Limitations of Conventional Magnetic Resonance Imaging as a Predictor of Death or Disability Following Neonatal Hypoxic-Ischemic Encephalopathy in the Late Hypothermia Trial.

OBJECTIVE: To investigate if magnetic resonance imaging (MRI) is an accurate predictor for death or moderate-severe disability at 18-22 months of age among infants with neonatal encephalopathy in a trial of cooling initiated at 6-24 hours. STUDY DESIGN: Subgroup analysis of infants ≥36 weeks of gestation with moderate-severe neonatal encephalopathy randomized at 6-24 postnatal hours to hypothermia or usual care in a multicenter trial of late hypothermia. MRI scans were performed per each center's practice and interpreted by 2 central readers using the Eunice Kennedy Shriver National Institute of Child Health and Human Development injury score (6 levels, normal to hemispheric devastation). Neurodevelopmental outcomes were assessed at 18-22 months of age. RESULTS: Of 168 enrollees, 128 had an interpretable MRI and were seen in follow-up (n = 119) or died (n = 9). MRI findings were predominantly acute injury and did not differ by cooling treatment. At 18-22 months, death or severe disability occurred in 20.3%. No infant had moderate disability. Agreement between central readers was moderate (weighted kappa 0.56, 95% CI 0.45-0.67). The adjusted odds of death or severe disability increased 3.7-fold (95% CI 1.8-7.9) for each increment of injury score. The area under the curve for severe MRI patterns to predict death or severe disability was 0.77 and the positive and negative predictive values were 36% and 100%, respectively. CONCLUSIONS: MRI injury scores were associated with neurodevelopmental outcome at 18-22 months among infants in the Late Hypothermia Trial. However, the results suggest caution when using qualitative interpretations of MRI images to provide prognostic information to families following perinatal hypoxia-ischemia. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00614744.

Determinants of Neonatal Readmission in Healthy Term Infants: Results from a Nested Case-Control Study.

OBJECTIVE: The aim of this study was to estimate the incidence and identify the factors associated with neonatal readmission among healthy term infants. STUDY DESIGN: A nested case-control study with matching was conducted at a large level III perinatal hospital with approximately 8,700 deliveries each year. Each case infant (n = 130) was matched to two control infants (n = 260) on the case infant's date of birth (±7 days) and the mother's maternal age (<20 years, 20-29, 30-39, and >39 years). All infants were selected from a cohort of eligible term, healthy, in-state infants admitted to the newborn unit postdelivery from January 1, 2016 to May 8, 2017. Data were analyzed using hierarchical conditional logistic regression. RESULTS: The incidence of neonatal readmission was 2.2%, and all readmissions occurred within 8.6 days of birth. Earlier gestational age (37 weeks; odds ratio [OR]: 4.11, 95% confidence interval [CI]: 1.79-9.45; 38 weeks OR: 1.29, CI 0.60-2.75; [ref] 39 weeks), jaundice on day two of life (OR: 2.45; CI: 1.40-4.30), maternal group B streptococcus chemoprophylaxis (OR: 2.55; CI: 1.23-5.28 [Ref N/A]) were associated with readmission. Delivery by cesarean section (OR: 0.31, CI: 0.12-0.79) and each milliliter of formula [first three days] (OR: 0.96; CI: 0.993-0.999) were protective. CONCLUSION: Neonatal readmission in healthy term infants may potentially be reduced with identification of modifiable determinants of readmission prior to discharge. Policies to capture the true incidence of neonatal readmissions should include admissions to hospitals other than the birth hospital.

Effect of Therapeutic Hypothermia Initiated After 6 Hours of Age on Death or Disability Among Newborns With Hypoxic-Ischemic Encephalopathy: A Randomized Clinical Trial.

Importance: Hypothermia initiated at less than 6 hours after birth reduces death or disability for infants with hypoxic-ischemic encephalopathy at 36 weeks' or later gestation. To our knowledge, hypothermia trials have not been performed in infants presenting after 6 hours. Objective: To estimate the probability that hypothermia initiated at 6 to 24 hours after birth reduces the risk of death or disability at 18 months among infants with hypoxic-ischemic encephalopathy. Design, Setting, and Participants: A randomized clinical trial was conducted between April 2008 and June 2016 among infants at 36 weeks' or later gestation with moderate or severe hypoxic-ischemic encephalopathy enrolled at 6 to 24 hours after birth. Twenty-one US Neonatal Research Network centers participated. Bayesian analyses were prespecified given the anticipated limited sample size. Interventions: Targeted esophageal temperature was used in 168 infants. Eighty-three hypothermic infants were maintained at 33.5°C (acceptable range, 33°C-34°C) for 96 hours and then rewarmed. Eighty-five noncooled infants were maintained at 37.0°C (acceptable range, 36.5°C-37.3°C). Main Outcomes and Measures: The composite of death or disability (moderate or severe) at 18 to 22 months adjusted for level of encephalopathy and age at randomization. Results: Hypothermic and noncooled infants were term (mean [SD], 39 [2] and 39 [1] weeks' gestation, respectively), and 47 of 83 (57%) and 55 of 85 (65%) were male, respectively. Both groups were acidemic at birth, predominantly transferred to the treating center with moderate encephalopathy, and were randomized at a mean (SD) of 16 (5) and 15 (5) hours for hypothermic and noncooled groups, respectively. The primary outcome occurred in 19 of 78 hypothermic infants (24.4%) and 22 of 79 noncooled infants (27.9%) (absolute difference, 3.5%; 95% CI, -1% to 17%). Bayesian analysis using a neutral prior indicated a 76% posterior probability of reduced death or disability with hypothermia relative to the noncooled group (adjusted posterior risk ratio, 0.86; 95% credible interval, 0.58-1.29). The probability that death or disability in cooled infants was at least 1%, 2%, or 3% less than noncooled infants was 71%, 64%, and 56%, respectively. Conclusions and Relevance: Among term infants with hypoxic-ischemic encephalopathy, hypothermia initiated at 6 to 24 hours after birth compared with noncooling resulted in a 76% probability of any reduction in death or disability, and a 64% probability of at least 2% less death or disability at 18 to 22 months. Hypothermia initiated at 6 to 24 hours after birth may have benefit but there is uncertainty in its effectiveness. Trial Registration: clinicaltrials.gov Identifier: NCT00614744.

The effects of betamethasone on the amplitude integrated EEG of infants born at 34- or 35-weeks gestation.

OBJECTIVE: Assess if maternal betamethasone administration at 34-35 weeks accelerated neonatal amplitude integrated EEG (aEEG) maturation. STUDY DESIGN: Nested, observational cohort in 7 centers participating in the Antenatal Late Preterm Steroid randomized trial. Up to 2 aEEGs were obtained in neonates born from 340-356 weeks gestation before 72 h (aEEG 1) and at 5-7 days (aEEG 2) if hospitalized. Personnel and aEEG central readers were masked to the intervention. The primary outcome was maturation reflected by cycle frequency; secondary outcomes were border voltage, span, and discontinuity. RESULTS: 58 neonates were enrolled (betamethasone, 28, placebo, 30). On aEEG 1, cycle frequency did not differ, but betamethasone exposed infants had a greater lower border voltage and a broader span. On aEEG 2, both groups displayed increases in lower border voltage. CONCLUSIONS: Betamethasone associated changes in lower border voltage support accelerated electrical activity. Further investigation is needed to understand the broader span.

Timing of postnatal steroids for bronchopulmonary dysplasia: association with pulmonary and neurodevelopmental outcomes.

OBJECTIVE: To determine the associations between age at first postnatal corticosteroids (PNS) exposure and risk for severe bronchopulmonary dysplasia (BPD) and neurodevelopmental impairment (NDI). STUDY DESIGN: Cohort study of 951 infants born <27 weeks gestational age at NICHD Neonatal Research Network sites who received PNS between 8 days of life (DOL) and 36 weeks' postmenstrual age was used to produce adjusted odds ratios (aOR). RESULTS: Compared with infants in the reference group (22-28 DOL-lowest rate), aOR for severe BPD was similar for children given PNS between DOL 8 and 49 but higher among infants treated at DOL 50-63 (aOR 1.77, 95% CI 1.03-3.06), and at DOL ≥64 (aOR 3.06, 95% CI 1.44-6.48). The aOR for NDI did not vary significantly by age of PNS exposure. CONCLUSION: For infants at high risk of BPD, initial PNS should be considered prior to 50 DOL for the lowest associated odds of severe BPD.

Identification of Extremely Premature Infants at Low Risk for Early-Onset Sepsis.

BACKGROUND: Premature infants are at high risk of early-onset sepsis (EOS) relative to term infants, and most are administered empirical antibiotics after birth. We aimed to determine if factors evident at birth could be used to identify premature infants at lower risk of EOS. METHODS: Study infants were born at 22 to 28 weeks' gestation in Neonatal Research Network centers from 2006 to 2014. EOS was defined by isolation of pathogenic species from blood or cerebrospinal fluid culture at ≤72 hours age. Infants were hypothesized as "low risk" for EOS when delivered via cesarean delivery, with membrane rupture at delivery, and absence of clinical chorioamnionitis. Frequency of prolonged antibiotics (≥5 days) was compared between low-risk infants and all others. Risks of mortality, EOS, and other morbidities were assessed by using regression models adjusted for center, race, antenatal steroid use, multiple birth, sex, gestation, and birth weight. RESULTS: Of 15 433 infants, 5759 (37%) met low-risk criteria. EOS incidence among infants surviving >12 hours was 29 out of 5640 (0.5%) in the low-risk group versus 209 out of 8422 (2.5%) in the comparison group (adjusted relative risk = 0.24 [95% confidence interval, 0.16-0.36]). Low-risk infants also had significantly lower combined risk of EOS or death ≤12 hours. Prolonged antibiotics were administered to 34% of low-risk infants versus 47% of comparison infants without EOS. CONCLUSIONS: Delivery characteristics of extremely preterm infants can be used to identify those with significantly lower incidence of EOS. Recognition of differential risk may help guide decisions to limit early antibiotic use among approximately one-third of these infants.

Mortality and morbidity of VLBW infants with trisomy 13 or trisomy 18.

OBJECTIVE: Little is known about how very low birth weight (VLBW) affects survival and morbidities among infants with trisomy 13 (T13) or trisomy 18 (T18). We examined the care plans for VLBW infants with T13 or T18 and compared their risks of mortality and neonatal morbidities with VLBW infants with trisomy 21 and VLBW infants without birth defects. METHODS: Infants with birth weight 401 to 1500 g born or cared for at a participating center of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network during the period 1994-2009 were studied. Poisson regression models were used to examine risk of death and neonatal morbidities among infants with T13 or T18. RESULTS: Of 52,262 VLBW infants, 38 (0.07%) had T13 and 128 (0.24%) had T18. Intensity of care in the delivery room varied depending on whether the trisomy was diagnosed before or after birth. The plan for subsequent care for the majority of the infants was to withdraw care or to provide comfort care. Eleven percent of infants with T13 and 9% of infants with T18 survived to hospital discharge. Survivors with T13 or T18 had significantly increased risk of patent ductus arteriosus and respiratory distress syndrome compared with infants without birth defects. No infant with T13 or T18 developed necrotizing enterocolitis. CONCLUSIONS: In this cohort of liveborn VLBW infants with T13 or T18, the timing of trisomy diagnosis affected the plan for care, survival was poor, and death usually occurred early.

Enrollment of extremely low birth weight infants in a clinical research study may not be representative.

BACKGROUND AND OBJECTIVE: The Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT) antenatal consent study demonstrated that mothers of infants enrolled in the SUPPORT trial had significantly different demographics and exposure to antenatal steroids compared with mothers of eligible, but not enrolled infants. The objective of this analysis was to compare the outcomes of bronchopulmonary dysplasia, severe retinopathy of prematurity, severe intraventricular hemorrhage or periventricular leukomalacia (IVH/PVL), death, and death/severe IVH/PVL for infants enrolled in SUPPORT in comparison with eligible, but not enrolled infants. METHODS: Perinatal characteristics and neonatal outcomes were compared for enrolled and eligible but not enrolled infants in bivariate analyses. Models were created to test the effect of enrollment in SUPPORT on outcomes, controlling for perinatal characteristics. RESULTS: There were 1316 infants enrolled in SUPPORT; 3053 infants were eligible, but not enrolled. In unadjusted analyses, enrolled infants had significantly lower rates of death before discharge, severe IVH/PVL, death/severe IVH/PVL (all < 0.001), and bronchopulmonary dysplasia (P = .003) in comparison with eligible, but not enrolled infants. The rate of severe retinopathy of prematurity was not significantly different. After adjustment for perinatal factors, enrollment in the trial was not a significant predictor of any of the tested clinical outcomes. CONCLUSIONS: The results of this analysis demonstrate significant outcome differences between enrolled and eligible but not enrolled infants in a trial using antenatal consent, which were likely due to enrollment bias resulting from the antenatal consent process. Additional research and regulatory review need to be conducted to ensure that large moderate-risk trials that require antenatal consent can be conducted in such a way as to ensure the generalizability of results.

Antenatal consent in the SUPPORT trial: challenges, costs, and representative enrollment.

OBJECTIVES: The purposes of this study were to quantify the time and effort involved in obtaining prenatal consent for the Neonatal Research Network Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT) and to determine whether the enrolled infants were representative of the eligible population. METHODS: Eligible subjects were likely to deliver in the SUPPORT gestational age window (24-27(6/7)] weeks). Data included who approached the subjects for consent, how often they approached, the duration of each contact, whether consent was obtained, and whether subjects were enrolled in the trial. Eligible, nonenrolled infants entered into the Neonatal Research Network Generic Database throughout the period of SUPPORT enrollment were compared with enrolled infants. RESULTS: A total of 2826 women were identified at 18 sites, 2228 were approached for consent, and 1219 (54.7%) agreed. For 76.9% of those approached, <3 visits (mean: 2.0 +/- 1.2 visits) were required to complete the consent process. Of the 659 infants with consent who were delivered within the study window, 611 were enrolled. Mothers who received a neonatal consultation were more likely to give consent (P < .001). The proportion of infants not exposed to steroids was significantly greater in the nonapproached group than in the approached group (20.0% vs 3.4%; P < .0001). CONCLUSION: In a trial that involved preterm infants and required prenatal consent, >5 women were identified as being likely to deliver in the SUPPORT gestational age window for each 1 who delivered an enrolled infant.