Roy J. Heyne

Are Outcomes of Extremely Preterm Infants Improving? Impact of Bayley Assessment on Outcomes

OBJECTIVES To compare 18- to 22-month cognitive scores and neurodevelopmental impairment (NDI) in 2 time periods using the National Institute of Child Health and Human Developments Neonatal Research Network assessment of extremely low birth weight infants with the Bayley Scales of Infant Development, Second Edition (Bayley II) in 2006-2007 (period 1) and using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley III), with separate cognitive and language scores, in 2008-2011 (period 2). STUDY DESIGN Scores were compared with bivariate analysis, and regression analyses were run to identify differences in NDI rates. RESULTS Mean Bayley III cognitive scores were 11 points higher than mean Bayley II cognitive scores. The NDI rate was reduced by 70% (from 43% in period 1 to 13% in period 2; P < .0001). Multivariate analyses revealed that Bayley III contributed to a decreased risk of NDI by 5 definitions: cognitive score <70 and <85, cognitive or language score <70; cognitive or motor score <70, and cognitive, language, or motor score <70 (P < .001). CONCLUSION Whether the Bayley III is overestimating cognitive performance or whether it is a more valid assessment of emerging cognitive skills than the Bayley II is uncertain. Because the Bayley III identifies significantly fewer children with disability, it is recommended that all extremely low birth weight infants be offered early intervention services at the time of discharge from the neonatal intensive care unit, and that Bayley scores be interpreted with caution.

Neurodevelopmental Outcomes in the Early CPAP and Pulse Oximetry Trial

BACKGROUND Previous results from our trial of early treatment with continuous positive airway pressure (CPAP) versus early surfactant treatment in infants showed no significant difference in the outcome of death or bronchopulmonary dysplasia. A lower (vs. higher) target range of oxygen saturation was associated with a lower rate of severe retinopathy but higher mortality. We now report longer-term results from our prespecified hypotheses. METHODS Using a 2-by-2 factorial design, we randomly assigned infants born between 24 weeks 0 days and 27 weeks 6 days of gestation to early CPAP with a limited ventilation strategy or early surfactant administration and to lower or higher target ranges of oxygen saturation (85 to 89% or 91 to 95%). The primary composite outcome for the longer-term analysis was death before assessment at 18 to 22 months or neurodevelopmental impairment at 18 to 22 months of corrected age. RESULTS The primary outcome was determined for 1234 of 1316 enrolled infants (93.8%); 990 of the 1058 surviving infants (93.6%) were evaluated at 18 to 22 months of corrected age. Death or neurodevelopmental impairment occurred in 27.9% of the infants in the CPAP group (173 of 621 infants), versus 29.9% of those in the surfactant group (183 of 613) (relative risk, 0.93; 95% confidence interval [CI], 0.78 to 1.10; P=0.38), and in 30.2% of the infants in the lower-oxygen-saturation group (185 of 612), versus 27.5% of those in the higher-oxygen-saturation group (171 of 622) (relative risk, 1.12; 95% CI, 0.94 to 1.32; P=0.21). Mortality was increased with the lower-oxygen-saturation target (22.1%, vs. 18.2% with the higher-oxygen-saturation target; relative risk, 1.25; 95% CI, 1.00 to 1.55; P=0.046). CONCLUSIONS We found no significant differences in the composite outcome of death or neurodevelopmental impairment among extremely premature infants randomly assigned to early CPAP or early surfactant administration and to a lower or higher target range of oxygen saturation. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Heart, Lung, and Blood Institute; SUPPORT ClinicalTrials.gov number, NCT00233324.).

Neuroimaging and Neurodevelopmental Outcome in Extremely Preterm Infants

BACKGROUND: Extremely preterm infants are at risk for neurodevelopmental impairment (NDI). Early cranial ultrasound (CUS) is usual practice, but near-term brain MRI has been reported to better predict outcomes. We prospectively evaluated MRI white matter abnormality (WMA) and cerebellar lesions, and serial CUS adverse findings as predictors of outcomes at 18 to 22 months’ corrected age. METHODS: Early and late CUS, and brain MRI were read by masked central readers, in a large cohort (n = 480) of infants <28 weeks’ gestation surviving to near term in the Neonatal Research Network. Outcomes included NDI or death after neuroimaging, and significant gross motor impairment or death, with NDI defined as cognitive composite score <70, significant gross motor impairment, and severe hearing or visual impairment. Multivariable models evaluated the relative predictive value of neuroimaging while controlling for other factors. RESULTS: Of 480 infants, 15 died and 20 were lost. Increasing severity of WMA and significant cerebellar lesions on MRI were associated with adverse outcomes. Cerebellar lesions were rarely identified by CUS. In full multivariable models, both late CUS and MRI, but not early CUS, remained independently associated with NDI or death (MRI cerebellar lesions: odds ratio, 3.0 [95% confidence interval: 1.3–6.8]; late CUS: odds ratio, 9.8 [95% confidence interval: 2.8–35]), and significant gross motor impairment or death. In models that did not include late CUS, MRI moderate-severe WMA was independently associated with adverse outcomes. CONCLUSIONS: Both late CUS and near-term MRI abnormalities were associated with outcomes, independent of early CUS and other factors, underscoring the relative prognostic value of near-term neuroimaging.

Biomarkers for Severity of Neonatal Hypoxic-Ischemic Encephalopathy and Outcomes in Newborns Receiving Hypothermia Therapy

OBJECTIVE To evaluate serum neuronal and inflammatory biomarkers to determine whether measurements of umbilical cords at birth can stratify severity of hypoxic-ischemic encephalopathy (HIE), whether serial measurements differ with hypothermia-rewarming, and whether biomarkers correlate with neurological outcomes. STUDY DESIGN This is a prospective cohort of inborn term newborns with varying degrees of HIE by neurological assessment. Neuronal glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal hydrolase L1, and inflammatory cytokines were measured in serum from umbilical artery at 6-24, 48, 72, and 78 hours of age. Neurodevelopmental outcomes (Bayley Scales of Infant and Toddler Development-III scales) were performed at 15-18 months. RESULTS Twenty neonates had moderate (n = 17) or severe (n = 3) HIE and received hypothermia; 7 had mild HIE and were not cooled. At birth, serum GFAP and ubiquitin carboxyl-terminal hydrolase L1 increased with the severity of HIE (P < .001), and serial GFAP remained elevated in neonates with moderate to severe HIE. Interleukin (IL)-6, IL-8, and vascular endothelial growth factor were greater at 6-24 hours in moderate to severe vs mild HIE (P < .05). The serial values were unaffected by hypothermia-rewarming. Elevated GFAP, IL-1, IL-6, IL-8, tumor necrosis factor, interferon, and vascular endothelial growth factor at 6-24 hours were associated with abnormal neurological outcomes. CONCLUSIONS The severity of the hypoxic-ischemic injury can be stratified at birth because elevated neuronal biomarkers in cord serum correlated with severity of HIE and outcomes.

Outcome of Extremely Low Birth Weight Infants Who Received Delivery Room Cardiopulmonary Resuscitation

OBJECTIVE To determine whether delivery room cardiopulmonary resuscitation (DR-CPR) independently predicts morbidities and neurodevelopmental impairment (NDI) in extremely low birth weight infants. STUDY DESIGN We conducted a cohort study of infants born with birth weight of 401 to 1000 g and gestational age of 23 to 30 weeks. DR-CPR was defined as chest compressions, medications, or both. Logistic regression was used to determine associations among DR-CPR and morbidities, mortality, and NDI at 18 to 24 months of age (Bayley II mental or psychomotor index <70, cerebral palsy, blindness, or deafness). Data are adjusted ORs with 95% CIs. RESULTS Of 8685 infants, 1333 (15%) received DR-CPR. Infants who received DR-CPR had lower birth weight (708±141 g versus 764±146g, P<.0001) and gestational age (25±2 weeks versus 26±2 weeks, P<.0001). Infants who received DR-CPR had more pneumothoraces (OR, 1.28; 95% CI, 1.48-2.99), grade 3 to 4 intraventricular hemorrhage (OR, 1.47; 95% CI, 1.23-1.74), bronchopulmonary dysplasia (OR, 1.34; 95% CI, 1.13-1.59), death by 12 hours (OR, 3.69; 95% CI, 2.98-4.57), and death by 120 days after birth (OR, 2.22; 95% CI, 1.93-2.57). Rates of NDI in survivors (OR, 1.23; 95% CI, 1.02-1.49) and death or NDI (OR, 1.70; 95% CI, 1.46-1.99) were higher for DR-CPR infants. Only 14% of DR-CPR recipients with 5-minute Apgar score <2 survived without NDI. CONCLUSIONS DR-CPR is a prognostic marker for higher rates of mortality and NDI for extremely low birth weight infants. New DR-CPR strategies are needed for this population.

Respiratory outcomes of the surfactant positive pressure and oximetry randomized trial (SUPPORT).

OBJECTIVE To explore the early childhood pulmonary outcomes of infants who participated in the National Institute of Child Health and Human Developments Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT), using a factorial design that randomized extremely preterm infants to lower vs higher oxygen saturation targets and delivery room continuous positive airway pressure (CPAP) vs intubation/surfactant. STUDY DESIGN The Breathing Outcomes Study, a prospective secondary study to the Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial, assessed respiratory morbidity at 6-month intervals from hospital discharge to 18-22 months corrected age (CA). Two prespecified primary outcomes-wheezing more than twice per week during the worst 2-week period and cough longer than 3 days without a cold-were compared for each randomized intervention. RESULTS One or more interviews were completed for 918 of the 922 eligible infants. The incidences of wheezing and cough were 47.9% and 31.0%, respectively, and did not differ between the study arms of either randomized intervention. Infants randomized to lower vs higher oxygen saturation targets had a similar risk of death or respiratory morbidity (except for croup and treatment with oxygen or diuretics at home). Infants randomized to CPAP vs intubation/surfactant had fewer episodes of wheezing without a cold (28.9% vs 36.5%; P<.05), respiratory illnesses diagnosed by a doctor (47.7% vs 55.2%; P<.05), and physician or emergency room visits for breathing problems (68.0% vs 72.9%; P<.05) by 18-22 months CA. CONCLUSION Treatment with early CPAP rather than intubation/surfactant is associated with less respiratory morbidity by 18-22 months CA. Longitudinal assessment of pulmonary morbidity is necessary to fully evaluate the potential benefits of respiratory interventions for neonates.

Screening for Autism Spectrum Disorders in Extremely Preterm Infants

Background: Extremely preterm (EP) infants screen positive for autism spectrum disorders (ASD) at high rates. However, it is not clear whether this is because of high rates of ASD in EPs or to high rates of false-positive screens for ASD in children with a high rate of underlying neurodevelopmental impairments. Combining a parent questionnaire designed to distinguish developmental delay from ASD with direct observation of infant behavior may more accurately screen for ASD in EPs. Objectives: To determine rates of positive screen for ASD at 18 to 22 months(m) in EPs using 3 screens; to determine factors associated with a positive screen. Methods: Five hundred fifty-four infants born <27 weeks were screened at 18 to 22 m using the Pervasive Developmental Disorders Screening test, second edition Stage 2, and the response to name and response to joint attention items from the Autism Diagnostic Observation Schedule. Infants with severe cerebral palsy, deafness, and blindness were excluded. Associations between positive screen and neonatal/ infant characteristics were determined. Results: Of 554 infants, 113 (20%) had ≥ 1 positive screen. 10% had a positive Pervasive Developmental Disorders Screening test, second edition, 6% response to name, 9% response to joint attention; in only 1 % all 3 screens were positive. Positive screen was associated with male gender, more hospital days, white race, lower maternal education, abnormal behavioral scores, and cognitive/ language delay. Conclusions: The use of 3 screens for ASD in EPs results in higher screen positive rates than use of 1 screen alone. Diagnostic confirmation is needed before true rates of ASD in EPs are known.

Heptavalent pneumococcal conjugate vaccine immunogenicity in very-low-birth-weight, premature infants.

Background: The heptavalent pneumococcal CRM197 conjugate vaccine (PCV-7) has been incompletely studied in very-low-birth-weight (≤1500 g) infants. Objective: To assess PCV-7 immunogenicity in very-low-birth-weight, premature infants. We hypothesized that the frequency of postvaccine antibody concentrations ≥0.15 &mgr;g/mL would vary directly with birth weight. Methods: This was a multicenter observational study. Infants 401 to 1500 g birth weight and <32 0/7 weeks gestation, stratified by birth weight, were enrolled from 9 National Institute of Child Health and Human Development Neonatal Research Network centers. Infants received PCV-7 at 2, 4, and 6 months after birth and had blood drawn 4 to 6 weeks following the third dose. Antibodies against the 7 vaccine serotypes were measured by enzyme-linked immunosorbent assay. Results: Of 369 enrolled infants, 244 completed their primary vaccine series by 8 months and had serum obtained. Subjects were 27.8 ± 2.2 (mean ± standard deviation) weeks gestation and 1008 ± 282 g birth weight. Twenty-six percent had bronchopulmonary dysplasia and 16% had received postnatal glucocorticoids. Infants 1001 to 1500 g birth weight were more likely than those 401 to 1000 g to achieve antibody concentrations ≥0.15 &mgr;g/mL against the least 2 immunogenic serotypes (6B: 96% vs. 85%, P = 0.003 and 23F: 97% vs. 88%, P = 0.009). In multiple logistic regression analysis, lower birth weight, postnatal glucocorticoid use, lower weight at blood draw, and Caucasian race were each independently associated with antibody concentrations <0.35 &mgr;g/mL against serotypes 6B and/or 23F. Conclusions: When compared with larger premature infants, infants weighing ≤1000 g at birth have similar antibody responses to most, but not all, PCV-7 vaccine serotypes.

Predictive Value of Neonatal MRI Showing No or Minor Degrees of Brain Injury After Hypothermia

BACKGROUND Magnetic resonance imaging is a surrogate biomarker for major neurodevelopmental disabilities in survivors of perinatal hypoxic-ischemic encephalopathy because injury to the basal ganglia/thalami is highly predictive of major neuromotor and cognitive problems. Major disabilities and the appearance of neonatal magnetic resonance imaging are improved with therapeutic hypothermia. We evaluated neurodevelopmental outcomes when conventional magnetic resonance imaging showed minimal or no brain injury. METHODS Institutional review board-approved series of 62 infants (≥36 weeks; ≥1800 g; 34 boys/28 girls) cooled for hypoxic-ischemic encephalopathy between 2005 and 2011 who underwent neonatal magnetic resonance imaging and Bayley Scales of Infant and Toddler Development-III at 22 ± 7 months of age. Magnetic resonance imaging at 5-14 (mean 8) days was scored as normal (score = 0), showing focal gray or white matter injury only (score = 1), or basal ganglia/thalamic and/or watershed lesions with or without more extensive hemispheric injury (score = 2). Sensitivity, specificity, and positive and negative predictive values for magnetic resonance scores 0 and 1 and statistical interaction between magnetic resonance imaging score and age at magnetic resonance imaging were determined. RESULTS Magnetic resonance score = 0 was seen in 35/62 patients; 26/35 (74%) were typically developing, seven (20%) had moderate and two (6%) had severe delay. Magnetic resonance score = 1 was seen in 17/62 (27%) patients; 5/17 (29%) were normal, 11/17 (65%) had moderate delay, and 1/17 (6%) had severe neurodevelopmental delay. Of the 52 patients with magnetic resonance scores of 0 and 1, 40% were abnormal. The negative predictive value of a normal magnetic resonance imaging was 74%. For score 1, sensitivity was 95% (confidence interval 63%-83%), specificity 84% (confidence interval 70%-90%), positive predictive value 84% (confidence interval 71%-93%), and negative predictive value 74% (confidence interval 62%-82%). CONCLUSIONS Caution is warranted when prognosticating about neurodevelopmental status in early childhood after hypoxic ischemic encephalopathy with cooling, and longer follow-up studies are needed to determine the prognostic significance of a neonatal magnetic resonance imaging showing no or minor degrees of brain injury.

Immunogenicity of Trivalent Influenza Vaccine in Extremely-Low-Birth-Weight, Premature versus Term Infants

Background: Influenza vaccine immunogenicity in premature infants is incompletely characterized. Objective: To assess the immunogenicity of trivalent, inactivated influenza vaccine (TIV) in extremely low-birth-weight (≤1000 g birth weight) premature (<30 weeks gestation) infants. We hypothesized that geometric mean titers of influenza antibody would be lower in premature than in full-term (FT) (≥37 week) infants. Design/Methods: In this prospective multicenter study, former premature and FT infants who were 6 to 17 months of age received 2 doses of TIV during the 2006–2007 or 2007–2008 influenza seasons. Sera were drawn before dose 1, and 4 to 6 weeks after dose 2. Antibody was measured by hemagglutination inhibition. Results: Over 2 years, 41 premature and 42 FT infants were enrolled; 36 and 33 of these infants, respectively, had postvaccination titers available. Premature infants weighed less (mean, 1.3–1.8 kg difference) at the time of immunization than FT infants. Prevaccination titers did not differ between groups. Premature infants had higher postvaccination antibody geometric mean titers than FT infants to H1 (2006–2007, 1:513 vs. 1:91, P = 0.03; 2007–2008, 1:363 vs. 1:189, P = 0.02) and B/Victoria (2006–2007, 1:51 vs. 1:10, P = 0.02). More premature than FT infants had antibody titers ≥1:32 to B/Victoria (85% vs. 60%, P = 0.04) in 2007–2008. Two (5%) premature and 8 (19%) FT infants had adverse events, primarily fever, within 72 hours after vaccination. No child had medically diagnosed influenza. Conclusions: Former premature infants had antibody responses to 2 TIV doses higher than or equal to those of FT children. Two TIV doses are immunogenic and well tolerated in extremely low-birth-weight, premature infants 6 to 17 months old.