in the TREOCAPA phase III trial in centres in countries participating in the follow-up study who are aged between 23.5 and 27.5 months corrected age during the study period. Families are contacted by the clinical teams and a parent or guardian is invited to complete an internet-based (online) questionnaire. The primary outcome is cognition, as measured by the non-verbal Cognitive Scale standard score from the Parent Report of Children's Abilities-Revised (PARCA-R) questionnaire. Secondary outcomes are moderate to severe neurodevelopment, health service use and costs. Data will be analysed according to the study groups to which children were randomised in the original TREOCAPA RCT. Ethics and Dissemination: The TREOCAPA-LT protocol was first approved by ethics' committees in France (the study's sponsor) and subsequently by all participating countries. Results from TREOCAPA-LT will be published in open access journals in accordance with the funder's regulations. Registration: https://clinicaltrials.gov/study/NCT06064825

Background: Risk adjustment for disease severity in pediatric intensive care research commonly relies on clinical organ dysfunction scores requiring detailed clinical and laboratory information, which is often unavailable in administrative healthcare datasets. We therefore evaluated the feasibility of a coding-based Pediatric Organ Dysfunction Index (PODI) derived from International Classification of Diseases (ICD-10) and Operation and Procedure System (OPS) codes, for approximating sepsis-related organ dysfunction and adjusting for disease severity, using the pediatric Sequential Organ Failure Assessment (pSOFA) score as a reference standard. Methods: In this retrospective single-center cohort study, pediatric sepsis episodes treated between November 2011 and November 2021 were identified. Discrimination for in-hospital mortality and calibration were assessed. Agreement between PODI and pSOFA was quantified using Spearman's rank correlation, and organ-specific agreement using sensitivity, specificity, and predictive values. An expanded PODI incorporating additional ICD-10 and OPS codes was evaluated in sensitivity analyses. Results: A total of 488 pediatric sepsis episodes were included, with an in-hospital mortality of 14.1%. The PODI showed good discrimination for in-hospital mortality (AUC 0.85, 95% CI 0.80-0.89), comparable to the maximum pSOFA (pSOFAmax) (AUC 0.78, 95% CI 0.72-0.83) and superior to pSOFA at sepsis onset (pSOFAonset) (AUC 0.73, 95% CI 0.67-0.80). Agreement between PODI and pSOFA organ-specific components varied considerably across organ systems, with the highest sensitivity to detect pulmonary dysfunction. Correlation between both scores was moderate (0.54 for pSOFAonset and 0.60 for pSOFAmax), indicating that comparable predictive performance does not render the scores interchangeable. The expanded PODI improved organ-level sensitivity for selected components but did not meaningfully improve mortality discrimination. Conclusions: The standard PODI may represent a practical approach to adjust for organ dysfunction and therapy intensity in administrative datasets with ICD-10 coding where clinical and laboratory information is unavailable. Given only moderate agreement with the pSOFA, the PODI should be understood as a covariate for risk adjustment at the group level rather than as a substitute for clinical organ dysfunction scores in individual patients. Further validation and refinement in non-sepsis cohorts are required before broader implementation in large-scale administrative research can be recommended.

Objective: To compare self-weaning and dose-adjusted caffeine regimens in preterm infants discharged home on caffeine for apnea of prematurity (AOP). Design: A prospective cohort study. Setting: Tertiary neonatal unit and outpatient clinics, Karachi, Pakistan, April 2023 to July 2025. Patients: 204 preterm infants (<37 weeks' gestation) discharged home on caffeine for AOP; 94 self-weaning, 110 dose adjusted. Interventions: Self-weaning (absolute dose fixed, so mg/kg/day exposure declined with weight gain) versus dose-adjusted weaning (dose recalculated to current weight at each visit). Both were followed to 36 weeks postmenstrual age (PMA). Main outcome measures: Proportion continuing caffeine beyond 36 weeks PMA and caregiver-reported apnea after discontinuation. Results: Caffeine was continued beyond 36 weeks PMA in 68/94 self-weaning infants (72.3%) and 84/110 dose-adjusted infants (76.4%). No apnea was reported after discontinuation in either group, and all 204 infants survived to 36 weeks PMA. Apnea-related readmission on caffeine occurred in 1/94 (1.1%) versus 2/110 (1.8%). Weight at discontinuation was lower with self-weaning (1917 vs 2157g); the dose-adjusted group was more premature (mean 30.0 vs 30.7 weeks). After adjustment for gestational age and birth weight, regimen was not associated with continuation beyond 36 weeks (adjusted OR 0.82, 95% CI 0.43 to 1.57) or time to discontinuation (adjusted HR 1.21, 95% CI 0.91 to 1.60). Conclusions: Within a structured outpatient follow-up program, no post-discontinuation apnea was reported with either regimen,and apnea-related readmissions were infrequent. Self-weaning avoids repeated dose recalculation. A multicenter randomized trial with objective home monitoring is needed to determine the optimal timing of discontinuation.

Using routinely recorded ventilator data from 16 preterm infants with respiratory distress syndrome, dynamic compliance trajectories after surfactant administration were smoothed with a moving-median filter and characterized with a four-parameter logistic model; 10 infants showed sigmoidal improvement, and among 11 infants who received a second surfactant dose, 6 showed subsequent improvement, suggesting that this approach can visualize and quantify individual compliance recovery as a complementary tool to conventional clinical indicators.

Background: Vitamin B12 is essential for one-carbon metabolism, deoxyribonucleic acid (DNA) synthesis, and myelination, and inadequate maternal status during pregnancy may influence fetal growth and child neurodevelopment. Objective: To evaluate the association between maternal vitamin B12 status and perinatal and child neurodevelopmental outcomes. Methods: We conducted a systematic review and meta-analysis of observational studies and randomized clinical trials. The main outcomes were preterm birth, low birth weight, small for gestational age (SGA), and cognitive/global development. For binary outcomes, the natural logarithm of the relative risk (logRR) was the primary analytical effect measure; for neurodevelopment, Hedges g was used. Random-effects models were fitted, between-study variance was estimated by restricted maximum likelihood (REML), and inference used Knapp-Hartung (KH) adjustment. Results: For preterm birth, nine estimates yielded a pooled logRR of 0.190 (95% confidence interval [95% CI] KH: -0.046 to 0.427; p = 0.101; I2 = 19.2%). For low birth weight, nine estimates yielded a pooled logRR of 0.136 (95% CI KH: -0.013 to 0.286; p = 0.069; I2 = 4.8%). For SGA, six estimates yielded a pooled logRR of 0.047 (95% CI KH: -0.083 to 0.177; p = 0.397; I2 = 0%). Cognitive/global development, assessed in five independent studies, showed a pooled Hedges g of 0.266 (95% CI KH: 0.034 to 0.499; p = 0.034; I2 = 55.7%). Conclusions: logRR estimates for preterm birth and low birth weight were directionally compatible with higher risk among mothers with lower vitamin B12 availability, but their 95% CIs included the null. No consistent association was observed for SGA. Higher maternal vitamin B12 availability or supplementation was associated with a small favorable effect on cognitive/global development, with moderate heterogeneity.

Background: Infants with extremely low birth weight (ELBW) are at high risk for neurodevelopmental impairment, but the relationship between cerebellar structure and later developmental outcome remains incompletely defined. Methods: In this retrospective single-center study, we examined total cerebellar volume on clinically acquired brain magnetic resonance imaging (MRI) in ELBW infants while accounting for postmenstrual age (PMA) at imaging. Results: Of 65 infants screened, 42 were included. Mean gestational age at birth was 25.54 {+/-} 1.68 weeks, mean birth weight was 733.2 {+/-} 118.7 g, and mean PMA at MRI was 43.02 {+/-} 6.53 weeks (range, 31.57--68.00). Mean cerebellar volume was 22.17 {+/-} 9.63 cm. Independently adjudicated developmental outcomes comprised normal development in 16 infants, isolated or specific impairment in 12, and moderate/severe impairment in 14. Unadjusted cerebellar volumes did not differ across developmental groups (P = 0.490) or qualitative MRI categories (P = 0.875). However, the PMA-by-developmental-category interaction was significant (P = 0.002), with estimated cross-sectional slopes of 1.72, 1.56, and 0.39 cm per week, respectively. The interaction remained significant within 36--46 weeks PMA (n = 29; P = 0.011) and after adjustment for small-for-gestational-age (SGA) status. Sensitivity analyses indicated uncertainty in the stability of the interaction. Conclusions: These findings suggest that age-informed cerebellar volumetric patterns may provide developmental information not evident from average volumes alone and support prospective validation with standardized imaging and developmental assessments. As a result, cerebellar volumes obtained early in life may hold prognostic information for ELBW infants.

Abstract: Background: Children born very preterm (VPT) are at elevated risk for adverse neurobehavioral outcomes and are vulnerable to environmental exposures. We used untargeted metabolomics analysis to identify environmentally relevant metabolites associated with childhood behavioral problems and to characterize related endogenous metabolic pathways. Methods: We studied 226 children born <30 weeks gestation in a multi-site cohort study. Urine collected at age 4 was profiled using untargeted ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS). Associations between 30 exogenous environmental metabolites and behavioral problems score at age 4 were evaluated cross-sectionally using multivariable linear regression, followed by metabolome-wide association and pathway enrichment analyses. Results: Three exogenous metabolites were nominally associated with child behavior problems. Specifically, 2-(Acetylamino)-3-( henylthiol)propanoic acid was positively associated with overall ({beta}=1.42, p=0.006), externalizing ({beta}=1.50, p=0.006), and internalizing ({beta}=1.34, p=0.021) behavior problems. Diethofencarb was positively associated with overall ({beta}=0.34, p=0.018) and externalizing ({beta}=0.39, p=0.010) behavior problems, while protocatechuic acid was inversely associated with internalizing problems ({beta}=-0.68, p=0.027). No associations remained significant after false discovery rate (FDR) correction. Nevertheless, these metabolites were associated with 151, 131, and 530 endogenous metabolic features, respectively, at FDR<0.05, highlighting perturbations in lipid metabolism, mitochondrial energetics, inflammatory signaling, amino acid metabolism, and neuroactive pathways. Conclusions: Environmental metabolites associated with behavior problems were linked to broad endogenous metabolic differences relevant to neurodevelopment. These findings highlight potentially modifiable environmental influences, including exposures related to combustion-derived pollutants, pesticides, and dietary sources, that may contribute to behavioral vulnerability among children born very preterm

Rationale: Congenital central hypoventilation syndrome (CCHS) is most commonly caused by polyalanine repeat mutations in PHOX2B. The in vivo consequences of the short five-alanine expansion and the contribution of specific hindbrain lineages to the resulting respiratory phenotype remain poorly understood. Objectives: To characterize the neonatal phenotype caused by the Phox2b25Ala/+ mutation and determine the contribution of the MafB lineage associated with the r5-r6 hindbrain territory. Methods: We generated a conditional Phox2b25Ala allele and studied mice with constitutive or MafB-lineage activation. Neonatal survival, growth, gastric milk content, ventilation, and hypercapnic responses were assessed in vivo. Respiratory-network activity and responses to extracellular acidification were recorded in E18.5 isolated brainstem-spinal cord preparations, and retrotrapezoid nucleus (RTN) development was examined histologically. Measurements and Main Results: Constitutive Phox2b25Ala/+ pups exhibited high neonatal mortality, markedly impaired weight gain, reduced gastric milk scores, hypoventilation, increased apnea time, and blunted ventilatory responses to CO2. Embryonic preparations showed a slower respiratory rhythm, an impaired response to acidification, and severe RTN dysgenesis. Activation of the mutant allele in the MafB lineage was also associated with severe respiratory dysfunction, RTN dysgenesis, and early neonatal mortality. In contrast, postnatal weight gain was preserved among surviving MafB-lineage mutants, and the reduction in gastric milk scores was significantly attenuated compared with constitutive mutants. Conclusions: A short PHOX2B polyalanine expansion reproduces major respiratory features of CCHS in mice. Activating the mutant allele in the MafB lineage is sufficient to cause severe respiratory dysfunction and neonatal mortality, whereas postnatal weight gain is preserved among survivors.

Objective: To investigate sex-specific associations between DNA methylation (DNAm) of neurodevelopmental, stress-response, and dopaminergic pathway genes and need for pharmacological treatment for Neonatal Opioid Withdrawal Syndrome (NOWS) among opioid-exposed newborns. Study Design: Buccal swabs were collected at birth from 181 infants in the multi-site Child and Family Study (CAFS). DNAm was measured via pyrosequencing at CpG sites within promoter regions of neurodevelopmental (BDNF), stress-response (AVP, NR3C1, OXTR, FKBP5, SLC6A4), dopaminergic (DRD2, DRD4), and opioid signaling (OPRM1) genes. Need for pharmacological treatment for NOWS was obtained from medical records. We estimated robust linear regression models to investigate sex-specific associations of DNAm and need for NOWS treatment. Estimated marginal means quantified sex-specific DNAm differences by treatment status. Results: After correction for multiple testing, five CpG sites within DRD4 were significantly associated with need for pharmacological treatment, with four sites showing higher DNAm in treated infants and one showing lower DNAm. Significant sex-specific associations were identified within DRD4 and AVP. Conclusions: Epigenetic variation across multiple biological pathways contributes to variability in NOWS severity among infants with prenatal opioid exposure. The relationship between epigenetic variation and need for NOWS treatment may vary depending on infant sex.

Background Despite cerebrospinal fluid (CSF) analysis being the gold standard for definitively diagnosing meningitis, its practical application has presented considerable difficulties, especially in environments with limited resources. Cranial ultrasound (CUS), while not a replacement for CSF analysis, provides rapid imaging to identify meningeal irregularities. Nevertheless, achieving a timely diagnosis of meningitis, particularly in its nascent stages, remains problematic, and healthcare professionals exhibit a notably low awareness of CUS's utility in diagnosing this condition. Methods This was a prospective cohort that recruited 273 term mother-neonate pairs. The neonates were initially divided into those with sepsis-meningitis (exposure group) and those with sepsis (non-exposure group) based on clinical assessment done by the admitting team. The research team further divided the participants into 4 diagnostic subgroups based on CUS findings: positive CUS for meningitis, positive clinical diagnosis for meningitis, positive CUS & clinical diagnosis for meningitis and those with negative CUS & clinical diagnosis for meningitis /sepsis only. Data on socio-demographics, clinical characteristics, blood works and CSF analysis reports, neurologic deficits and mortality outcomes were recorded for each neonate. Descriptive and inferential statistics were performed. Results The 4 diagnostic subgroups based on CUS findings were: positive CUS for meningitis (24.5%), positive clinical diagnosis for meningitis (4.4%), positive CUS & clinical diagnosis for meningitis (6.6%) and those with negative CUS & clinical diagnosis for meningitis /sepsis only (64.5%). Overall, duration of hospitalization was 11 days (range 2-45 days; interquartile range [IQR] 6,16) and the median chronological age of the neonates was 13 days (IQR 7, 21). Meningitis was suspected in 11% of neonates admitted with clinical sepsis. Uptake for lumbar puncture (LP) or ventricular tap (VT) was low at 4.4% (n = 12), underlining barriers to CSF-based diagnosis in this setting. Late-onset sepsis was associated with only 31.9% of NSM. The chronological age of the neonates at admission (p=0.002) and their duration of hospitalization (p=0.042) were significantly different across the 4 categories of neonates. Prominent sulci, hyperechoic brain lesions, ventriculitis, and lateral ventriculomegaly were the most common abnormal findings on CUS. Overall, neonates with meningitis presented later in age and stayed longer on the ward than those with sepsis: clinical meningitis diagnosis was likely to be made in older neonates and was associated with a shorter duration of hospitalization than CUS-diagnosed meningitis. Overall mortality rate was 2.2%. Mortality (16.7%) was highest amongst those with clinical & CUS diagnosed-NSM. Prevalence of Near-Miss cases of NSM was at least 27.6%. A neonate with clinical diagnosis of NSM was 3.94 times (95% CI 1.80, 8.62; p<0.001) more likely to have abnormal CUS at the time of admission. Percent agreement between the clinical and CUS diagnosis for NSM was 71.1%. Nine (75%) out of the 12 CSF reports was positive for meningitis; and the majority 55.6% (5) of the positive CSF report belonged to the category of neonates with sepsis only. Compared to CSF analysis, sensitivity of clinical diagnosis of NSM was 22.2%; specificity was 33.3%; positive predictive value (PPV) was 50%; negative predictive value (NPV) was 12.5% and likelihood ratio (LR) was 0.33. Whereas, sensitivity of CUS was 44.4%; specificity of CUS was 66.7%; PPV was 80%; NPV was 28.6% and LR was 1.33. Conclusion The CUS was only moderately effective at diagnosing meningitis whereas the presence of positive CSF among neonates with sepsis only within this study, further reaffirms the irreplaceability of CSF analysis in the diagnosis of NSM. Nevertheless, the integration of clinical assessment and CUS findings for diagnosing NSM emerged as possessing greater clinical significance in contexts characterized by limited resources. The systematic adoption of CUS for neonates exhibiting features suggestive of sepsis or meningitis (while exploring measures to improve on uptake of CSF analysis) could enhance the promptness of diagnosis, inform the selection of suitable therapeutic interventions, and potentially mitigate mortality rates and the occurrence of long-term neurological impairments, especially within environments facing resource limitations.

Background: Vitamin D modulates innate and adaptive immunity and has been investigated for preventing pediatric respiratory infections. Objective: To assess the effects of vitamin D supplementation on respiratory tract infections (RTIs), including upper RTIs, lower RTIs/recurrent pneumonia, and hospitalization/clinical severity in children and adolescents. Methods: Systematic review and random-effects meta-analysis of 16 publications, of which 13 contributed to quantitative synthesis. Twenty-four effect estimates were pooled, eight per outcome. The odds ratio (OR) was analyzed on its natural logarithmic scale (logOR), using restricted maximum likelihood (REML) estimation and Knapp-Hartung (KH) adjusted inference. Where necessary, risk ratios (RRs), hazard ratios (HRs), and incidence rate ratios (IRRs) were approximated on the logOR scale. Results: For respiratory infection/upper RTI, pooled logOR was -0.284 (KH-adjusted 95% confidence interval [CI]: -0.678 to 0.110; OR 0.753; p = 0.132; I2 = 97.2%). For lower RTI/recurrent pneumonia, logOR was -0.445 (95% CI: -0.987 to 0.097; OR 0.641; p = 0.093; I2 = 89.5%). For hospitalization/clinical severity, logOR was -0.609 (95% CI: -1.134 to -0.083; OR 0.544; p = 0.029; I2 = 78.3%). Conclusions: Pooled estimates favored supplementation in direction for all three groups, although confidence intervals included the null for the first two. Heterogeneity was substantial, and the results are limited by approximations among effect measures, clinically diverse endpoints, and potentially correlated effects from individual studies.

Background: Vitamin K prophylaxis is universally recommended for newborns to prevent life threatening vitamin K deficiency bleeding. Although not on the immunization schedule, vitamin K prophylaxis is often coadministered with hepatitis B birth dose and erythromycin ophthalmic ointment, and rising hesitancy around vaccines/preventive care may spill over into vitamin K administration. Methods: We conducted a retrospective cohort study using Truveta electronic health record data with linked mother-child dyads. Live births to mothers aged 15-49 from January 1, 2019 through June 30, 2026 were included. Vitamin K administration was defined as documentation on the birth date or following day. Logistic regression assessed sociodemographic predictors of non-receipt, and interrupted time series analysis evaluated changes after January 2026. Results: Among 1,026,375 infants, 995,628 (96.97%) had documented vitamin K administration. Non-receipt increased from an average of 2.1% during 2019-2022 to 4.3% in 2025 and 6.1% in 2026, reaching 8.10% in June 2026. Older maternal age, non-Hispanic or Latino ethnicity, Medicaid or unknown insurance, and year of delivery were associated with greater odds of non-receipt. After January 2026, there was no immediate step change, but the odds of vitamin K receipt declined an additional 10% per month (OR: 0.90; 95% CI, 0.88-0.91). Conclusions: Vitamin K non-receipt increased over the study period and accelerated after January 2026. Because vitamin K recommendations were not changed by the January vaccine schedule, this association may reflect broader impacts to confidence in newborn preventive care. Future studies should examine causal mechanisms, parental decision-making, and associated clinical outcomes.