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Neonatal Research Network

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Formed in 1986, the NICHD Neonatal Research Network (NRN) is a collaborative network of neonatal intensive care units across the United States. The NRN comprises 18 clinical centers and a data coordinating center. Focused on newborns, particularly extremely low birth weight (ELBW) infants, the NRN aims "to facilitate the advancement of neonatal care by establishing a network of academic centers that, by rigorous patient evaluation using common protocols, can study the required numbers of patients and can provide answers more rapidly than individual centers acting alone (RFA HD10-003)." To fulfill this mission, the NRN has completed or is implementing 18 observational studies and 34 interventional trials (details of which are available at and on the NRN website at External Web Site Policy).

Topic Areas

Preterm birth complications. According to Hostetter (Hostetter, M. K. 2012). What we don't see. New England Journal of Medicine, 366, 1328–1334. PMID: 22475596), in 2008, 12% of neonatal deaths worldwide were caused by complications from preterm birth. NRN studies in this area include:
  • Overall preterm birth complications and outcomes
    • Generic Database (GDB) of Very Low Birth Weight Infants. The GDB is a registry of very low birth weight infants born alive in NRN centers. Centers collect data on mothers and their infants, the therapies they received, and the infants' outcomes at discharge. These data are analyzed to find associations and trends in baseline data, treatments, and infant outcomes and to develop future NRN trials. The NRN has registered more than 70,000 infants in this database since its inception. These data also form the basis of the NRN's Extremely Preterm Birth Outcome Data tool, which gives physicians and parents predictive estimates of infant mortality and morbidity using five key factors: gestational age, birth weight, sex, singleton/multiple birth, and whether the mother received corticosteroids before delivery.

    • Moderate Preterm Registry. In March 2012, the NRN began collecting similar baseline data on infants born between 29 and 33 weeks' gestational age to estimate the frequency of maternal and perinatal events, morbidities, and hospital outcomes of moderately preterm infants.

    • Follow-Up Study of High- Risk Infants. Begun in 1998, the NRN's Follow-Up Study is a cohort of surviving ELBW infants who have neurodevelopmental, neurosensory, and functional assessments at a corrected age of 24 months to identify maternal and neonatal risk and protective factors for neurodevelopmental outcome. To date, the NRN has followed more than 12,000 children.

  • Bronchopulmonary dysplasia (BPD), also called chronic lung disease, is a serious respiratory condition that affects premature infants. These babies generally have inflammation or scarring of the lungs and must be on some form of oxygen therapy via nasal prongs, a mask, or a breathing tube.
    • Surfactant Positive Airway Pressure and Pulse Oximetry Trial (SUPPORT). This trial, co-funded by the National Heart, Lung, and Blood Institute, found that higher oxygen levels improved preterm infants' survival but increased the risk of retinopathy of prematurity (SUPPORT Study Group of the Eunice Kennedy Shriver NICHD Neonatal Research Network [2010] . Target ranges of oxygen saturation in extremely preterm infants. New England Journal of Medicine, 372, 1959–19 69. PMID: 20472937). It also found that continuous positive airway pressure (CPAP) was as effective as the traditional ventilator/surfactant therapy in treating BPD in these infants, but CPAP may result in fewer complications (SUPPORT Study Group of the Eunice Kennedy Shriver NICHD Neonatal Research Network [2010]. Early CPAP versus surfactant in extremely preterm infants. New England Journal of Medicine, 362, 1970–1979. PMID: 20472939). Follow-up results at a corrected age of 18 to 22 months showed no significant difference in death or neurodevelopmental impairment between infants who received CPAP and those who received surfactant/intubation, and no difference between those who received lower and higher oxygen levels (Vaucher, Y. E., et a; [2012]. Neurodevelopmental outcomes in the early CPAP and pulse oximetry trial. New England Journal of Medicine, 367, 2495− 2504. PMID: 23268664). Infants recruited into a neuroimaging secondary study examining early head ultrasound and magnetic resonance imaging (MRI) findings compared with neurodevelopmental outcomes at 18 to 22 months are currently being followed up at 6− 7 years of age to see how well the initial MRIs predict outcomes at school age.

    • Hydrocortisone for BPD (NCT01353313). This study is testing the safety and efficacy of a 10-day course of hydrocortisone for infants with a gestational age of less than 30 weeks who are intubated with breathing tubes at 14 to 28 days of life. Infants are randomized to receive either hydrocortisone or a saline placebo. This study will determine whether hydrocortisone improves infants' survival without moderate or severe BPD and without moderate or severe neurodevelopmental impairment at a corrected age of 24 months.

    • Do Antenatal Steroids Affect Maturation of the Amplitude Integrated Electroencephalogram (aEEG) in Late Preterm Infants? The NICHD Maternal-Fetal Medicine Units (MFMU) Network's Antenatal Late Preterm Steroids (ALPS) study is a randomized trial to determine whether corticosteroids given to mothers before birth decrease the need for respiratory support among their late- preterm infants. The NRN is working with the MFMU Network to enroll infants from the ALPS trial into a secondary study to see whether infants whose mothers received antenatal corticosteroids show aEEG patterns consistent with increased maturity (e.g., more periods of quiet sleep) compared to those whose mothers received a placebo.

  • Necrotizing enterocolitis (NEC) is a condition in which the intestines lack oxygen or blood flow. NEC occurs in 5% to 15% of ELBW infants, and isolated intestinal perforation (IP), in which a hole develops in the intestines, leaking fluid into the abdominal cavity, affects an estimated 4% of these infants. Outcome for infants with NEC or IP is poor: 49% die, and half of the surviving infants are impaired.
    • Necrotizing Enterocolitis Surgery Trial (NEST) (NCT01029353). This trial is testing the hypothesis that treatment with an initial laparotomy (an extensive surgery that removes the damaged intestines), rather than a less-invasive initial drainage, will increase survival without neurodevelopmental impairment at an adjusted age of 18 to 22 months . Infants are randomized to receive one of the initial surgeries; infants not recruited into the randomized trial may be included in a parallel observational cohort.

  • Anemia. Virtually all ELBW infants become anemic in early life, and approximately 90% receive one or more blood transfusions for a variety of reasons.
    • Transfusion of Prematures (TOP) trial (NCT01702805). Different physicians decide to start transfusions at different hemoglobin thresholds. This NRN trial randomizes infants with a birth weight under 1,000 grams and a gestational age of less than 29 weeks to receive red blood cell transfusions at either a higher (liberal transfusion) or lower (restrictive transfusion) hemoglobin threshold to see whether maintaining a higher hemoglobin level will improve survival and neurodevelopmental outcomes at 24 months of age.
  • Birth asphyxia. Worldwide, 9% of neonatal deaths in 2008 were caused by birth asphyxia (Hostetter 2012). Hypoxic-ischemic encephalopathy (HIE) is a rare but life-threatening condition characterized by brain injury due to a lack of oxygen at or shortly after birth. An estimated 50% to 75% of infants with severe HIE die, and 55% of these deaths occur in the first month. Up to 80% of survivors develop significant long-term disabilities, such as intellectual impairment, epilepsy, and cerebral palsy. NRN studies in this area include:
    • Late Hypothermia for Hypoxic-Ischemic Encephalopathy (NCT00614744). Some infants with birth asphyxia do not reach hospitals or do not exhibit symptoms of HIE until after 6 hours of age. This randomized trial is testing whether whole-body hypothermia initiated between 6 and 24 hours of age and continued for 96 hours will benefit infants with HIE as measured by reduced death or disability at 18 to 22 months of age.

    • Optimizing Cooling Strategies at <6 Hours of Age for Neonatal Hypoxic-Ischemic Encephalopathy (NCT01192776). The Optimizing Cooling trial is examining ways to fine-tune the whole-body hypothermia treatment. Infants are randomized to receive hypothermia for either 72 hours or 120 hours and cooled to either 33.5°C or 32.0°C to see which options may improve the chance of survival and produce better neurodevelopmental outcomes at a corrected age of 18 to 22 months.

  • Sepsis. In 2008, 6% of neonatal deaths worldwide were caused by sepsis (Hostetter 2012). NRN studies in this area include:
    • Clinical Presentation of Neonatal Sepsis among Neonates Born to Mothers with Chorioamnionitis. This study, co-funded by the Centers for Disease Control and Prevention, is a retrospective review of infants in the NRN Early Onset Sepsis study, which found that the pathogens most frequently associated with early- onset sepsis were group B streptococci and Escherichia coli. This review will look at how many of the babies born to mothers with chorioamnionitis were asymptomatic at birth but later developed signs or symptoms of early-onset neonatal group B streptococcal (GBS) disease or non-GBS disease.

  • Congenital anomalies. In 2008, 3% of neonatal deaths worldwide were caused by congenital anomalies (Hostetter 2012). NRN studies include:
    • Anonymized Database for Studies of Genomic Impact on Morbidity and Mortality Among High-Risk Infants. Serum samples and baseline data were collected from 934 early- preterm infants. These samples are currently undergoing DNA analysis; resulting data will be analyzed looking for genetic associations with a variety of neonatal conditions.

    • Infants with Trisomy 18 and Trisomy 13. As part of its Generic Database (GDB), the NRN collects data on very low birth weight infants born with trisomy 13 and trisomy 18, rare genetic conditions in which infants have additional copies of chromosome 13 or 18. Trisomy 13 and 18 result in life-threatening conditions—Patau syndrome and Edwards syndrome, respectively. Analysis for the NRN data from 1994-2009 (Boghossian NS; et al [2014]. Mortality and Morbidity of VLBW Infants with Trisomy 13 or Trisomy 18. Pediatrics. 2014 Jan 20. PMID24446439) found that of the 52,262 infants in GDB, 38 (0.07%) had T13 and 128 (0.24%) had T18. In addition, the intensity of care given to these infants in the delivery room varied depending on whether the anolmaly was diagnosed before or after birth. Diagnosis also affected the plans for care, or withdrawal of care, once out of the delivery room.

  • Reducing neonatal morbidities. In addition to reducing neonatal mortality, the NRN is interested in methods to reduce or ameliorate neonatal morbidities:
    • Neurodevelopmental Effects of Donor Human Milk vs. Preterm Formula in ELBW infants (The MILK trial, NCT01534481). Strong preliminary evidence suggests that maternal breast milk confers multiple health benefits to ELBW infants, including up to an additional 8 points in IQ over non-breastfed counterparts. In addition, rates of sepsis and NEC are lower in these infants, and they experience shorter hospital stays and fewer rehospitalizations in the first year of life. The MILK trial is testing whether fortified donor human milk versus preterm formula will improve neurodevelopmental and other health outcomes for ELBW infants receiving no or minimal maternal milk at a corrected age of 24 months.

    • Inositol for reducing retinopathy of prematurity. Retinopathy of prematurity (ROP) is an abnormal growth of the blood vessels in the eye that occurs primarily in very premature infants when these blood vessels, sensitive to extreme oxygen levels, must finish developing outside the protective environment of the uterus. ROP is a leading cause of blindness and other vision impairments. Co-funded by the National Eye Institute, the inositol trials are testing whether 6-myoinositol can reduce severe ROP. Inositol is a naturally occurring sugar alcohol produced by the fetus and placenta and is present in high levels in fetal blood throughout pregnancy. Normal blood inositol levels fall rapidly after birth. The NRN has completed three pilot studies testing the safety and efficacy of administering inositol in concentrations similar to those occurring naturally in utero. The NRN is currently implementing a large, randomized, Phase III trial of inositol (NCT01954082). This main trial is currently under development, with recruitment expected to start in f all 2013.

High-Impact Results

Over its 27-year history, the Neonatal Research Network has published more than 275 peer-reviewed papers. Presented below are some high-impact results from NRN studies. A complete listing of NRN studies and papers is available on the NRN website External Web Site Policy.

  • Hypothermia as a safe and effective therapy for birth asphyxia. The NRN conducted pioneering research on hypothermia as a treatment for birth asphyxia and HIE. The whole-body hypothermia randomized, controlled trial involved 208 infants less than 6 hours old who had evidence of moderate to severe brain injury caused by restricted blood flow. In seeking to learn whether hypothermia treatment can reduce death or disability, the investigators used cooling blankets with careful esophageal temperature monitoring to decrease some of the infants' body temperatures to 33.5°C (92.3°F) for 72 hours, followed by slow re-warming. The trial found that whole-body hypothermia is both a safe and effective therapy—infants with moderate or severe HIE who received hypothermia were more likely to survive to a corrected age of 18-22 months with less neurodevelopmental impairment (Shankaran, S., et al. [ 2005]. Whole-body hypothermia for neonates with hypoxic-ischemic encephalopathy. New England Journal of Medicine, 353, 1574–1584. PMID: 16221780). Surviving children were recently re-examined at school age; the study found that those who received hypothermia were more likely to survive to 6 or 7 years of age and were no more likely than the routine care group to experience a physical or cognitive impairment (Shankaran, S., et al. [2012]. Childhood outcomes after hypothermia for neonatal encephalopathy. New England Journal of Medicine, 366, 2085–2092. PMID: 22646631).

  • Earlier jaundice treatment with phototherapy reduces brain injury in extremely premature infants. Jaundice results when newborn infants have high levels of bilirubin in their blood — high levels of bilirubin can cause brain injury or kernicterus. Bilirubin can, however, also function as an antioxidant, and so modest amounts may have some benefit. Phototherapy is commonly used in infants and has been shown to reduce levels of bilirubin. The NRN's Phototherapy Trial tested whether phototherapy initiated at a lower bilirubin threshold (aggressive phototherapy) versus a higher threshold (conservative phototherapy) would affect neurodevelopmental impairment or death in infants weighing less than 1000 grams at birth. Aggressive phototherapy reduced the rate of neurodevelopmental impairment at a corrected age of 18 to 22 months from 30% to 26%, and the rate of rate of profound neurodevelopmental impairment from 13% to 9%. However, the reduction in impairment may be offset by an increase in death in the smaller infants weighing 501to 750 grams at birth. (Morris, B. H., et al. [2008]. Aggressive vs. conservative phototherapy for infants with extremely low birth weight. New England Journal of Medicine, 359, 1885− 1896. PMID: 18971491).

  • Vitamin A. Evidence suggests that supplementation with vitamin A may help to reduce the risk of chronic lung disease and sepsis among ELBW infants. The NRN conducted a multicenter, randomized trial to assess the effectiveness and safety of 5000 IU of vitamin A administered intramuscularly three times per week for 4 weeks to 807 infants in need of respiratory support 24 hours after birth, compared to a sham treatment. The trial showed that this regimen reduced biochemical evidence of vitamin A deficiency and slightly decreased the risk of chronic lung disease in ELBW infants. (Tyson, J. E., et al. [1999]. Vitamin A supplementation for extremely-low-birth-weight infants. New England Journal of Medicine, 340, 1962− 1968. PMID: 10379020).

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