Childhood outcomes after hypothermia for neonatal encephalopathy.

BACKGROUND: We previously reported early results of a randomized trial of whole-body hypothermia for neonatal hypoxic-ischemic encephalopathy showing a significant reduction in the rate of death or moderate or severe disability at 18 to 22 months of age. Long-term outcomes are now available. METHODS: In the original trial, we assigned infants with moderate or severe encephalopathy to usual care (the control group) or whole-body cooling to an esophageal temperature of 33.5°C for 72 hours, followed by slow rewarming (the hypothermia group). We evaluated cognitive, attention and executive, and visuospatial function; neurologic outcomes; and physical and psychosocial health among participants at 6 to 7 years of age. The primary outcome of the present analyses was death or an IQ score below 70. RESULTS: Of the 208 trial participants, primary outcome data were available for 190. Of the 97 children in the hypothermia group and the 93 children in the control group, death or an IQ score below 70 occurred in 46 (47%) and 58 (62%), respectively (P=0.06); death occurred in 27 (28%) and 41 (44%) (P=0.04); and death or severe disability occurred in 38 (41%) and 53 (60%) (P=0.03). Other outcome data were available for the 122 surviving children, 70 in the hypothermia group and 52 in the control group. Moderate or severe disability occurred in 24 of 69 children (35%) and 19 of 50 children (38%), respectively (P=0.87). Attention-executive dysfunction occurred in 4% and 13%, respectively, of children receiving hypothermia and those receiving usual care (P=0.19), and visuospatial dysfunction occurred in 4% and 3% (P=0.80). CONCLUSIONS: The rate of the combined end point of death or an IQ score of less than 70 at 6 to 7 years of age was lower among children undergoing whole-body hypothermia than among those undergoing usual care, but the differences were not significant. However, hypothermia resulted in lower death rates and did not increase rates of severe disability among survivors. (Funded by the National Institutes of Health and the Eunice Kennedy Shriver NICHD Neonatal Research Network; ClinicalTrials.gov number, NCT00005772.).

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.).

Improving the Neonatal Research Network annual certification for neurologic examination of the 18-22 month child.

OBJECTIVE: To describe the Neonatal Research Network's efforts to improve the certification process for the Follow-Up Study neurologic exam and to evaluate inter-rater agreement before and after two annual training workshops. STUDY DESIGN: The Neonatal Research Network Follow-Up Study is a multi-center observational study that has examined more than 11 500 infants from 1998-2010 and born ≤26 weeks gestational age at 18-22 months corrected age for neurodevelopmental outcome. The percentages of examiners who agreed with the Gold Standard examiner on 4 neurodevelopmental outcomes on the initial training video and a test video were calculated. Consistency among examiners was assessed with the first-order agreement coefficient statistic. RESULTS: Improvements in agreement among examiners occurred between 2009 and 2010 and between initial training and test. Examiner agreement with the Gold Standard during the initial training was 83%-91% in 2009 and 89%-99% in 2010. Examiner agreement on the workshop test video increased from 2009-2010 with agreement reaching 100% for all four neurodevelopmental outcomes examined in 2010. First-order agreement coefficient values for the four neurodevelopmental outcomes on the training videos ranged from 0.64-0.82 in 2009 and 0.77-0.97 in 2010. CONCLUSIONS: We demonstrate the importance of annual certification and the benefits of evaluation and revision of certification protocols to achieve high levels of confidence in neurodevelopmental study outcomes for multi-center networks.

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 Development's 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.

Growth failure in the preterm infant: can we catch up?

Postnatal growth failure is extremely common in the very low birth weight and extremely low birth weight infant. Recent data from the National Institute of Child and Human Development (NICHD) Neonatal Research Network indicates that 16% of extremely low birth weight infants are small for gestational age at birth, but by 36 weeks corrected age, 89% have growth failure. Follow-up at 18 to 22 months corrected age shows that 40% still have weights, lengths, and head circumferences less than the 10th percentile. Growth failure is associated with an increased risk of poor neurodevelopmental outcome. Inadequate postnatal nutrition is an important factor contributing to growth failure, as most extremely low birth weight infants experience major protein and energy deficits during the neonatal intensive care unit hospitalization, in spite of the fact that nutrition sufficient to support intrauterine growth rates can generally be provided safely. Aggressive nutritional support--parenteral and enteral--is well tolerated in the extremely low birth weight infant and is effective in improving growth. Continued provision of appropriate nutrition (premature formula or fortified human milk) is important throughout the neonatal intensive care unit stay. After discharge, nutrient-enriched postdischarge formula should be continued for approximately 9 months post-term. Exclusively breast-fed infants require additional supplementation/fortification postdischarge as well. Additional trials are needed to address a number of important questions concerning the role of nutrition and growth on ultimate development.

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.

Persistent beneficial effects of breast milk ingested in the neonatal intensive care unit on outcomes of extremely low birth weight infants at 30 months of age.

BACKGROUND: We previously reported beneficial effects of breast milk ingestion by infants with extremely low birth weight in the NICU on developmental outcomes at 18 months' corrected age. The objective of this study was to determine whether these effects of breast milk in infants with extremely low birth weight persisted at 30 months' corrected age. METHODS: Nutrition data, including enteral and parenteral feeds, were prospectively collected, and 30 months' corrected age follow-up assessments were completed on 773 infants with extremely low birth weight who participated in the National Institute of Child Health and Human Development Neonatal Research Network Glutamine Trial. A total of 593 ingested some breast milk during the neonatal hospitalization, and 180 ingested none. Neonatal feeding characteristics and morbidities and 30-month interim history, neurodevelopmental outcomes, and growth parameters were analyzed. Children were divided into quintiles of breast milk volume to evaluate the effects of volume of human milk ingested during the NICU hospitalization. RESULTS: At 30 months, increased ingestion of breast milk was associated with higher Bayley Mental Developmental Index scores, higher Bayley behavior score percentiles for emotional regulation, and fewer rehospitalizations between discharge and 30 months. There were no differences in growth parameters or cerebral palsy. For every 10 mL/kg per day increase in breast milk, the Mental Developmental Index increased by 0.59 points, the Psychomotor Developmental Index by 0.56 points, and the total behavior percentile score by 0.99 points, and the risk of rehospitalization between discharge and 30 months decreased by 5%. CONCLUSIONS: Beneficial effects of ingestion of breast milk in the NICU persist at 30 months' corrected age in this vulnerable extremely low birth weight population. Continued efforts must be made to offer breast milk to all extremely low birth weight infants both in the NICU and after discharge.

Early provision of parenteral amino acids in extremely low birth weight infants: relation to growth and neurodevelopmental outcome.

OBJECTIVE: To determine if postnatal growth failure exerts an adverse effect on subsequent growth and neurodevelopment. STUDY DESIGN: A secondary analysis of 1018 infants who were enrolled in a randomized, clinical trial of glutamine supplementation was performed to determine whether early provision of parenteral amino acids (AA) is associated with better growth and neurodevelopmental outcomes. Infants were stratified by whether they were provided > or =3 g/kg per day of AA at < or =5 days of life (early; n = 182) or not (late; n = 836). RESULTS: At 36 weeks' postmenstrual age, significant differences were found in weight, length, and head circumference in favor of the infants who received early AA; the odds of having weight less than the 10(th) percentile for age was 4-fold higher for infants in the late group. At 18 months' CA, there were no differences in weight, length, or measures of neurodevelopment between the groups; however, male infants in the late group were twice as likely to have head circumference less than the 10(th) percentile. CONCLUSIONS: Early AA were associated with significantly better growth outcomes at 36 weeks' postmenstrual age, and fewer infants who received early AA were found to have suboptimal head growth at 18 months' CA.

Growth in the neonatal intensive care unit influences neurodevelopmental and growth outcomes of extremely low birth weight infants.

OBJECTIVES: The objectives of this study were to assess whether (1) in-hospital growth velocity is predictive of neurodevelopmental and growth outcomes at 18 to 22 months' corrected age among extremely low birth weight (ELBW) infants and (2) in-hospital growth velocity contributes to these outcomes after controlling for confounding demographic and clinical variables. METHODS: Infants 501 to 1000 g birth weight from a multicenter cohort study were divided into quartiles of in-hospital growth velocity rates. Variables considered for the logistic-regression models included gender, race, gestational age, small for gestational age, mother's education, severe intraventricular hemorrhage, periventricular leukomalacia, age at regaining birth weight, necrotizing enterocolitis, late-onset infection, bronchopulmonary dysplasia, postnatal steroid therapy for pulmonary disease, and center. RESULTS: Of the 600 discharged infants, 495 (83%) were evaluated at 18 to 22 months' corrected age. As the rate of weight gain increased between quartile 1 and quartile 4, from 12.0 to 21.2 g/kg per day, the incidence of cerebral palsy, Bayley II Mental Developmental Index (MDI) <70 and Psychomotor Developmental Index (PDI) <70, abnormal neurologic examination, neurodevelopmental impairment, and need for rehospitalization fell significantly. Similar findings were observed as the rate of head circumference growth increased. The in-hospital rate of growth was associated with the likelihood of anthropometric measurements at 18 months' corrected age below the 10th percentile values of the Centers for Disease Control and Prevention 2000 growth curve. Logistic-regression analyses, controlling for potential demographic or clinical cofounders, and adjusted for center, identified a significant relationship between growth velocity and the likelihood of cerebral palsy, MDI and PDI scores of <70, and neurodevelopmental impairment. CONCLUSIONS: These analyses suggest that growth velocity during an ELBW infant's NICU hospitalization exerts a significant, and possibly independent, effect on neurodevelopmental and growth outcomes at 18 to 22 months' corrected age.

Beneficial effects of breast milk in the neonatal intensive care unit on the developmental outcome of extremely low birth weight infants at 18 months of age.

OBJECTIVE: Beneficial effects of breast milk on cognitive skills and behavior ratings have been demonstrated previously in term and very low birth weight infants. Extremely low birth weight infants are known to be at increased risk for developmental and behavior morbidities. The benefits of breast milk that is ingested in the NICU by extremely low birth weight infants on development and behavior have not been evaluated previously. METHODS: Nutrition data including enteral and parenteral feeds were collected prospectively, and follow-up assessments of 1035 extremely low birth weight infants at 18 months' corrected age were completed at 15 sites that were participants in the National Institute of Child Health and Human Development Neonatal Research Network Glutamine Trial between October 14, 1999, and June 25, 2001. Total volume of breast milk feeds (mL/kg per day) during hospitalization was calculated. Neonatal characteristics and morbidities, interim history, and neurodevelopmental and growth outcomes at 18 to 22 months' corrected age were assessed. RESULTS: There were 775 (74.9%) infants in the breast milk and 260 (25.1%) infants in the no breast milk group. Infants in the breast milk group were similar to those in the no breast milk group in every neonatal characteristic and morbidity, including number of days of hospitalization. Mean age of first day of breast milk for the breast milk infants was 9.3 +/- 9 days. Infants in the breast milk group began to ingest non-breast milk formula later (22.8 vs 7.3 days) compared with the non-breast milk group. Age at achieving full enteral feeds was similar between the breast milk and non-breast milk groups (29.0 +/- 18 vs 27.4 +/- 15). Energy intakes of 107.5 kg/day and 105.9 kg/day during the hospitalization did not differ between the breast milk and non-breast milk groups, respectively. At discharge, 30.6% of infants in the breast milk group still were receiving breast milk. Mothers in the breast milk group were significantly more likely to be white (42% vs 27%), be married (50% vs 30%), have a college degree (22% vs 6%), and have private health insurance (34% vs 18%) compared with the no breast milk group. Mothers who were black, had a low household income (< or = dollar 20000), or had higher parity were less likely to provide breast milk feeds. The analysis of outcomes between the any human milk and no human milk groups were adjusted for maternal age, maternal education, marital status, race/ethnicity, and the other standard covariates. Children in the breast milk group were more likely to have a Bayley Mental Development Index > or = 85, higher mean Bayley Psychomotor Development Index, and higher Bayley Behavior Rating Scale percentile scores for orientation/engagement, motor regulation, and total score. There were no differences in the rates of moderate to severe cerebral palsy or blindness or hearing impairment between the 2 study groups. There were no differences in the mean weight (10.4 kg vs 10.4 kg), length (80.5 cm vs 80.5 cm), or head circumference (46.8 cm vs 46.6 cm) for the breast milk and no breast milk groups, respectively, at 18 months. Multivariate analyses, adjusting for confounders, confirmed a significant independent association of breast milk on all 4 primary outcomes: the mean Bayley (Mental Development Index, Psychomotor Development Index, Behavior Rating Scale, and incidence of rehospitalization). For every 10-mL/kg per day increase in breast milk ingestion, the Mental Development Index increased by 0.53 points, the Psychomotor Development Index increased by 0.63 points, the Behavior Rating Scale percentile score increased by 0.82 points, and the likelihood of rehospitalization decreased by 6%. In an effort to identify a threshold effect of breast milk on Bayley Mental Development Index and Psychomotor Development Index scores and Behavior Rating Scale percentile scores, the mean volume of breast milk per kilogram per day during the hospitalization was calculated, and infants in the breast milk group were divided into quintiles of breast milk ingestion adjusted for confounders. Overall, the differences across the feeding quintiles of Mental Development Index and Psychomotor Development Index were significant. There was a 14.0% difference in Behavior Rating Scale scores between the lowest and highest quintiles. For the outcomes (Mental Development Index, Psychomotor Development Index, Behavior Rating Scale, and Rehospitalization <1 year), only the values for the >80th percentile quintile of breast milk feeding were significantly different from the no breast milk values. In our adjusted regression analyses, every 10 mL/kg per day breast milk contributed 0.53 points to the Bayley Mental Development Index; therefore, the impact of breast milk ingestion during the hospitalization for infants in the highest quintile (110 mL/kg per day) on the Bayley Mental Development Index would be 10 x 0.53, or 5.3 points. CONCLUSIONS: An increase of 5 points potentially would optimize outcomes and decrease costs by decreasing the number of very low birth weight children who require special education services. The societal implications of a 5-point potential difference (one third of an SD) in IQ are substantial. The potential long-term benefit of receiving breast milk in the NICU for extremely low birth weight infants may be to optimize cognitive potential and reduce the need for early intervention and special education services.

Neurodevelopmental outcome and growth at 18 to 22 months' corrected age in extremely low birth weight infants treated with early erythropoietin and iron.

BACKGROUND: Clinical trials evaluating the use of erythropoietin (Epo) have demonstrated a limited reduction in transfusions; however, long-term developmental follow-up data are scarce. OBJECTIVE: We compared anthropometric measurements, postdischarge events, need for transfusions, and developmental outcomes at 18 to 22 months' corrected age in extremely low birth weight (ELBW) infants treated with early Epo and supplemental iron therapy with that of placebo/control infants treated with supplemental iron alone. METHODS: The National Institute of Child Health and Human Development Neonatal Research Network completed a randomized, controlled trial of early Epo and iron therapy in preterm infants < or =1250 g. A total of 172 ELBW (< or =1000-g birth weight) infants were enrolled (87 Epo and 85 placebo/control). Of the 72 Epo-treated and 70 placebo/control ELBW infants surviving to discharge, follow-up data (growth, development, rehospitalization, transfusions) at 18 to 22 months' corrected age were collected on 51 of 72 Epo-treated infants (71%) and 51 of 70 placebo/controls (73%) by certified examiners masked to the treatment group. Statistical significance was determined using chi2 analysis. RESULTS: There were no significant differences between treatment groups in weight or length or in the percentage of infants weighing <10th percentile either at the time of discharge or at follow-up, and no difference was found in the mean head circumference between groups. A similar percentage of infants in each group was rehospitalized (38% Epo and 35% placebo/control) for similar reasons. There were no differences between groups with respect to the percentage of infants with Bayley-II Mental Developmental Index <70 (34% Epo and 36% placebo/control), blindness (0% Epo and 2% placebo/control), deafness or hearing loss requiring amplification (2% Epo and 2% placebo/control), moderate to severe cerebral palsy (16% Epo and 18% placebo/control) or the percentage of infants with any of the above-described neurodevelopmental impairments (42% Epo and 44% placebo/control). CONCLUSIONS: Treatment of ELBW infants with early Epo and iron does not significantly influence anthropometric measurements, need for rehospitalization, transfusions after discharge, or developmental outcome at 18 to 22 months' corrected age.

Center differences and outcomes of extremely low birth weight infants.

OBJECTIVE: Previous multicenter studies have shown significant center differences in neonatal characteristics and morbidities. This study evaluated center differences in outcome at 18 to 22 months among extremely low birth weight (ELBW; 401-1000 g) infants after adjusting for demographics and antenatal interventions, and it identified neonatal interventions associated with outcome differences. METHODS: We assessed the outcome of 2478 liveborn infants who were admitted in 1993 and 1994 to the 12 centers of the Neonatal Research Network of the National Institute of Child Health and Human Development; 1483 (60%) infants survived to 18 to 22 months, and 1151 (78%) had comprehensive evaluations. Logistic regression analyses were performed to identify center differences and the association of 4 neonatal interventions--active resuscitation, postnatal steroids, ventilator treatment for < or =27 days, and full enteral feedings < or =24 days--with adverse outcomes (cerebral palsy, low Bayley scores, and neurodevelopmental impairment [NDI]), after adjusting for demographics and antenatal interventions. RESULTS: Using bivariate analyses, significant center differences were identified for mortality, antenatal and postnatal interventions, social and environmental variables, neonatal morbidities, and neurodevelopmental outcomes for the 12 centers. After adjustment for maternal and infant demographics and antenatal interventions, the percentage of ELBW infants who had died or had NDI at 18 to 22 months ranged from 52% to 85%. Active resuscitation and postnatal steroids were associated with increases of NDI of 11.8% and 19.3%, whereas shorter ventilation support and shorter time to achieve full enteral feeds were associated with decreases in NDI of 20.7% and 17.3%, respectively. CONCLUSION: There are large and disturbing differences among centers in outcomes at 18 to 22 months after adjusting for demographic and antenatal interventions. Center differences in postnatal interventions associated with differences in outcome can provide hypotheses for testing in clinical trials to improve outcome.