There is a paucity of information on the maintenance of body temperature at birth for low birth weight infants.
We examined the distribution of temperatures in low birth weight infants on admission ...to the NICUs in the Neonatal Research Network centers and determined whether admission temperature was associated with antepartum and birth variables and selected morbidities and mortality.
Infants without major congenital anomalies born during 2002 and 2003 with birth weights of 401 to 1499 g who were admitted directly from the delivery room to the NICU were included. Bivariate associations between antepartum/birth variables and admission temperature and selected morbidities/mortality and admission temperature were examined, followed by multivariable linear or logistic regressions to detect independent associations.
There were 5277 study infants and the mean (+/-SD) birth weight and gestational age were 1036 +/- 286 g and 28 +/- 3 weeks, respectively. The distribution of admission temperatures was 14.3% at < 35 degrees C, 32.6% between 35 and 35.9 degrees C, 42.3% between 36 and 36.9 degrees C, and 10.8% at > or = 37 degrees C. The estimate of birth weight on admission temperature with and without intubation was +0.13 degrees C and +0.04 degrees C per 100-g increase in birth weight, respectively. The mean admission temperature for each center varied from 1.5 degrees C below to 0.3 degrees C above a reference center. On adjusted analyses, admission temperature was inversely related to mortality (28% increase per 1 degrees C decrease) and late-onset sepsis (11% increase per 1 degrees C decrease) but not to intraventricular hemorrhage, necrotizing enterocolitis, or duration of conventional ventilation.
Preventing decreases in temperature at birth among low birth weight infants remains a challenge. Associations with intubation and center of birth suggest that assessment of temperature control for infants intubated in the delivery room may be beneficial. Whether the admission temperature is part of the casual path or a marker of mortality needs additional study.
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.
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.
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.
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.
To determine the effect of 3 distinct comparison groups on associations between placental abnormalities and neonatal hypoxic-ischemic encephalopathy (HIE).
This single-center, prospective ...case-control study of singletons of gestational age ≥36 weeks with predefined criteria for HIE (n = 30) and 3 control groups was conducted from June 2015 to January 2018. The control groups were infants born by repeat cesarean delivery (n = 60), infants born small for gestational age (SGA; n = 80), and infants receiving positive-pressure ventilation (PPV) at birth (n = 70). One pathologist blinded to infant category reviewed placental sections using the Amsterdam Placental Workshop criteria. Logistic regression with group contrasts relative to HIE was used to analyze primary placental pathologies, and ORs with 95% CIs provided effect sizes.
The odds of maternal vascular malperfusion were increased among HIE group placentas compared with placentas of the repeat cesarean delivery (OR, 4.50; 95% CI, 1.45-14.00) and PPV (3.88; 1.35-11.16) groups, but not those of the SGA group. The odds of fetal vascular malperfusion were increased in the HIE group compared with the SGA group (OR, 9.75; 95% CI, 1.85-51.51). The odds of acute chorioamnionitis were higher in the HIE group compared only with the repeat cesarean delivery group, reflecting a similar incidence of chorioamnionitis in SGA group and PPV group placentas. The absence of placental findings was lowest in the HIE group (6.7%), followed by the SGA (18.8%), PPV (31.4%), and repeat cesarean delivery (75%) groups.
Associations with placental abnormalities among infants with HIE varied based on the specific placental abnormality and the control group. Potentially important associations between placental pathology and HIE may be obscured if control groups are not well designed.
Extremely preterm infants contribute disproportionately to neonatal morbidity and mortality.
To review 20-year trends in maternal/neonatal care, complications, and mortality among extremely preterm ...infants born at Neonatal Research Network centers.
Prospective registry of 34,636 infants, 22 to 28 weeks' gestation, birth weight of 401 to 1500 g, and born at 26 network centers between 1993 and 2012.
Extremely preterm birth.
Maternal/neonatal care, morbidities, and survival. Major morbidities, reported for infants who survived more than 12 hours, were severe necrotizing enterocolitis, infection, bronchopulmonary dysplasia, severe intracranial hemorrhage, cystic periventricular leukomalacia, and/or severe retinopathy of prematurity. Regression models assessed yearly changes and were adjusted for study center, race/ethnicity, gestational age, birth weight for gestational age, and sex.
Use of antenatal corticosteroids increased from 1993 to 2012 (24% 348 of 1431 infants) to 87% (1674 of 1919 infants; P < .001), as did cesarean delivery (44% 625 of 1431 births to 64% 1227 of 1921; P < .001). Delivery room intubation decreased from 80% (1144 of 1433 infants) in 1993 to 65% (1253 of 1922) in 2012 (P < .001). After increasing in the 1990s, postnatal steroid use declined to 8% (141 of 1757 infants) in 2004 (P < .001), with no significant change thereafter. Although most infants were ventilated, continuous positive airway pressure without ventilation increased from 7% (120 of 1666 infants) in 2002 to 11% (190 of 1756 infants) in 2012 (P < .001). Despite no improvement from 1993 to 2004, rates of late-onset sepsis declined between 2005 and 2012 for infants of each gestational age (median, 26 weeks 37% {109 of 296} to 27% {85 of 320}; adjusted relative risk RR, 0.93 95% CI, 0.92-0.94). Rates of other morbidities declined, but bronchopulmonary dysplasia increased between 2009 and 2012 for infants at 26 to 27 weeks' gestation (26 weeks, 50% 130 of 258 to 55% 164 of 297; P < .001). Survival increased between 2009 and 2012 for infants at 23 weeks' gestation (27% 41 of 152 to 33% 50 of 150; adjusted RR, 1.09 95% CI, 1.05-1.14) and 24 weeks (63% 156 of 248 to 65% 174 of 269; adjusted RR, 1.05 95% CI, 1.03-1.07), with smaller relative increases for infants at 25 and 27 weeks' gestation, and no change for infants at 22, 26, and 28 weeks' gestation. Survival without major morbidity increased approximately 2% per year for infants at 25 to 28 weeks' gestation, with no change for infants at 22 to 24 weeks' gestation.
Among extremely preterm infants born at US academic centers over the last 20 years, changes in maternal and infant care practices and modest reductions in several morbidities were observed, although bronchopulmonary dysplasia increased. Survival increased most markedly for infants born at 23 and 24 weeks' gestation and survival without major morbidity increased for infants aged 25 to 28 weeks. These findings may be valuable in counseling families and developing novel interventions.
clinicaltrials.gov Identifier: NCT00063063.
Benefits of identifying risk factors for bronchopulmonary dysplasia in extremely premature infants include providing prognostic information, identifying infants likely to benefit from preventive ...strategies, and stratifying infants for clinical trial enrollment.
To identify risk factors for bronchopulmonary dysplasia, and the competing outcome of death, by postnatal day; to identify which risk factors improve prediction; and to develop a Web-based estimator using readily available clinical information to predict risk of bronchopulmonary dysplasia or death.
We assessed infants of 23-30 weeks' gestation born in 17 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network and enrolled in the Neonatal Research Network Benchmarking Trial from 2000-2004.
Bronchopulmonary dysplasia was defined as a categorical variable (none, mild, moderate, or severe). We developed and validated models for bronchopulmonary dysplasia risk at six postnatal ages using gestational age, birth weight, race and ethnicity, sex, respiratory support, and Fi(O(2)), and examined the models using a C statistic (area under the curve). A total of 3,636 infants were eligible for this study. Prediction improved with advancing postnatal age, increasing from a C statistic of 0.793 on Day 1 to a maximum of 0.854 on Day 28. On Postnatal Days 1 and 3, gestational age best improved outcome prediction; on Postnatal Days 7, 14, 21, and 28, type of respiratory support did so. A Web-based model providing predicted estimates for bronchopulmonary dysplasia by postnatal day is available at https://neonatal.rti.org.
The probability of bronchopulmonary dysplasia in extremely premature infants can be determined accurately using a limited amount of readily available clinical information.
Objective To examine the predictive ability of stage of hypoxic-ischemic encephalopathy (HIE) for death or moderate/severe disability at 18 months among neonates undergoing hypothermia. Study design ...Stage of encephalopathy was evaluated at <6 hours of age, during study intervention, and at discharge among 204 participants in the National Institute of Child Health and Human Development Neonatal Research Network Trial of whole body hypothermia for HIE. HIE was examined as a predictor of outcome by regression models. Results Moderate and severe HIE occurred at <6 hours of age among 68% and 32% of 101 hypothermia group infants and 60% and 40% of 103 control group infants, respectively. At 24 and 48 hours of study intervention, infants in the hypothermia group had less severe HIE than infants in the control group. Persistence of severe HIE at 72 hours increased the risk of death or disability after controlling for treatment group. The discharge exam improved the predictive value of stage of HIE at <6 hours for death/disability. Conclusions On serial neurologic examinations, improvement in stage of HIE was associated with cooling. Persistence of severe HIE at 72 hours and an abnormal neurologic exam at discharge were associated with a greater risk of death or disability.
Early-onset sepsis (EOS) remains a potentially fatal newborn condition. Ongoing surveillance is critical to optimize prevention and treatment strategies.
To describe the current incidence, ...microbiology, morbidity, and mortality of EOS among a cohort of term and preterm infants.
This prospective surveillance study included a cohort of infants born at a gestational age (GA) of at least 22 weeks and birth weight of greater than 400 g from 18 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network from April 1, 2015, to March 31, 2017. Data were analyzed from June 14, 2019, to January 28, 2020.
Early-onset sepsis defined by isolation of pathogenic species from blood or cerebrospinal fluid culture within 72 hours of birth and antibiotic treatment for at least 5 days or until death.
A total of 235 EOS cases (127 male 54.0%) were identified among 217 480 newborns (1.08 95% CI, 0.95-1.23 cases per 1000 live births). Incidence varied significantly by GA and was highest among infants with a GA of 22 to 28 weeks (18.47 95% CI, 14.57-23.38 cases per 1000). No significant differences in EOS incidence were observed by sex, race, or ethnicity. The most frequent pathogens were Escherichia coli (86 36.6%) and group B streptococcus (GBS; 71 30.2%). E coli disease primarily occurred among preterm infants (68 of 131 51.9%); GBS disease primarily occurred among term infants (54 of 104 51.9%), with 24 of 45 GBS cases (53.3%) seen in infants born to mothers with negative GBS screening test results. Intrapartum antibiotics were administered to 162 mothers (68.9%; 110 of 131 84.0% preterm and 52 of 104 50.0% term), most commonly for suspected chorioamnionitis. Neonatal empirical antibiotic treatment most frequently included ampicillin and gentamicin. All GBS isolates were tested, but only 18 of 81 (22.2%) E coli isolates tested were susceptible to ampicillin; 6 of 77 E coli isolates (7.8%) were resistant to both ampicillin and gentamicin. Nearly all newborns with EOS (220 of 235 93.6%) displayed signs of illness within 72 hours of birth. Death occurred in 38 of 131 infected infants with GA of less than 37 weeks (29.0%); no term infants died. Compared with earlier surveillance (2006-2009), the rate of E coli infection increased among very low-birth-weight (401-1500 g) infants (8.68 95% CI, 6.50-11.60 vs 5.07 95% CI, 3.93-6.53 per 1000 live births; P = .008).
In this study, EOS incidence and associated mortality disproportionately occurred in preterm infants. Contemporary cases have demonstrated the limitations of current GBS prevention strategies. The increase in E coli infections among very low-birth-weight infants warrants continued study. Ampicillin and gentamicin remained effective antibiotics in most cases, but ongoing surveillance should monitor antibiotic susceptibilities of EOS pathogens.
Objective To determine whether small for gestational age (SGA) infants born at <27 weeks gestational age (GA) are at increased risk for mortality, morbidity, and growth and neurodevelopmental ...impairment at 18-22 months corrected age. Study design This was a retrospective cohort study from National Institute of Child Health and Human Development Neonatal Research Network's Generic Database and Follow-Up Studies. Infants born at <27 weeks GA between January 2006 and July 2008 were included. SGA was defined as birth weight <10th percentile for GA based on Olsen growth curves. Infants with birth weight ≥10th percentile for GA were classified as non-SGA. Maternal and infant characteristics, neonatal outcomes, and neurodevelopmental data were compared in SGA and non-SGA infants. Neurodevelopmental impairment was defined as any of the following: cognitive score <70 on the Bayley Scales of Infant Development III, moderate or severe cerebral palsy, bilateral hearing loss (with and without amplification), or blindness (bilateral vision <20/200). Logistic regression analysis was applied to evaluate the associations between SGA status and death or neurodevelopmental impairment. Results The SGA group comprised 385 infants; the non-SGA group, 2586 infants. Compared with mothers of non-SGA infants, mothers of SGA infants were more likely to have a high school education, prenatal care, cesarean delivery, pregnancy-induced hypertension, and antenatal corticosteroid exposure. Compared with non-SGA infants, SGA infants had higher mortality and were more likely to have postnatal growth failure, prolonged mechanical ventilation, and postnatal steroid use. SGA status was associated with increased risk of death or neurodevelopmental impairment (OR, 3.91; 95% CI, 2.91-5.25; P < .001). Conclusion SGA status in infants born at <27 weeks GA is associated with an increased likelihood of postnatal steroid use, mortality, growth failure, and neurodevelopmental impairment at 18-22 months corrected age.
Objective To evaluate the association between early hypocarbia and 18- to 22-month outcome among neonates with hypoxic-ischemic encephalopathy. Study design Data from the National Institute of Child ...Health and Human Development Neonatal Research Network randomized, controlled trial of whole-body hypothermia for neonatal hypoxic-ischemic encephalopathy were used for this secondary observational study. Infants (n = 204) had multiple blood gases recorded from birth to 12 hours of study intervention (hypothermia versus intensive care alone). The relationship between hypocarbia and outcome (death/disability at 18 to 22 months) was evaluated by unadjusted and adjusted analyses examining minimum PCO2 and cumulative exposure to PCO2 <35 mm Hg. The relationship between cumulative PCO2 <35 mm Hg (calculated as the difference between 35 mm Hg and the sampled PCO2 multiplied by the duration of time spent <35 mm Hg) and outcome was evaluated by level of exposure (none-high) using a multiple logistic regression analysis with adjustments for pH, level of encephalopathy, treatment group (±hypothermia), and time to spontaneous respiration and ventilator days; results were expressed as odds ratios and 95% confidence intervals. Alternative models of CO2 concentration were explored to account for fluctuations in CO2. Results Both minimum PCO2 and cumulative PCO2 <35 mm Hg were associated with poor outcome ( P < .05). Moreover, death/disability increased with greater cumulative exposure to PCO2 <35 mm Hg. Conclusions Hypocarbia is associated with poor outcome after hypoxic-ischemic encephalopathy.