Fractionated Bilirubin Among 252 892 Utah Newborns with and Without Biliary Atresia: A 15-year Historical Birth Cohort Study.

OBJECTIVES: To determine whether neonatal conjugated or direct bilirubin levels were elevated in infants with biliary atresia (BA) and to estimate the number of newborns who would have positive screens in the nursery necessitating repeat testing after discharge. STUDY DESIGN: We used administrative data from a large integrated healthcare network in Utah to identify newborns who had a fractionated bilirubin recorded during birth admission from 2005 through 2019. Elevated conjugated bilirubin was defined as greater than 0.2 mg/dL and direct bilirubin was defined as greater than 0.5 mg/dL (>97.5th percentile for the assays). We performed simulations to estimate the anticipated number of false-positive screens. RESULTS: There were 32 cases of BA and 468 161 live births during the study period (1/14 700). There were 252 892 newborns with fractionated bilirubin assessed, including 26 of those subsequently confirmed to have BA. Conjugated or direct bilirubin was elevated in all 26 infants with BA and an additional 3246 newborns (1.3%) without BA. Simulated data suggest 9-21 per 1000 screened newborns will have an elevated conjugated or direct bilirubin using laboratory-based thresholds for a positive screen. Screening characteristics improved with higher thresholds without increasing false-negative tests. CONCLUSIONS: This study validates the previous findings that conjugated or direct bilirubin are elevated in the newborn period in patients with BA. A higher threshold for conjugated bilirubin improved screening performance. Future studies are warranted to determine the optimal screening test for BA and to assess the effectiveness and cost-effectiveness of implementing such a program.

Treating Center Volume and Congenital Diaphragmatic Hernia Outcomes in California.

OBJECTIVE: To examined outcomes for infants born with congenital diaphragmatic hernias (CDH), according to specific treatment center volume indicators. STUDY DESIGN: A population-based retrospective cohort study was conducted involving neonatal intensive care units in California. Multivariable analysis was used to examine the outcomes of infants with CDH including mortality, total days on ventilation, and respiratory support at discharge. Significant covariables of interest included treatment center surgical and overall neonatal intensive care unit volumes. RESULTS: There were 728 infants in the overall CDH cohort, and 541 infants (74%) in the lower risk subcohort according to a severity-weighted congenital malformation score and never requiring extracorporeal membrane oxygenation. The overall cohort mortality was 28.3% (n = 206), and 19.8% (n = 107) for the subcohort. For the lower risk subcohort, the adjusted odds of mortality were significantly lower at treatment centers with higher CDH repair volume (OR, 0.41; 95% CI, 0.23-0.75; P = .003), ventilator days were significantly lower at centers with higher thoracic surgery volume (OR, 0.56; 9 5% CI, 0.33-0.95; P = .03), and respiratory support at discharge trended lower at centers with higher neonatal intensive care unit admission volumes (OR, 0.51; 9 5% CI, 0.26-1.02; P = .06). CONCLUSIONS: Overall and surgery-specific institutional experience significantly contribute to optimized outcomes for infants with CDH. These data and follow-on studies may help inform the ongoing debate over the optimal care setting and relevant quality indicators for newborn infants with major surgical anomalies.

The Effect of Level of Care on Gastroschisis Outcomes.

OBJECTIVE: To examine the relationship between level of care in neonatal intensive care units (NICUs) and outcomes for newborns with gastroschisis. STUDY DESIGN: A retrospective cohort study was conducted at 130 California Perinatal Quality Care Collaborative NICUs from 2008 to 2014. All gastroschisis births were examined according to American Academy of Pediatrics NICU level of care at the birth hospital. Multivariate analyses examined odds of mortality, duration of mechanical ventilation, and duration of stay. RESULTS: For 1588 newborns with gastroschisis, the adjusted odds of death were higher for those born into a center with a level IIA/B NICU (OR, 6.66; P = .004), a level IIIA NICU (OR, 5.95; P = .008), or a level IIIB NICU (OR, 5.85; P = .002), when compared with level IIIC centers. The odds of having more days on ventilation were significantly higher for births at IIA/B and IIIB centers (OR, 2.05 [P < .001] and OR, 1.91 [P < .001], respectively). The odds of having longer duration of stay were significantly higher at IIA/B and IIIB centers (OR, 1.71 [P < .004]; OR, 1.77 [P < .001]). CONCLUSIONS: NICU level of care was associated with significant disparities in odds of mortality for newborns with gastroschisis.

Acylcarnitine Profiles Reflect Metabolic Vulnerability for Necrotizing Enterocolitis in Newborns Born Premature.

OBJECTIVE: To evaluate the association between newborn acylcarnitine profiles and the subsequent development of necrotizing enterocolitis (NEC) with the use of routinely collected newborn screening data in infants born preterm. STUDY DESIGN: A retrospective cohort study was conducted with the use of discharge records for infants born preterm admitted to neonatal intensive care units in California from 2005 to 2009 who had linked state newborn screening results. A model-development cohort of 94 110 preterm births from 2005 to 2008 was used to develop a risk-stratification model that was then applied to a validation cohort of 22 992 births from 2009. RESULTS: Fourteen acylcarnitine levels and acylcarnitine ratios were associated with increased risk of developing NEC. Each log unit increase in C5 and free carnitine /(C16 + 18:1) was associated with a 78% and a 76% increased risk for developing NEC, respectively (OR 1.78, 95% CI 1.53-2.02, and OR 1.76, 95% CI 1.51-2.06). Six acylcarnitine levels, along with birth weight and total parenteral nutrition, identified 89.8% of newborns with NEC in the model-development cohort (area under the curve 0.898, 95% CI 0.889-0.907) and 90.8% of the newborns with NEC in the validation cohort (area under the curve 0.908, 95% CI 0.901-0.930). CONCLUSIONS: Abnormal fatty acid metabolism was associated with prematurity and the development of NEC. Metabolic profiling through newborn screening may serve as an objective biologic surrogate of risk for the development of disease and thus facilitate disease-prevention strategies.

Urine protein biomarkers for the diagnosis and prognosis of necrotizing enterocolitis in infants.

OBJECTIVES: To test the hypothesis that an exploratory proteomics analysis of urine proteins with subsequent development of validated urine biomarker panels would produce molecular classifiers for both the diagnosis and prognosis of infants with necrotizing enterocolitis (NEC). STUDY DESIGN: Urine samples were collected from 119 premature infants (85 NEC, 17 sepsis, 17 control) at the time of initial clinical concern for disease. The urine from 59 infants was used for candidate biomarker discovery by liquid chromatography/mass spectrometry. The remaining 60 samples were subject to enzyme-linked immunosorbent assay for quantitative biomarker validation. RESULTS: A panel of 7 biomarkers (alpha-2-macroglobulin-like protein 1, cluster of differentiation protein 14, cystatin 3, fibrinogen alpha chain, pigment epithelium-derived factor, retinol binding protein 4, and vasolin) was identified by liquid chromatography/mass spectrometry and subsequently validated by enzyme-linked immunosorbent assay. These proteins were consistently found to be either up- or down-regulated depending on the presence, absence, or severity of disease. Biomarker panel validation resulted in a receiver-operator characteristic area under the curve of 98.2% for NEC vs sepsis and an area under the curve of 98.4% for medical NEC vs surgical NEC. CONCLUSIONS: We identified 7 urine proteins capable of providing highly accurate diagnostic and prognostic information for infants with suspected NEC. This work represents a novel approach to improving the efficiency with which we diagnose early NEC and identify those at risk for developing severe, or surgical, disease.