An Infant with High-Output Heart Failure and Pulmonary Hypertension Resulting from a Giant Cutaneous Hemangioma.

We present the clinical course of an 8-month-old infant with a giant cutaneous hemangioma resulting in high-output heart failure and pulmonary hypertension. The lesion was successfully embolized and excised, with rapid resolution of heart failure and improvement in pulmonary hypertension.

Variability for Age at Successful Extubation in Infants with Congenital Diaphragmatic Hernia.

OBJECTIVE: The objective of this study was to characterize clinical factors associated with successful extubation in infants with congenital diaphragmatic hernia. STUDY DESIGN: Using the Children's Hospitals Neonatal Database, we identified infants with congenital diaphragmatic hernia from 2017 to 2020 at 32 centers. The main outcome was age in days at the time of successful extubation, defined as the patient remaining extubated for 7 consecutive days. Unadjusted Kaplan-Meier and multivariable Cox proportional hazards ratio equations were used to estimate associations between clinical factors and the main outcome. Observations occurred through 180 days after birth. RESULTS: There were 840 eligible neonates with a median gestational age of 38 weeks and birth weight of 3.0 kg. Among survivors (n = 693), the median age at successful extubation was 15 days (interquartile range [IQR]: 8-29 days, 95th percentile: 71 days). For nonsurvivors (n = 147), the median age at death was 21 days (IQR: 11-39 days, 95th percentile: 110 days). Center (adjusted hazards ratio: 0.22-15, P < .01), low birth weight, intrathoracic liver position, congenital heart disease, lower 5-minute Apgar score, lower pH upon admission to Children's Hospitals Neonatal Database center, and use of extracorporeal support were independently associated with older age at successful extubation. Tracheostomy was associated with multiple failed extubations. CONCLUSION: Our findings suggest that infants who have not successfully extubated by about 3 months of age may be candidates for tracheostomy with chronic mechanical ventilation or palliation. The variability of timing of successful extubation among our centers supports the development of practice guidelines after validating clinical criteria.

Predicting Risk of Infection in Infants with Congenital Diaphragmatic Hernia.

OBJECTIVE: To predict incident bloodstream infection and urinary tract infection (UTI) in infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: We conducted a retrospective analysis using the Children's Hospital Neonatal Database during 2010-2016. Infants with CDH admitted at 22 participating regional neonatal intensive care units were included; patients repaired or discharged to home prior to admission/referral were excluded. The primary outcome was death or the occurrence of bloodstream infection or UTI prior to discharge. Factors associated with this outcome were used to develop a multivariable equation using 80% of the cohort. Validation was performed in the remaining 20% of infants. RESULTS: Median gestation and postnatal age at referral in this cohort (n = 1085) were 38 weeks and 3.1 hours, respectively. The primary outcome occurred in 395 patients (36%); and was associated with low birth weight, low Apgar, low admission pH, renal and associated anomalies, patch repair, and extracorporeal membrane oxygenation (P < .001 for all; area under receiver operating curve = 0.824; goodness of fit χ2 = 0.52). After omitting death from the outcome measure, admission pH, patch repair of CDH, and duration of central line placement were significantly associated with incident bloodstream infection or UTI. CONCLUSIONS: Infants with CDH are at high risk of infection which was predicted by clinical factors. Early identification and low threshold for sepsis evaluations in high-risk infants may attenuate acquisition and the consequences of these infections.

The Impact of Pulmonary Hypertension in Preterm Infants with Severe Bronchopulmonary Dysplasia through 1 Year.

OBJECTIVES: To assess the effect of pulmonary hypertension on neonatal intensive care unit mortality and hospital readmission through 1 year of corrected age in a large multicenter cohort of infants with severe bronchopulmonary dysplasia. STUDY DESIGN: This was a multicenter, retrospective cohort study of 1677 infants born <32 weeks of gestation with severe bronchopulmonary dysplasia enrolled in the Children's Hospital Neonatal Consortium with records linked to the Pediatric Health Information System. RESULTS: Pulmonary hypertension occurred in 370 out of 1677 (22%) infants. During the neonatal admission, pulmonary hypertension was associated with mortality (OR 3.15, 95% CI 2.10-4.73, P < .001), ventilator support at 36 weeks of postmenstrual age (60% vs 40%, P < .001), duration of ventilation (72 IQR 30-124 vs 41 IQR 17-74 days, P < .001), and higher respiratory severity score (3.6 IQR 0.4-7.0 vs 0.8 IQR 0.3-3.3, P < .001). At discharge, pulmonary hypertension was associated with tracheostomy (27% vs 9%, P < .001), supplemental oxygen use (84% vs 61%, P < .001), and tube feeds (80% vs 46%, P < .001). Through 1 year of corrected age, pulmonary hypertension was associated with increased frequency of readmission (incidence rate ratio [IRR] = 1.38, 95% CI 1.18-1.63, P < .001). CONCLUSIONS: Infants with severe bronchopulmonary dysplasia-associated pulmonary hypertension have increased morbidity and mortality through 1 year of corrected age. This highlights the need for improved diagnostic practices and prospective studies evaluating treatments for this high-risk population.

Cord Blood Biomarkers of Placental Maternal Vascular Underperfusion Predict Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension.

OBJECTIVE: To assess whether cord blood biomarkers associated with placental maternal vascular underperfusion (MVU) are predictive of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH). STUDY DESIGN: Premature infants enrolled in a longitudinal cohort study were randomly sampled from 4 gestational age strata (n?=?190, range 23-36 weeks). Fifteen factors from a human angiogenesis panel were measured in cord blood using multiplex immunoassay. Multivariate linear regression was used to compare biomarker levels according to placental histologic MVU, taking into account acute/chronic inflammation and fetal vascular pathology. Biomarkers associated with MVU were further evaluated in the subgroup of extremely low gestational age infants (gestational age ? 28 weeks; n?=?48), and measured by enzyme-linked immunoassay in an additional 39 infants to determine associations with BPD (defined using the National Institutes of Health workshop criteria) and PH (identified by echocardiogram at 36 weeks of gestation). RESULTS: Cord blood placental growth factor (PIGF), granulocyte-colony stimulating factor (G-CSF), and vascular endothelial growth factor-A were decreased with MVU (P?

The Randomized, Controlled Trial of Late Surfactant: Effects on Respiratory Outcomes at 1-Year Corrected Age.

OBJECTIVE: To determine the effects of late surfactant on respiratory outcomes determined at 1-year corrected age in the Trial of Late Surfactant (TOLSURF), which randomized newborns of extremely low gestational age (≤28 weeks' gestational age) ventilated at 7-14 days to late surfactant and inhaled nitric oxide vs inhaled nitric oxide-alone (control). STUDY DESIGN: Caregivers were surveyed in a double-blinded manner at 3, 6, 9, and 12 months' corrected age to collect information on respiratory resource use (infant medication use, home support, and hospitalization). Infants were classified for composite outcomes of pulmonary morbidity (no PM, determined in infants with no reported respiratory resource use) and persistent PM (determined in infants with any resource use in ≥3 surveys). RESULTS: Infants (n = 450, late surfactant n = 217, control n = 233) were 25.3 ± 1.2 weeks' gestation and 713 ± 164 g at birth. In the late surfactant group, fewer infants received home respiratory support than in the control group (35.8% vs 52.9%, relative benefit [RB] 1.28 [95% CI 1.07-1.55]). There was no benefit of late surfactant for No PM vs PM (RB 1.27; 95% CI 0.89-1.81) or no persistent PM vs persistent PM (RB 1.01; 95% CI 0.87-1.17). After adjustment for imbalances in baseline characteristics, relative benefit of late surfactant treatment increased: RB 1.40 (95% CI 0.89-1.80) for no PM and RB 1.24 (95% CI 1.08-1.42) for no persistent PM. CONCLUSION: Treatment of newborns of extremely low gestational age with late surfactant in combination with inhaled nitric oxide decreased use of home respiratory support and may decrease persistent pulmonary morbidity. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01022580.

Randomized Trial of Late Surfactant Treatment in Ventilated Preterm Infants Receiving Inhaled Nitric Oxide.

OBJECTIVE: To assess whether late surfactant treatment in extremely low gestational age (GA) newborn infants requiring ventilation at 7-14 days, who often have surfactant deficiency and dysfunction, safely improves survival without bronchopulmonary dysplasia (BPD). STUDY DESIGN: Extremely low GA newborn infants (GA ≤28 0/7 weeks) who required mechanical ventilation at 7-14 days were enrolled in a randomized, masked controlled trial at 25 US centers. All infants received inhaled nitric oxide and either surfactant (calfactant/Infasurf) or sham instillation every 1-3 days to a maximum of 5 doses while intubated. The primary outcome was survival at 36 weeks postmenstrual age (PMA) without BPD, as evaluated by physiological oxygen/flow reduction. RESULTS: A total of 511 infants were enrolled between January 2010 and September 2013. There were no differences between the treated and control groups in mean birth weight (701 ± 164 g), GA (25.2 ± 1.2 weeks), percentage born at GA <26 weeks (70.6%), race, sex, severity of lung disease at enrollment, or comorbidities of prematurity. Survival without BPD did not differ between the treated and control groups at 36 weeks PMA (31.3% vs 31.7%; relative benefit, 0.98; 95% CI, 0.75-1.28; P = .89) or 40 weeks PMA (58.7% vs 54.1%; relative benefit, 1.08; 95% CI, 0.92-1.27; P = .33). There were no between-group differences in serious adverse events, comorbidities of prematurity, or severity of lung disease to 36 weeks. CONCLUSION: Late treatment with up to 5 doses of surfactant in ventilated premature infants receiving inhaled nitric oxide was well tolerated, but did not improve survival without BPD at 36 or 40 weeks. Pulmonary and neurodevelopmental assessments are ongoing. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01022580.

Short-term outcomes and medical and surgical interventions in infants with congenital diaphragmatic hernia.

OBJECTIVE: The aim of this study is to characterize medical and surgical therapies and short-term outcomes in infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: Retrospective analysis of CDH infants admitted to 27 children's hospitals submitting data to Children's Hospital Neonatal Database (CHND) from 2010 to 2013, stratified by gestational age, birth weight, and survival. RESULTS: A total of 572 infants were identified, 508 (89%) born ≥ 34 weeks' gestation and ≥ 2 kg. More mature infants had higher APGAR scores, shorter duration of mechanical ventilation, and were more likely to receive extracorporeal membrane oxygenation (ECMO). Overall, mortality for the cohort was 29%, with mortality lower in infants born ≥ 34 weeks' gestation and ≥ 2 kg (26 vs. 50%, p < 0.01). Nonsurvivors were more likely to receive treatment with high-frequency oscillatory ventilation (HFOV), vasopressors, pulmonary vasodilators, and ECMO, and to have associated major congenital anomalies than survivors. In hospital morbidity and complications were relatively uncommon among survivors. CONCLUSION: Infants with CDH have a high risk of morbidity and mortality, and for preterm infants with CDH those risks are amplified. Patterns of respiratory and circulatory support appeared to be different for survivors. In addition to established data registries, this consortium of regional neonatal intensive care units provides a new collaborative effort to describe short-term outcomes for infants referred with CDH.

Enteral feeding during indomethacin and ibuprofen treatment of a patent ductus arteriosus.

OBJECTIVE: To test the hypothesis that infants who are just being introduced to enteral feedings will advance to full enteral nutrition at a faster rate if they receive "trophic" (15 mL/kg/d) enteral feedings while receiving indomethacin or ibuprofen treatment for patent ductus arteriosus. STUDY DESIGN: Infants were eligible for the study if they were 23(1/7)-30(6/7) weeks' gestation, weighed 401-1250 g at birth, received maximum enteral volumes ≤60 mL/kg/d, and were about to be treated with indomethacin or ibuprofen. A standardized "feeding advance regimen" and guidelines for managing feeding intolerance were followed at each site (N = 13). RESULTS: Infants (N = 177, 26.3 ± 1.9 weeks' mean ± SD gestation) were randomized at 6.5 ± 3.9 days to receive "trophic" feeds ("feeding" group, n = 81: indomethacin 80%, ibuprofen 20%) or no feeds ("fasting [nil per os]" group, n = 96: indomethacin 75%, ibuprofen 25%) during the drug administration period. Maximum daily enteral volumes before study entry were 14 ± 15 mL/kg/d. After drug treatment, infants randomized to the "feeding" arm required fewer days to reach the study's feeding volume end point (120 mL/kg/d). Although the enteral feeding end point was reached at an earlier postnatal age, the age at which central venous lines were removed did not differ between the 2 groups. There were no differences between the 2 groups in the incidence of infection, necrotizing enterocolitis, spontaneous intestinal perforation, or other neonatal morbidities. CONCLUSION: Infants required less time to reach the feeding volume end point if they were given "trophic" enteral feedings when they received indomethacin or ibuprofen treatments.

The association between pulmonary vascular disease and respiratory improvement in infants with type I severe bronchopulmonary dysplasia.

OBJECTIVE: To describe the association between echocardiographic measures of pulmonary vascular disease and time to respiratory improvement among infants with Type I severe bronchopulmonary dysplasia (sBPD). STUDY DESIGN: We measured the pulmonary artery acceleration time indexed to the right ventricular ejection time (PAAT/RVET) and right ventricular free wall longitudinal strain (RVFWLS) at 34-41 weeks' postmenstrual age. Cox-proportional hazards models were used to estimate the relationship between the PAAT/RVET, RVFWLS, and the outcome: days from 36 weeks' postmenstrual age to room-air or discharge with oxygen (≤0.5 L/min). RESULT: For 102 infants, the mean PAAT/RVET and RVFWLS were 0.27 ± 0.06 and -22.63 ± 4.23%. An abnormal measurement was associated with an increased time to achieve the outcome (PAAT/RVET: 51v24, p < 0.0001; RVFWLS; 62v38, p = 0.0006). A normal PAAT/RVET was independently associated with a shorter time to outcome (aHR = 2.04, 1.11-3.76, p = 0.02). CONCLUSION: The PAAT/RVET may aid in anticipating timing of discharge in patients with type I severe BPD.

Predicting treatment of pulmonary hypertension at discharge in infants with congenital diaphragmatic hernia.

OBJECTIVE: To predict pulmonary hypertension (PH) therapy at discharge in a large multicenter cohort of infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: Six-year linked records from Children's Hospitals Neonatal Database and Pediatric Health Information System were used; patients whose diaphragmatic hernia was repaired before admission or referral, who were previously home before admission or referral, and non-survivors were excluded. The primary outcome was the use of PH medications at discharge and the secondary outcome was an inter-center variation of therapies during inpatient utilization. Clinical factors were used to develop a multivariable equation randomly applied to 80% cohort; validated in the remaining 20% infants. RESULTS: A total of 831 infants with CDH from 23 centers were analyzed. Overall, 11.6% of survivors were discharged on PH medication. Center, duration of mechanical ventilation, and duration of inhaled nitric oxide were associated with the use of PH medication at discharge. This model performed well in the validation cohort area under the receiver operating characteristic curve of 0.9, goodness-of-fit χ2, p = 0.17. CONCLUSIONS: Clinical variables can predict the need for long-term PH medication after NICU hospitalization in surviving infants with CDH. This information may be useful to educate families and guide the development of clinical guidelines.

A comparison of newer classifications of bronchopulmonary dysplasia: findings from the Children's Hospitals Neonatal Consortium Severe BPD Group.

OBJECTIVE: To compare three bronchopulmonary dysplasia (BPD) definitions against hospital outcomes in a referral-based population. STUDY DESIGN: Data from the Children's Hospitals Neonatal Consortium were classified by 2018 NICHD, 2019 NRN, and Canadian Neonatal Network (CNN) BPD definitions. Multivariable models evaluated the associations between BPD severity and death, tracheostomy, or length of stay, relative to No BPD references. RESULTS: Mortality was highest in 2019 NRN Grade 3 infants (aOR 225), followed by 2018 NICHD Grade 3 (aOR 145). Infants with lower BPD grades rarely died (<1%), but Grade 2 infants had aOR 7-21-fold higher for death and 23-56-fold higher for tracheostomy. CONCLUSIONS: Definitions with 3 BPD grades had better discrimination and Grade 3 2019 NRN had the strongest association with outcomes. No/Grade 1 infants rarely had severe outcomes, but Grade 2 infants were at risk. These data may be useful for counseling families and determining therapies for infants with BPD.

Qualitative indications for tracheostomy and chronic mechanical ventilation in patients with severe bronchopulmonary dysplasia.

BACKGROUND: The decision to pursue chronic mechanical ventilation involves a complex mix of clinical and social considerations. Understanding the medical indications to pursue tracheostomy would reduce the ambiguity for both providers and families and facilitate focus on appropriate clinical goals. OBJECTIVE: To describe potential indications to pursue tracheostomy and chronic mechanical ventilation in infants with severe BPD (sBPD). STUDY DESIGN: We surveyed centers participating in the Children's Hospitals Neonatal Consortium to describe their approach to proceed with tracheostomy in infants with sBPD. We requested a single representative response per institution. Question types were fixed form and free text responses. RESULTS: The response rate was high (31/34, 91%). Tracheostomy was strongly considered when: airway malacia was present, PCO2 ≥ 76-85 mmHg, FiO2 ≥ 0.60, PEEP ≥ 9-11 cm H2O, respiratory rate ≥ 61-70 breaths/min, PMA ≥ 44 weeks, and weight <10th %ile at 44 weeks PMA. CONCLUSIONS: Understanding the range of indications utilized by high level NICUs around the country to pursue a tracheostomy in an infant with sBPD is one step toward standardizing consensus indications for tracheostomy in the future.

Treatment of pulmonary hypertension during initial hospitalization in a multicenter cohort of infants with congenital diaphragmatic hernia (CDH).

OBJECTIVE: Describe inpatient pulmonary hypertension (PH) treatment and factors associated with therapy at discharge in a multicenter cohort of infants with CDH. METHODS: Six years linked records from Children's Hospitals Neonatal Database and Pediatric Health Information System were used to describe associations between prenatal/perinatal factors, clinical outcomes, echocardiographic findings and PH medications (PHM), during hospitalization and at discharge. RESULTS: Of 1106 CDH infants from 23 centers, 62.8% of infants received PHM, and 11.6% of survivors were discharged on PHM. Survivors discharged on PHM more frequently had intrathoracic liver, small for gestational age, and low 5 min APGARs compared with those discharged without PHM (p < 0.0001). Nearly one-third of infants discharged without PHM had PH on last inpatient echo. CONCLUSIONS: PH medication use is common in CDH. Identification of infants at risk for persistent PH may impact ongoing management. Post-discharge follow-up of all CDH infants with echocardiographic evidence of PH is warranted.

Utility of echocardiography in predicting mortality in infants with severe bronchopulmonary dysplasia.

OBJECTIVE: To determine the relationship between interventricular septal position (SP) and right ventricular systolic pressure (RVSP) and mortality in infants with severe BPD (sBPD). STUDY DESIGN: Infants with sBPD in the Children's Hospitals Neonatal Database who had echocardiograms 34-44 weeks' postmenstrual age (PMA) were included. SP and RVSP were categorized normal, abnormal (flattened/bowed SP or RVSP > 40 mmHg) or missing. RESULTS: Of 1157 infants, 115 infants (10%) died. Abnormal SP or RVSP increased mortality (SP 19% vs. 8% normal/missing, RVSP 20% vs. 9% normal/missing, both p < 0.01) in unadjusted and multivariable models, adjusted for significant covariates (SP OR 1.9, 95% CI 1.2-3.0; RVSP OR 2.2, 95% CI 1.1-4.7). Abnormal parameters had high specificity (SP 82%; RVSP 94%), and negative predictive value (SP 94%, NPV 91%) for mortality. CONCLUSIONS: Abnormal SP or RVSP is independently associated with mortality in sBPD infants. Negative predictive values distinguish infants most likely to survive.

Milrinone enhances relaxation to prostacyclin and iloprost in pulmonary arteries isolated from lambs with persistent pulmonary hypertension of the newborn.

UNLABELLED: Prostacyclin is a pulmonary vasodilator and is produced by prostacyclin synthase and stimulates adenylate cyclase (AC) via the prostacyclin receptor (IP) to produce cAMP. Forskolin is a direct stimulant of AC. Phosphodiesterase 3 hydrolyzes cAMP and is inhibited by milrinone. OBJECTIVE: To characterize the prostacyclin-AC-cAMP pathway in the ovine ductal ligation model of persistent pulmonary hypertension of the newborn (PPHN). SETTING: University-based laboratory animal facility. SUBJECTS: Lambs delivered to time-dated pregnant ewes. INTERVENTIONS: Fifth generation pulmonary arteries (PA) and lung parenchyma were isolated from control fetal lambs (n = 8) and fetal lambs with PPHN induced by antenatal ductal ligation (n = 9). We studied relaxation responses to various agonists (milrinone, forskolin, prostacyclin, and iloprost, a prostacyclin analog) that increase cAMP in PA after half-maximal constriction with norepinephrine and pretreatment with propranolol +/- indomethacin. Lung protein levels of prostacyclin synthase, IP, AC2, and phosphodiesterase 3A were analyzed by Western blot and cAMP by enzyme-linked immunoassay. MAIN RESULTS: Milrinone relaxed control and PPHN PA and pretreatment with indomethacin significantly impaired this response. Relaxation to milrinone, prostacyclin, and iloprost were significantly impaired in PA from PPHN lambs. Pretreatment with milrinone markedly enhanced relaxation to prostacyclin and iloprost in PPHN PA, similar to relaxation in control PA. Relaxation to forskolin was similar in control and PPHN PAs indicating normal AC activity. Protein levels of prostacyclin synthase and IP were decreased in PPHN lungs compared with control, but AC2, cAMP, and phosphodiesterase 3A remained unchanged. CONCLUSIONS: Prostacyclin and iloprost are dilators of PAs from PPHN lambs and their effect is enhanced by milrinone. This combination therapy may be an effective strategy in the management of patients with PPHN.

Extracorporeal membrane oxygenation and bloodstream infection in congenital diaphragmatic hernia.

OBJECTIVE: To characterize the risk of bloodstream (BSI) and urinary tract infection (UTI) and describe antibiotic use in infants with congenital diaphragmatic hernia (CDH) requiring extracorporeal membrane oxygenation (ECMO). STUDY DESIGN: The Children's Hospitals Neonatal Database was queried for infants with CDH and ECMO treatment from 2010 to 2016. The outcomes included BSI, UTI, and antimicrobial medication. Member institutions completed a survey on infection practices. RESULT: Eighteen of the 338 patients identified (5.3%) had ≥1 BSI during their ECMO course. The likelihood of BSI increased with time: 1.2/1000 ECMO days; 0.6% (2/315) in the first week and rising to 14.6/1000; 8.6% (5/58) after 21 days (p = 0.002). More than 95% of patients received antibiotics each week on ECMO. CONCLUSIONS: Confirmed BSI is rare in infants with CDH treated with ECMO in the first week, but increases with the duration of ECMO. Use of antibiotics was extensive and did not correspond to infection frequency.

Inhaled NO in the experimental setting.

Nitric oxide, a gas molecule, is a unique pharmaceutical agent that can be inhaled and thus delivered directly to the lung. More than a decade of intensive laboratory and clinical investigation has culminated in the current role for inhaled NO as the only selective pulmonary vasodilator for the treatment of persistent pulmonary hypertension of the newborn (PPHN). Not surprisingly, this potent and successful therapy continues to be studied intensively to better define its mechanism of action and role in PPHN treatment. In addition, there remains intense interest in possible new applications for newborns, as well as strategies that may enhance its efficacy. This review describes several areas of current research on amplification of NO signaling in the neonatal pulmonary vasculature, and reviews our current knowledge about the role of iNO in other conditions such as congenital diaphragmatic hernia and congenital heart disease. In addition, laboratory and clinical studies addressing a potential role for iNO as a therapeutic modality for the preterm infant are reviewed.

Acquired Infection and Antimicrobial Utilization During Initial NICU Hospitalization in Infants With Congenital Diaphragmatic Hernia.

BACKGROUND: In addition to substantial medical and surgical intervention, neonates with congenital diaphragmatic hernia often have concurrent concerns for acquired infection. However, few studies focus on infection and corresponding antimicrobial utilization in this population. METHODS: The Children's Hospital Neonatal Database was queried for congenital diaphragmatic hernia infants hospitalized from January 2010 to February 2016. Patient charts were linked to the Pediatric Health Information Systems database. Descriptive clinical data including delivery history, cultures sent, diagnosed infection, antimicrobial use and outcomes were reported. RESULTS: A total of 1085 unique patients were identified after data linkages; 275 (25.3%) were born at <37 weeks' gestation. Bacteremia at delivery (2/1085) and in the first 7 days of life (8/1085) was less common than later infection, but 976 patients (89.9%) were treated with antibiotics. Median number of days on antibiotics was 6 [3,11] for those without a documented infection and 21 [13,36] for those with positive cultures. Incidence of urinary tract infection, bacteremia and pneumonia increased significantly over time and was most common after 28 days. Antibiotic use, conversely, decreased over time (92% of infants in week 1 to 44% in week 4 and beyond). CONCLUSIONS: Although culture positivity increased with age, risk of these selected infections was relatively low for a population in neonatal intensive care unit. An important mismatch is observed between culture negativity and high rates of antibiotic utilization. These data identify opportunities for antibiotic stewardship quality improvement programs.