Outcome of Term Infants Using Apgar Scores at 10 Minutes Following Hypoxic-Ischemic Encephalopathy
OBJECTIVE: The objective of this study was to determine whether Apgar scores at 10 minutes are associated with death or disability in early childhood after perinatal hypoxic-ischemic encephalopathy.
METHODS: This was a secondary analysis of infants who were enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network hypothermia trial. Infants who were born at ≥36 weeks’ gestation and had clinical and/or biochemical abnormalities at birth and encephalopathy at <6 hours were studied. Logistic regression and classification and regression-tree analysis were used to determine associations between Apgar scores at 10 minutes and neurodevelopmental outcome, adjusting for covariates. Death or disability (moderate or severe) at 18 to 22 months of age was the measured outcome.
RESULTS: Twenty of 208 infants were excluded (missing data). More than 90% of the infants had Apgar scores of 0 to 2 at 1 minute, and Apgar scores at 5 and 10 minutes shifted to progressively higher values; at 10 minutes, 27% of infants had Apgar scores of 0 to 2. After adjustment, each point decrease in Apgar score at 10 minutes was associated with a 45% increase in the odds of death or disability. Death or disability occurred in 76%, 82%, and 80% of infants with 10-minute Apgar scores of 0, 1, and 2, respectively. Classification and regression-tree analysis indicated that Apgar scores at 10 minutes were discriminators of outcome.
CONCLUSIONS: Apgar scores at 10 minutes provide useful prognostic data before other evaluations are available for infants with hypoxic-ischemic encephalopathy. Death or moderate/severe disability is common but not uniform with Apgar scores of <3; caution is needed before adopting a specific time interval to guide duration of resuscitation.
Apgar scores are almost universally assigned to newborns at birth in the United States and most developed countries. The original intent of the Apgar score was to provide a description of the newborn's physical condition and enable comparison of obstetric practice, maternal analgesia, and resuscitative efforts.1 The Apgar score uses readily available observations, deemed to be objective and acquired without interfering in delivery room care. Apgar et al2 demonstrated an inverse relationship between neonatal mortality and the 1-minute Apgar in 15348 infants. These observations were subsequently extended to the 5-minute Apgar score in >17000 infants who were born at 13 institutions.3 Although the interobserver reliability of assigning Apgar scores and equal weighting of the components of the Apgar score remain a concern,4,5 the predictive relationship between the 5-minute Apgar score and neonatal mortality was confirmed almost 50 years after introduction of the Apgar score among a cohort of 145627 singleton preterm and term newborns in a retrospective cohort from a single institution.6
The Neonatal Resuscitation Program (NRP) recommends assignment of Apgar scores beyond 5 minutes of age when the Apgar score is <7 (the extended Apgar score) to indicate the response to interventions/resuscitation at birth.7 The relationship between the extended Apgar score and outcome at 7 years of age (mortality and cerebral palsy [CP]) has been analyzed from ∼49000 singleton live births during 1959–1966 as part of the National Collaborative Perinatal Project.8 Eighty percent of surviving children who had Apgar scores of 0 to 3 at 10 minutes or later (up to 20 minutes) were free of major handicap (CP, cognitive deficits, hearing loss, speech delay) at early school age. High rates of CP among survivors (57%) were found only when extended Apgar scores of 0 to 3 persisted to 20 minutes. These observations were often used to justify resuscitation of infants at birth for at least 20 minutes. More recently, the International Liaison Committee on Resuscitation (ILCOR) suggested that it may be justifiable to stop resuscitation if there are no signs of life after 10 minutes of continuous and adequate resuscitation.9 The ILCOR recommendation is based on more recent observational data10 of the outcome of infants with an Apgar of 0 at 10 minutes. Ten minutes of life and 10 minutes of effective resuscitation are typically not equivalent but represent the best available data for the ILCOR statement.
Present recommendations for shorter intervals of resuscitation suggest that newborn resuscitation techniques and/or obstetric surveillance during labor have changed the relationship between Apgar scores and mortality and/or morbidity. Results of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network Whole Body Cooling Trial11 provide an opportunity to reassess early childhood outcomes of infants with low Apgar scores at 10 minutes of age. We hypothesized that the Apgar score at 10 minutes is independently associated with death or disability at 18 to 22 months of age for near-term and term infants with encephalopathy of hypoxic-ischemic origin. This information may provide support for the ILCOR recommendation regarding resuscitation of infants with an Apgar score of 0 at 10 minutes.
This was an observational study that used data from the NICHD Neonatal Research Network randomized trial that compared whole-body hypothermia and current usual care.11 The trial was performed in 16 centers, and infants were enrolled after informed consent was obtained. Eligibility criteria included a gestational age of ≥36 weeks, postnatal age of ≤6 hours, and sequential fulfillment of specific physiologic and/or clinical criteria (acute perinatal event, acidemia within 1 hour of birth, low Apgar scores, and need for ventilation), followed by demonstration of moderate or severe encephalopathy by using a modification of the Sarnat stages.12 Exclusion criteria were major congenital abnormality, birth weight < 1800 g, or extremis condition.
Infants who were randomly assigned to whole-body cooling were positioned on a cooling/heating blanket attached to a Blanketrol II Hyper-hypothermia system (Cincinnati Sub-Zero [Cincinnati, OH]). The automatic-control mode was used to maintain an esophageal temperature of 33.5°C for 72 hours, followed by rewarming and subsequent temperature regulation according to the practices of each participating center. Infants who were randomly assigned to usual care were treated by using a radiant warmer that was initially servocontrolled to maintain abdominal skin temperature between 36.5°C and 37.0°C and to maintain core temperature. Subsequent adjustments of the servocontrol set point in response to core temperatures were made according to practices of each participating center. Treatment practices concerning ventilator management, intravenous fluid therapy, volume expansion, blood pressure support, treatment of seizures, and use of antibiotics all were per the discretion of the attending physician of each participating center.
Prospectively collected data regarding resuscitation at birth included Apgar scores at 1, 5, 10, and 20 minutes of age and delivery room variables (use of oxygen, bag mask ventilation, intubation, chest compressions, resuscitative medications, cord blood gases, and time to initiate spontaneous respiration). Maternal and infant characteristics were as previously detailed.11
The primary outcome was death or moderate/severe disability at 18 to 22 months of age.11 Trained personnel who were blinded to treatment group evaluated outcome by using standardized assessments. Disability was predefined as either severe or moderate. Severe disability included any of the following: Bayley II Mental Developmental Index (MDI) of <70, Gross Motor Functional Classification System level of 3 to 5, blindness, or a hearing deficit with amplification. Criteria for moderate disability were an MDI of 70 to 84 with any of the following: Gross Motor Functional Classification System level 2, persistent seizure disorder, or hearing deficit without amplification. Infants for whom a Bayley Scale of Infant Development could not be administered because of cognitive impairment were assigned a score of 49.
Of the 208 infants who were enrolled in the trial, 188 were included in this analysis. Three infants were lost to follow-up and thus were missing the primary outcome. Seventeen infants (7 outborn, 10 in-born) were missing the Apgar score at 10 minutes, 1 of whom was missing all Apgar scores. Apgar scores at 20 minutes were assigned to only 74 infants and, therefore, are not presented.
Correlations were explored between the Apgar score at 10 minutes and earlier assigned Apgar scores and acid-base status at birth. Logistic regression analysis and classification and regression-tree (CART) analysis were used to determine associations between the Apgar score at 10 minutes and the primary outcome. Logistic regression analysis was performed with and without adjustment for birth weight, gestational age, gender, outborn status, and treatment assignment (hypothermia versus usual care). Similar analyses were performed for the individual components of the primary outcome (death, moderate or severe disability). Associations between Apgar scores and outcomes are expressed as odds ratios (ORs) and 95% confidence intervals. CART method13 was implemented using CART software14 and used to identify the groups that were most likely to be at risk for death or neurodevelopmental impairment. The CART procedure seeks hidden structures in data by constructing a series of binary splits, called recursive partitioning. Splits are made to identify the most homogeneous subgroups with respect to the outcome. As in logistic regression, independent variables that are thought to be associated with the outcome are entered; the variables that are entered into the CART analysis were identical to the logistic regression analysis. The CART software selects variables in order of magnitude of improvement in prediction of the outcome, and the variables that contribute the most to the outcome are listed first at the top of the tree. Cross-validation is used to test the results of the model once the tree is grown. Only branches of the nodes of the tree that improve the correct classification of the tree survive the test. The area under the curve for CART analysis is analogous to area under the curve for logistic regression with higher values indicating better prediction. Results are expressed as means ± SD where appropriate.
The frequency distribution of Apgar scores at 1, 5, and 10 minutes for the 188 patients included in this observational cohort have been plotted (Fig 1). Eighty-nine percent of the infants had Apgar scores of 0 to 2 at 1 minute of age, and Apgar scores at 5 and 10 minutes were shifted to progressively higher values. Although not shown, there were no significant differences in the frequency distribution of Apgar scores between hypothermic and usual care groups. The birth weight and gestational age of this cohort were 3.4 ± 0.6 kg and 39 ± 2 weeks, respectively, and delivery room interventions consisted of the following: 100% of infants received oxygen, 97% received bag and mask ventilation, 96% of infants were intubated, 63% had chest compressions, and 57% of infants received resuscitative medications. Consistent with the need for resuscitation was acidemia (blood gas from umbilical cord or within the first postnatal hour) with a pH of 6.8 ± 0.2 and a base deficit of 19.5 ± 7.8 mEq/L.
The incidence of the primary outcome and its components (death, survival with moderate or severe disability) for each corresponding 10-minute Apgar score are listed in Table 1. In general, the incidence of the primary outcome increases with decreases in the 10-minute Apgar score; however, there seems to be a plateau at the lower end of Apgar scores with similar rates of the primary outcome for 10-minute Apgar scores of 0, 1, and 2. Results of the logistic regression to determine associations between the Apgar score at 10 minutes and the primary outcome and its components are listed in Table 2. An Apgar score at 10 minutes was associated with the primary outcome with and without adjustments for birth weight, gestational age, gender, outborn status, and treatment group; each point decrease in the Apgar score was associated with a 45% increase in the odds of death or disability. Similar associations were present for each of the components of the primary outcome. The covariate treatment group (hypothermia) lowered the odds of the primary outcome (OR: 0.44) and death alone (OR: 0.5). A reduction in death was not found in the NICHD trial11 and presumably reflects the exclusion of 20 infants with missing 10-minute Apgar scores. The logistic regression was also performed with inclusion of the 1- and 5-minute Apgar score in addition to the 10-minute Apgar score; when all 3 Apgar scores were included, only the 10-minute Apgar score and treatment group were associated with the primary outcome.
The CART model for prediction of death or moderate/severe disability is depicted in Fig 2. Apgar scores at 10 minutes determined the initial discrimination of the presence or absence of the primary outcome. Specifically, a 10-minute Apgar score of ≥5 is the first cut point with 65% of infants with an Apgar score of ≤4 having the primary outcome compared with 30% for those with higher Apgar scores. The next cut point is the treatment intervention (hypothermia), whereby 54% of infants had the primary outcome compared with 75% for infants with usual care. Of infants who received hypothermia, a 10-minute Apgar score of 3 or 4 was associated with the primary outcome in 44% compared with 71% for infants with a 10-minute Apgar score of ≤2. An Apgar score of 0 is not a cut point to provide additional discrimination of the primary outcome. Of infants with an Apgar score at 10 minutes of 3 or 4, the primary outcome is further discriminated by a birth weight of 3.2 kg (primary outcome present in 29% of those with a higher birth weight compared with 67% in those with a lower birth weight). The area under the curve for the CART analysis was 0.72 and was similar to the regression analysis.
An Apgar score of 0 at 10 minutes occurred for 25 infants, 12 of whom died. Of the 13 survivors, 6 were without moderate or severe disability at follow-up. The MDI of these 6 surviving infants was 87 ± 9 (range: 73–100). In contrast, the MDI of surviving infants with a moderate or severe disability that could be tested (n = 3) was 53 ± 6 (range: 49–59); 4 infants could not be tested and were assigned a score of 49.
The principal findings of this report are that (1) Apgar scores that were assigned at 10 minutes of age for infants who participated in the NICHD Neonatal Research Network hypothermia trial provided useful prognostic information, (2) death or moderate/severe disability is common with persistently low Apgar scores (<7) at 10 minutes of age, and (3) outcome of infants with an Apgar score of 0 at 10 minutes do not seem distinctly different from infants with an Apgar of 1 or 2. Seventeen infants were excluded because of missing 10-minute Apgar scores. Of these infants, 62% had Apgar scores at 5 minutes of ≥6; only 1 infant had an Apgar score of <3 (Apgar score of 1), and may account for failure to assign Apgar scores at 10 minutes. Analyses to examine the relationship between Apgar scores at 10 minutes and death or disability at 18 to 22 months were adjusted for demographic characteristics (birth weight, gestational age, and gender), outborn status, and the treatment intervention. Analyses were performed in this manner to assess whether Apgar scores are helpful to clinicians before a neurologic examination, determination of extent of encephalopathy, brain electrophysiologic and imaging studies, and other clinical or laboratory parameter that may indicate prognosis.
The relationship between Apgar scores and early childhood outcome has been the subject of intense interest. Both the American Academy of Pediatrics and the American College of Obstetrics and Gynecology have cautioned against prediction of later neurologic dysfunction solely on the basis of low Apgar scores at 5 minutes.15 This reflects the low prevalence of extremely low Apgar scores (0–3) despite the high relative risk for death or CP with such low Apgar scores. These observations are based on population cohort studies that used national registries to link Apgar scores with outcome in Scandinavia.16–18 Very low Apgar scores of 0 to 3 at 5 minutes of age have greater prognostic value when combined with peripartum complications, fetal acidemia, and signs of neonatal encephalopathy.19–21
Between 1959 and 1966 infants with a birth weight of >2.5 kg and Apgar scores of 0 to 3 at 10 minutes (latest Apgar score in this range) had rates of mortality at 1 year and CP at 7 years of 18.0% and 4.7%, respectively.8 Since that era, there are limited data on early childhood outcome of infants with Apgar scores assigned at 10 minutes of age. The long-term outcome of infants with an Apgar score of 0 at 10 minutes and successfully resuscitated to be admitted to a NICU has been summarized by Harrington et al.10 This is a retrospective experience that yielded 94 infants on the basis of either population data or cohort studies that spanned 35 years with the earliest report using infants who were born between 1965 and 1975 and the most recent based on infants who were born between 1991 and 2004.10,22–28 Four of the 8 reports are based on infants who were born in the 1980s and 1990s, and only the data from Harrington et al10 include infants who were born beyond 2000. Of the 94 infants identified with an Apgar of 0 at 10 minutes, 78 died, 12 survived with severe or moderate disability, 1 had a mild disability, and 3 were lost to follow-up. Thus, death or disability (moderate or severe in extent) occurred in 95% of infants with an Apgar score of 0 at 10 minutes. The earlier observational studies within the study of Harrington et al10 form the basis for the ILCOR recommendation regarding discontinuation of resuscitation after 10 minutes of adequate resuscitation.9 None of the previous reports included infants who had been subjected to hypothermia, which is being increasingly used for these infants. Important limitations to the outcome data for infants with an Apgar score of 0 at 10 minutes includes retrospective data collection, inclusion of preterm and term infants, unclear exclusion criteria, variable duration of outcome, lack of consistency in outcome measures, and difficulty in determining the adequacy of resuscitation.
In contrast, the results from the NICHD Neonatal Research Network hypothermia trial differ for the outcome of infants with an Apgar score of 0 at 10 minutes. Although death or disability is very high (76%; Table 1) similar to retrospective reports, the outcome of survivors was more heterogeneous; 6 of the 13 survivors had either a mild or an absent disability at an 18- to 22-month assessment. The unadjusted outcome of infants with an Apgar score of 0, 1, or 2 at 10 minutes seems similar (Table 1), although an Apgar score of ≤2 in the CART analysis is a cut point for death or disability only for the infants who underwent hypothermia. These observations are based on a large contemporary cohort of infants with a uniform gestational age (≥36 weeks), prospective data collection, and a standardized, rigorous follow-up program with examiners trained to reliability, uniform assessment tools and a low attrition rate at follow-up.
The decision of when to terminate resuscitative efforts for newborn infants after birth is difficult. The outcome of infants with an Apgar score of 0 at 10 minutes derived from reports during the past 20 years seems to have been the best available data to guide resuscitative efforts. The results of this analysis add new observations to the outcome of infants with an Apgar score of 0 at 10 minutes and raise concern regarding the ILCOR/NRP recommendation to consider discontinuation of resuscitation when there are no signs of life. These new observations are based on infants who qualified for the NICHD Neonatal Research Network randomized trial of therapeutic hypothermia and may not be applicable to all infants with an Apgar score of 0 at 10 minutes. Data are not available on the adequacy of resuscitative efforts or the number of infants who were admitted to NICUs and were deemed too sick to approach for study entry or died before enrollment. These factors may result in an overestimation of the rate of intact survival among infants with an Apgar score of 0 at 10 minutes. In addition, the assessment of neurodevelopmental outcome may change later in childhood.29 Nevertheless, caution is warranted before adopting a defined time interval to guide the duration of resuscitation.
The Hypothermia Study Group
Case Western Reserve University: Rainbow Children's Hospital (principal investigator: Avroy A. Fanaroff, MD; co–principal investigator: Michele C. Walsh, MD; study coordinator: Nancy Newman, BA, RN; follow-up principal investigator: DeeAnne Wilson-Costello, MD; and follow-up coordinator: Bonnie Siner, RN); Brown University: Women & Infant's Hospital (principal investigator: William Oh, MD; study coordinator: Angelita Hensman, BSN, RNC; follow-up principal investigator: Betty Vohr, MD; and follow-up coordinator: Lucy Noel, RN); Duke University (principal investigator: C. Michael Cotten, MD; study coordinator: Kathy Auten, BS; follow-up principal investigator: Ricki Goldstein, MD; and follow-up coordinator: Melody Lohmeyer, RN); Emory University: Grady Memorial Hospital and Crawford Long Hospital (principal investigator: Barbara J. Stoll, MD; co–principal investigator: Lucky Jain, MD; and study coordinator: Ellen Hale, RN, BS); Indiana University: Riley Hospital for Children and Methodist Hospital (principal investigator: James A. Lemons, MD; study coordinators: Diana Dawn Appel, RN, BSN, and Lucy Miller, RN, BSN; follow-up principal investigator: Anna Dusick, MD; and follow-up coordinator: Leslie Richard, RN); Stanford University (principal investigator: David K. Stevenson, MD; co–principal investigator: Krisa VanMeurs, MD; study coordinator: M. Bethany Ball, BS, CCRC; and follow-up principal investigator: Susan R. Hintz, MD); University of Alabama at Birmingham: University Hospital-UAB (principal investigator: Waldemar A. Carlo, MD; study coordinator: Monica Collins, RN, BSN, Shirley Cosby, RN, BSN; follow-up principal investigator: Myriam Peralta-Carcelen, MD; and follow-up coordinator: Vivien Phillips, RN, BSN); University of Cincinnati: University Hospital, Cincinnati Children's Hospital Medical Center (principal investigator: Edward F. Donovan, MD; study coordinators: Cathy Grisby, BSN, Barb Alexander, RN, Jody Shively, RN, and Holly Mincey, RN; follow-up principal investigator: Jean Steichen, MD; and follow-up coordinator: Teresa Gratton, PA); University of California-San Diego: UCSD Medical Center and Sharp Mary Birch Hospital for Women (principal investigator: Neil N. Finer, MD; co–principal investigator: David Kaegi, MD; study coordinators: Chris Henderson, CRTT, Wade Rich, RRT-NPS, and Kathy Arnell, RN; follow-up principal investigator: Yvonne E. Vaucher, MD, MPH; and follow-up coordinator: Martha Fuller, RN, MSN); University of Miami (principal investigator: Shahnaz Duara, MD; study coordinator: Ruth Everett, BSN; and follow-up principal investigator: Charles R. Bauer, MD); University of Rochester: Golisano Children's Hospital at Strong (principal investigator: Ronnie Guillet, MD, PhD; study coordinator: Linda Reubens, RN; follow-up principal investigator: Gary Myers, MD; and follow-up coordinator: Diane Hust, RN); University of Texas Southwestern Medical Center at Dallas: Parkland Hospital (principal investigator: Abbot R. Laptook, MD; study coordinators: Susie Madison, RN, Gay Hensley, RN, Nancy Miller, RN; follow-up principal investigator: Roy Heyne, MD, Sue Broyles, MD; and follow-up coordinator: Jackie Hickman, RN); University of Texas–Houston: Memorial Hermann Children's Hospital (principal investigator: Jon E. Tyson, MD, MPH; study coordinator: Georgia McDavid, RN, Esther G. Akpa, RN, BSN, Claudia Y. Franco, RN, BNS, MSN, NNP, Patty A. Cluff, RN, and Anna E. Lis, RN, BSN; and follow-up principal investigators: Brenda H. Morris, MD, and Pamela J. Bradt, MD, MPH); Wayne State University: Hutzel Women's Hospital & Children's Hospital of Michigan (principal investigator: Seetha Shankaran, MD; study coordinators: Rebecca Bara, RN, BSN, Geraldine Muran, RN, BSN; follow-up principal investigator: Yvette Johnson, MD; and follow-up coordinator: Debbie Kennedy, RN); and Yale University: New Haven Children's Hospital (principal investigator: Richard A. Ehrenkranz, MD; study coordinator: Patricia Gettner, RN; and follow-up coordinator: Elaine Romano, RN). NICHD Neonatal Research Steering Committee: Brown University: William Oh, MD; Case Western University: Avroy A. Fanaroff, MD; Duke University: Ronald N. Goldberg, MD; Emory University: Barbara J. Stoll, MD; Indiana University: James A. Lemons, MD; Stanford University: David K. Stevenson, MD; University of Alabama at Birmingham: Waldemar A. Carlo, MD; University of Cincinnati: Edward F. Donovan, MD; University of California at San Diego: Neil N. Finer, MD; University of Miami: Shahnaz Duara, MD; University of Rochester: Dale L. Phelps, MD; University of Texas–Dallas: Abbot R. Laptook, MD; University of Texas–Houston: Jon E. Tyson, MD, MPH; Wake Forest University: T. Michael O'Shea, MD, MPH; Wayne State University: Seetha Shankaran, MD; Yale University: Richard A. Ehrenkranz, MD; and Chair, Alan Jobe, University of Cincinnati. Data Coordinating Center (RTI International): principal investigator: W. Kenneth Poole, PhD; coordinators: Betty Hastings and Carolyn M. Huitema Petrie, MS. Eunice Kennedy Shriver National Institute of Child Health and Human Development: program scientists: Rosemary D. Higgins, MD, and Linda L. Wright, MD; and coordinator: Elizabeth McClure, Med. Data safety and monitoring committee: Children's National Medical Center: Gordon Avery, MD; Columbia University: Mary D'Alton, MD; RTI International: W. Kenneth Poole, PhD (ex officio); University of Virginia: John C. Fletcher, PhD (deceased); University of Washington: Christine A. Gleason, MD; and University of Pittsburgh: Carol Redmond, PhD.
This study was supported in part by grants Case Western Reserve University U10 HD21364, University of Texas–Houston U10 HD21373, Wayne State University U10 HD21385, University of Miami U10 HD21397, Emory University U10 HD27851, University of Cincinnati U10 HD27853, Indiana University U10 HD27856, Yale University U10 HD27871, Stanford University U10 HD27880, Brown University U10 HD27904, University of Alabama at Birmingham U10 HD34216, RTI U10 HD36790, University of California–San Diego U10 HD40461, Duke University U10 HD40492, Wake Forest University U10 HD40498, University of Rochester U10 HD40521, University of Texas Southwestern Medical Center at Dallas U10 HD40689, General Clinical Research Centers grants GCRC M01 RR30, GCRC M01 RR39, GCRC M01 RR44, GCRC M01 RR70, GCRC M01 RR80, GCRC M01 RR633, GCRC M01 RR750, GCRC M01 RR6022, GCRC M01 RR7122, GCRC M01 RR8084, and GCRC M01 RR16587.
- Accepted July 9, 2009.
- Address correspondence to Abbot R. Laptook, MD, Women & Infants’ Hospital of Rhode Island, 101 Dudley St, Providence, RI 02906. E-mail:
Financial Disclosure: The authors have indicated they have no financial relationships relevant to this article to disclose.
What's Known on This Subject:
ILCOR and NRP have made recommendations for the duration of cardiopulmonary resuscitation on the basis of literature of infants with an Apgar score of 0 at 10 minutes. This literature is retrospective, and much of it is dated and without systematic follow-up.
What This Study Adds:
This study contributes new data on infants with low Apgar scores at 10 minutes (some with a value of 0) by using data from a randomized trial that included systematic follow-up. The results raise questions regarding NRP recommendations.
- ↵American Academy of Pediatrics; American Heart Association. Neonatal Resuscitation Textbook. 5th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2006
- ↵Nelson KB, Ellenberg JH. Apgar scores as predictors of chronic neurologic disability. Pediatrics.1981;68 (1):36– 44
- ↵The International Liaison Committee on Resuscitation (ILCOR) consensus on science with treatment recommendations for pediatric and neonatal patients: neonatal resuscitation. Pediatrics.2006;117 (5). Available at: www.pediatrics.org/cgi/content/full/117/5/e978
- ↵Breiman L, Friedman JH, Olshen RA. Classification and Regression Trees. Belmont, CA: Wadsworth; 1984
- ↵Steinberg D, Colla P. Classification and Regression Tree: Supplementary Manual for Windows. San Diego, CA: Salford Systems; 1997
- ↵American Academy of Pediatrics, Committee on Fetus and Newborn; American College of Obstetricians and Gynecologists and Committee on Obstetric Practice. The Apgar score. Pediatrics.2006;117 (4):1444– 1447
- ↵Moster D, Lie RT, Markestad T. Joint association of Apgar scores and early neonatal symptoms with minor disabilities at school age. Arch Dis Child Fetal Neonatal Ed.2002;86 (1):F16– F21
- ↵Freeman JM, Nelson KB. Intrapartum asphyxia and cerebral palsy. Pediatrics.1988;82 (2):240– 249
- Casalaz DM, Marlow N, Speidel BD. Outcome of resuscitation following unexpected apparent stillbirth. Arch Dis Child Fetal Neonatal Ed.1998;78 (2):F112– F115
- ↵Nelson KB, Ellenberg JH. Children who “outgrew” cerebral palsy. Pediatrics.1982;69 (5):529– 536
- Copyright © 2009 by the American Academy of Pediatrics