Association between small-for-gestational age and neurocognitive impairment at two years of corrected age among infants born at preterm gestational ages: a cohort study.

OBJECTIVE: To investigate the association between small-for-gestational age (SGA) and neurocognitive impairment at 2 years of corrected age among infants born at preterm gestational ages. STUDY DESIGN: A secondary analysis of a prospectively conducted NICHD/Maternal-Fetal Medicine Units BEAM trial. Non-anomalous pregnancies delivered before 37 weeks of gestation were included in the analysis. Neurocognitive outcomes at 2 years of corrected age were compared between infants who were SGA (<10% for gestational age) and those appropriately grown (AGA). The primary outcome was a severe or moderate neurocognitive impairment at 2 years of corrected age among survivors, defined as either mental (MDI) or psychomotor (PDI) developmental index score <70 for severe and <85 for moderate impairment. RESULTS: Of 2299 preterm neonates 67 (3%) were SGA. SGA infants were more often twin pregnancies (31% vs 17%, P=0.003) and delivered more often by cesarean section (63% vs 40%, P<0.001) at similar gestational ages (30.0±2.6 vs 29.5±2.8 weeks, P=0.11). At 2 years of corrected age, SGA and AGA survivors had similar rates of neurocognitive impairment (MDI <70: 18% vs 18%, P=1.0; MDI <85: 44% vs 46%, P=0.96; PDI <70: 20% vs 15%, P=0.51; PDI <85: 40% vs 34%, P=0.48). CONCLUSION: In this cohort, SGA at preterm gestational ages was associated with similar rates of neurocognitive impairment at two years of corrected age among surviving infants.

Utility of third trimester sonographic measurements for predicting SGA in cases of fetal gastroschisis.

OBJECTIVE: To assess the accuracy of different sonographic estimated fetal weight (EFW) cutoffs, and combinations of EFW and biometric measurements for predicting small for gestational age (SGA) in fetal gastroschisis. STUDY DESIGN: Gastroschisis cases from two centers were included. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated for different EFW cutoffs, as well as EFW and biometric measurement combinations. RESULTS: Seventy gastroschisis cases were analyzed. An EFW<10% had 94% sensitivity, 43% specificity, 33% PPV and 96% NPV for SGA at delivery. Using an EFW cutoff of <5% improved the specificity to 63% and PPV to 41%, but decreased the sensitivity to 88%. Combining an abdominal circumference (AC) or femur length (FL) z-score less than -2 with the total EFW improved the specificity and PPV but decreased the sensitivity. CONCLUSION: A combination of a small AC or FL along with EFW increases the specificity and PPV, but decreases the sensitivity of predicting SGA.

Do currently recommended Bayley-III cutoffs overestimate motor impairment in infants born <27 weeks gestation?

OBJECTIVE: To determine whether a Bayley-III motor composite score of 85 may overestimate moderate-severe motor impairment by analyzing Bayley-III motor components and developing cut-point scores for each. STUDY DESIGN: Retrospective study of 1183 children born <27 weeks gestation at NICHD Neonatal Research Network centers and evaluated at 18-22 months corrected age. Gross Motor Function Classification System determined gross motor impairment. Statistical analyses included linear and logistic regression and sensitivity/specificity. RESULTS: Bayley-III motor composite scores were strong indicators of gross/fine motor impairment. A motor composite cut-point of 73 markedly improved the specificity for identifying gross and/or fine motor impairment (94% compared with a specificity of 76% for the proposed new cut-point of 85). A Fine Motor Scaled Score <3 differentiated mild from moderate-severe fine motor impairment. CONCLUSIONS: This study indicates that a Bayley-III motor composite score of 85 may overestimate impairment. Further studies are needed employing term controls and longer follow-up.

Serial aEEG recordings in a cohort of extremely preterm infants: feasibility and safety.

OBJECTIVE: Amplitude-integrated electroencephalography (aEEG) monitoring is increasing in the neonatal population, but the safety and feasibility of performing aEEG in extremely preterm infants have not been systematically evaluated. STUDY DESIGN: Inborn infants 23(0/7) to 28(6/7) weeks gestation or birth weight 401 to 1000 g were eligible. Serial, 6-h aEEG recordings were obtained from first week of life until 36 weeks postmenstrual age. Adverse events were documented, and surveys evaluated the impact of the aEEGs on routine care. Success of performing aEEGs according to protocol and aEEG quality were assessed. RESULT: A total of 102 infants were enrolled, with 755 recordings performed. 83% of recordings were performed according to schedule, and 96% were without adverse event. Bedside nurses reported no interference with routine care for 89% of recordings. 92% of recordings had acceptable signal quality. CONCLUSION: Serial aEEG monitoring is safe in preterm infants, with few adverse events and general acceptance by nursing staff.

Outcomes of extremely preterm infants following severe intracranial hemorrhage.

OBJECTIVE: Severe intracranial hemorrhage (ICH) is an important prognostic variable in extremely preterm (EPT) infants. We examined imaging and clinical variables that predict outcomes in EPT infants with severe ICH. STUDY DESIGN: Retrospective analysis of 353 EPT infants with severe ICH. Outcomes were compared by examining: (i) unilateral vs bilateral ICH; and (ii) presence vs absence of hemorrhagic parenchymal infarction (HPI). Regression analyses identified variables associated with death or neurodevelopmental impairment (NDI). RESULT: Bilateral ICH and HPI had higher rates of adverse outcomes and were independently associated with death/NDI. HPI was the most important variable for infants of lower birth weight, and bilateral ICH for larger infants. For infants surviving to 36 weeks, shunt placement was most associated with death/NDI. CONCLUSION: Bilateral ICH and the presence of HPI in EPT infants with severe ICH are associated with death/NDI, though the importance depends on birth weight and survival to 36 weeks.

Neurodevelopmental outcomes of extremely low birth weight infants with spontaneous intestinal perforation or surgical necrotizing enterocolitis.

OBJECTIVE: To determine if extremely low birth weight infants with surgical necrotizing enterocolitis have a higher risk of death or neurodevelopmental impairment and neurodevelopmental impairment among survivors (secondary outcome) at 18-22 months corrected age compared with infants with spontaneous intestinal perforation and infants without necrotizing enterocolitis or spontaneous intestinal perforation. STUDY DESIGN: Retrospective analysis of the Neonatal Research Network very low birth weight registry, evaluating extremely low birth weight infants born between 2000 and 2005. The study infants were designated into three groups: (1) spontaneous intestinal perforation without necrotizing enterocolitis; (2) surgical necrotizing enterocolitis (Bell's stage III); and (3) neither spontaneous intestinal perforation nor necrotizing enterocolitis. Multivariate logistic regression analysis was performed to evaluate the association between the clinical group and death or neurodevelopmental impairment, controlling for multiple confounding factors including center. RESULT: Infants with surgical necrotizing enterocolitis had the highest rate of death before hospital discharge (53.5%) and death or neurodevelopmental impairment (82.3%) compared with infants in the spontaneous intestinal perforation group (39.1 and 79.3%) and no necrotizing enterocolitis/no spontaneous intestinal perforation group (22.1 and 53.3%; P<0.001). Similar results were observed for neurodevelopmental impairment among survivors. On logistic regression analysis, both spontaneous intestinal perforation and surgical necrotizing enterocolitis were associated with increased risk of death or neurodevelopmental impairment (adjusted odds ratio 2.21, 95% confidence interval (CI): 1.5, 3.2 and adjusted OR 2.11, 95% CI: 1.5, 2.9, respectively) and neurodevelopmental impairment among survivors (adjusted OR 2.17, 95% CI: 1.4, 3.2 and adjusted OR 1.70, 95% CI: 1.2, 2.4, respectively). CONCLUSION: Spontaneous intestinal perforation and surgical necrotizing enterocolitis are associated with a similar increase in the risk of death or neurodevelopmental impairment and neurodevelopmental impairment among extremely low birth weight survivors at 18-22 months corrected age.

Improved outcomes with a standardized feeding protocol for very low birth weight infants.

OBJECTIVE: The objective of this study was to evaluate the impact of a standardized enteral feeding protocol for very low birth weight (VLBW) infants on nutritional, clinical and growth outcomes. STUDY DESIGN: Retrospective analysis of VLBW cohorts 9 months before and after initiation of a standardized feeding protocol consisting of 6-8 days of trophic feedings, followed by an increase of 20 ml/kg/day. The primary outcome was days to reach full enteral feeds defined as 160 ml/kg/day. Secondary outcomes included rates of necrotizing enterocolitis and culture-proven sepsis, days of parenteral nutrition and growth end points. RESULT: Data were analyzed on 147 VLBW infants who received enteral feedings, 83 before ('Before') and 64 subsequent to ('After') feeding protocol initiation. Extremely low birth weight (ELBW) infants in the After group attained enteral volumes of 120 ml/kg/day (43.9 days Before vs 32.8 days After, P=0.02) and 160 ml/kg/day (48.5 days Before vs 35.8 days After, P=0.02) significantly faster and received significantly fewer days of parenteral nutrition (46.2 days Before vs 31.3 days After, P=0.01). Necrotizing enterocolitis decreased in the After group among VLBW (15/83, 18% Before vs 2/64, 3% After, P=0.005) and ELBW infants (11/31, 35% Before vs 2/26, 8% After, P=0.01). Late-onset sepsis decreased significantly in the After group (26/83, 31% Before vs 6/64, 9% After, P=0.001). Excluding those with weight <3rd percentile at birth, the proportion with weight <3rd percentile at discharge decreased significantly after protocol initiation (35% Before vs 17% After, P=0.03). CONCLUSION: These data suggest that implementation of a standardized feeding protocol for VLBW infants results in earlier successful enteral feeding without increased rates of major morbidities.

Inhaled nitric oxide in infants >1500 g and <34 weeks gestation with severe respiratory failure.

OBJECTIVE: Inhaled nitric oxide (iNO) use in infants >1500 g, but <34 weeks gestation with severe respiratory failure will reduce the incidence of death and/or bronchopulmonary dysplasia (BPD). STUDY DESIGN: Infants born at <34 weeks gestation with a birth weight >1500 g with respiratory failure were randomly assigned to receive placebo or iNO. RESULTS: Twenty-nine infants were randomized. There were no differences in baseline characteristics, but the status at randomization showed a statistically significant difference in the use of high-frequency ventilation (P=0.03). After adjustment for oxygenation index entry strata, there was no difference in death and/or BPD (adjusted relative risk (RR) 0.80, 95% confidence interval (CI) 0.43 to 1.48; P=0.50), death (adjusted RR 1.26, 95% CI 0.47 to 3.41; P=0.65) or BPD (adjusted RR 0.40, 95% CI 0.47 to 3.41; P=0.21). CONCLUSIONS: Although sample size limits our ability to make definitive conclusions, this small pilot trial of iNO use in premature infants >1500 g and <34 weeks with severe respiratory failure suggests that iNO does not affect the rate of BPD and/or death.

Diagnosis of patent ductus arteriosus by a neonatologist with a compact, portable ultrasound machine.

OBJECTIVES: To conduct a pilot study assessing a neonatologist's accuracy in diagnosing patent ductus arteriosus (PDA) using compact, portable ultrasound after limited training. STUDY DESIGN: Prospective study of premature infants scheduled for echocardiography for suspected PDA. A neonatologist with limited training performed study exams before scheduled exams. Sensitivity and specificity were calculated, compared to the scheduled echocardiogram interpreted by a cardiologist. RESULTS: There were 24 exams. Compared to the scheduled exam, the neonatologist's exam had sensitivity 69% (95% confidence interval (CI), 41 to 89%) and specificity 88% (95% CI, 47 to 99%). When a cardiologist interpreted the study exams, the sensitivity was 87% (95% CI, 60 to 98%) and specificity 71% (95% CI, 29 to 96%). CONCLUSION: A neonatologist with limited training was able to detect PDA with moderate success. A more rigorous training process or real-time transmission with cardiologist interpretation may substantially improve accuracy. Institutions with experienced technicians and on-site pediatric cardiologists may not gain from intensive training of neonatologists, but hospitals where diagnosis and treatment of PDA would be delayed may benefit from such processes.

Changes in mortality and morbidities among infants born at less than 25 weeks during the post-surfactant era.

OBJECTIVES: To compare mortality and death or major morbidity (DOMM) among infants <25 weeks estimated gestational age (EGA) born during two post-surfactant era time periods. STUDY DESIGN AND PATIENTS: Comparative cohort study of very low birthweight (501-1500 g) infants <25 weeks EGA in the NICHD Neonatal Research Network born during two post-surfactant era time periods (group I, 1991-1994, n=1408; group II, 1995-1998, n=1348). Perinatal and neonatal factors were compared, and group related mortality and DOMM risk were evaluated. RESULTS: Mortality was higher for group I (63.1% v 56.7%; p=0.0006). Antenatal steroids (ANS) and antenatal antibiotics (AABX), surfactant (p<0.0001), and bronchopulmonary dysplasia (p=0.0008) were more prevalent in group II. In a regression model that controlled for basic and delivery factors only, mortality risk was greater for group I than for group II (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.2 to 1.7); the addition of AABX and surfactant, or ANS (OR 0.97, 95% CI 0.79 to 1.2) to the model appeared to account for this difference. There was no difference in DOMM (86.8% v 88.4%; p=0.2), but risk was lower for group I in regression models that included ANS (OR 0.70, 95% CI 0.52 to 0.94). CONCLUSION: Survival to discharge was more likely during the more recent period because of group differences in ANS, AABX, and surfactant. However, this treatment shift may reflect an overall more aggressive management approach. More consistent application of treatment has led to improving survival of <25 week EGA infants during the post-surfactant era, but possibly at the cost of greater risk of major in-hospital morbidities.

The jaundiced newborn. Understanding and managing transitional hyperbilirubinemia.

Neonatal jaundice is one of the most common conditions diagnosed by the pediatrician. This normally benign transitional phenomenon is a dynamic balance between the production and elimination of bilirubin. These processes can be exacerbated by a number of pathophysiologic conditions, which cause either an increase in bilirubin production rates, such as hemolysis, or a decrease in bilirubin elimination rates, such as bilirubin conjugation defects. The most dangerous circumstance for an infant is the combination of increased bilirubin production with impaired elimination. These infants are at considerable risk for developing excessive and potentially dangerous hyperbilirubinemia and subsequent kernicterus. Therefore, the importance of early recognition of the imbalance is paramount. In this review, we will discuss the various risk factors associated with hyperbilirubinemia and describe strategies for the diagnosis and management of transitional hyperbilirubinemia.

Bedside functional imaging of the premature infant brain during passive motor activation.

BACKGROUND: Changes in regional brain blood flow and hemoglobin oxygen saturation occur in the human cortex in response to neural activation. Traditional functional radiologic methods cannot provide continuous, portable measurements. Imaging methods, which use near-infrared light allow for non-invasive measurements by taking advantage of the fact that hemoglobin is a strong absorber at these wavelengths. AIMS: To test the feasibility of a new optical functional imaging system in premature infants, and to obtain preliminary brain imaging of passive motor activation in this population. METHODS: A new optical imaging system, the Diffuse Optical Tomography System (DOTS), was used to provide real-time, bedside assessments. Custom-made soft flexible fiberoptic probes were placed on two extremely ill, mechanically ventilated 24 week premature infants, and three healthier 32 week premature infants. Passive motor stimulation protocols were used during imaging. RESULTS: Specific movement of the arm resulted in reproducible focal, contralateral changes in cerebral absorption. The data suggest an overall increase in blood volume to the imaged area, as well as an increase in deoxyhemoglobin concentration. These findings in premature infants differ from those expected in adults. CONCLUSIONS: In the intensive care setting, continuous non-invasive optical functional imaging could be critically important and, with further study, may provide a bedside monitoring tool for prospectively identifying patients at high risk for brain injury.

Serum bilirubin levels at 72 hours by selected characteristics in breastfed and formula-fed term infants delivered by cesarean section.

UNLABELLED: The present multicenter study analysed the relative impact of maternal and infant factors on serum bilirubin levels at 72 +/- 12 h in exclusively breastfed vs formula-fed term infants. End-tidal carbon monoxide levels corrected for ambient air (ETCOc), an index of bilirubin production, were measured in exclusively breastfed (B = 66) or formula-fed (F = 210) term infants at 2-8 h of age. Inclusion criteria included cesarean section to ensure a 3 d hospitalization, birthweight > or = 2,500 g, gestational age >37 wk and absence of any illness. The ETCOc for B infants and F infants did not differ significantly (1.3 +/- 0.7 ppm vs 1.3 +/- 0.8 ppm). The serum bilirubin level at 72 +/- 12 h was significantly higher in B infants than in F infants (8.5 +/- 3.4mg dl(-1) vs 6.7 +/- 3.4mg dl(-1) p < 0.001), as was the percentage weight loss from birthweight. Serum bilirubin levels were significantly higher in infants who were male, who did not have meconium-stained amniotic fluid, and in those whose mothers were insulin-dependent diabetics or hypertensive. There was no difference between groups in the need for phototherapy or exchange transfusion. CONCLUSION: Although higher bilirubin levels were observed in group B at 72 +/- 12 h compared with group F, this finding was not of clinical or therapeutic consequence in this study. The lack of difference in ETCOc between the groups may be a factor of the timing of ETCOc measurement in this study, or may suggest that early increased bilirubin production is not a significant contributor to jaundice observed in exclusively breastfed infants. Key words: bilirubin, breastfeeding, jaundice

Secondary infection presenting as recurrent pulmonary hypertension.

Primary infection in the neonate, especially group B streptococcal infection, has long been recognized as a cause of persistent pulmonary hypertension of the newborn (PPHN), sometimes requiring treatment with inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO). However, secondary nosocomial infections in the neonatal period have not been widely reported as a cause of severe recurrent pulmonary hypertension (PHTN). We now present two cases of secondary infection in the neonate leading to significant PHTN. In both cases, the infants presented with PPHN soon after birth, requiring transfer to a level 3 neonatal intensive care unit and treatment with high-frequency oscillatory ventilation and iNO. After successful resolution of the initial PPHN, including extubation to nasal cannula, both infants developed signs of severe recurrent PHTN, leading to reintubation, high-frequency oscillatory ventilation and iNO therapy, and consideration of ECMO. In both cases, blood cultures taken at the time of recurrence of PHTN returned positive, one for Staphylococcus epidermidis, the other for methicillin-resistant Staphylococcus aureus. These unusual cases present the possibility of severe recurrent PHTN requiring iNO or ECMO in the setting of secondary infection. We speculate that these infants, although extubated after their first episodes of PHTN, were at risk for recurrence of PHTN due to continued pulmonary vascular reactivity.

Noninvasive functional imaging of human brain using light.

Analysis of photon transit time for low-power light passing into the head, and through both skull and brain, of human subjects allowed for tomographic imaging of cerebral hemoglobin oxygenation based on photon diffusion theory. In healthy adults, imaging of changes in hemoglobin saturation during hand movement revealed focal, contralateral increases in motor cortex oxygenation with spatial agreement to activation maps determined by functional magnetic resonance imaging; in ill neonates, imaging of hemoglobin saturation revealed focal regions of low oxygenation after acute stroke, with spatial overlap to injury location determined by computed tomography scan. Because such slow optical changes occur over seconds and co-localize with magnetic resonance imaging vascular signals whereas fast activation-related optical changes occur over milliseconds and co-localize with EEG electrical signals, optical methods offer a single modality for exploring the spatio-temporal relationship between electrical and vascular responses in the brain in vivo, as well as for mapping cortical activation and oxygenation at the bedside in real-time for clinical monitoring.

Decreased use of neonatal extracorporeal membrane oxygenation (ECMO): how new treatment modalities have affected ECMO utilization.

OBJECTIVE: Over the last decade, several new therapies, including high-frequency oscillatory ventilation (HFOV), exogenous surfactant therapy, and inhaled nitric oxide (iNO), have become available for the treatment of neonatal hypoxemic respiratory failure. The purpose of this retrospective study was to ascertain to what extent these modalities have impacted the use of neonatal extracorporeal membrane oxygenation (ECMO) at our institution. METHODS: Patients from 2 time periods were evaluated: May 1, 1993 to November 1, 1994 (group 1) and May 1, 1996 to November 1, 1997 (group 2). During the first time period (group 1), HFOV was not consistently used; beractant (Survanta) use for meconium aspiration syndrome (MAS), persistent pulmonary hypertension of the newborn (PPHN), and pneumonia was under investigation; and iNO was not yet available. During the second time period (group 2), HFOV and beractant treatment were considered to be standard therapies, and iNO was available to patients with oxygenation index (OI) >/=25 x 2 at least 30 minutes apart, or on compassionate use basis. Patients were included in the data collection if they met the following entry criteria: 1) OI >15 x 1 within the first 72 hours of admission; 2) EGA >/=35 weeks; 3) diagnosis of MAS, PPHN or sepsis/pneumonia; 4) <5 days of age on admission; and 5) no congenital heart disease, diaphragmatic hernia, or lethal congenital anomaly. RESULTS: Of the 49 patient in group 1, 21 (42.8%) required ECMO therapy. Of these ECMO patients, 14 (66.6%) had received diagnoses of MAS or PPHN. Only 3 of the patients that went on to ECMO received beractant before the initiation of bypass (14.3%). All ECMO patients in group 1 would have met criteria for iNO had it been available. Of all patients in group 1, 18 (36.7%) were treated with HFOV, and 13 (26.5%) received beractant. Of the 47 patients in group 2, only 13 (27.7%) required ECMO therapy (compared with group 1). Of these ECMO patients, only 5 (38.5%) had diagnoses of MAS or PPHN, with the majority of patients (61.5%) requiring ECMO for sepsis/pneumonia, with significant cardiovascular compromise. Only 5 of these ECMO patients, all outborn, did not receive iNO before cannulation because of the severity of their clinical status on admission. Of all patients in group 2, 41 (87.2%) were treated with HFOV (compared with group 1), 42 (89.3%) received beractant (compared with group 1), and 18 (44.7%) received iNO. CONCLUSIONS: The results indicate that ECMO was used less frequently when HFOV, beractant and iNO was more commonly used. The differences in treatment modalities used and subsequent use of ECMO were statistically significant. We speculate that, in this patient population, the diagnostic composition of neonatal ECMO patients has changed over time.