Indian Pediatr Suppl 2009;46: S67-S70
Hypoxic Ischemic Encephalopathy –
Developmental Outcome at 12 Years
Babu George, MS Razeena Padmam*, MKC Nair, MS Indira, K
Syamalan and J Padmamohan
From Child Development Centre, Medical College,
Thiruvananthapuram, Kerala, India;
and *School of Behavioural Sciences, MG University, Kottayam, Kerala,
Correspondence to: Dr MKC Nair, Professor of Pediatrics
and Clinical Epidemiology and, Director,
Child Development Centre, Medical College, Thiruvananthapuram 695 011,
This study was done to determine the mental and motor
development and developmental psychopathology problems at 12 years of
age, among term babies with hypoxic ischemic encephalopathy (HIE) at
birth. 48 children with HIE at birth were assessed at 12 years of age,
to find out the developmental status. Among 41 children, who had grade I
HIE at birth, 15 (36%) had normal intelligence and only 4 (9.8%) had
mental retardation. Among the rest of 7 babies who had grade 2 and 3
HIE, 2 children had mental retardation, 3 had borderline IQ and 2 had
low average IQ. Hyperkinesis (23%) and somatic disorders (17%) were the
commonest developmental psychopathology problems among all the three
grades of HIE together. There was also an increased incidence of visual
abnormality, cerebral palsy and various psychopathology problems in
children who had grade 2 and 3 HIE.
Key words: Developmental outcome, Hypoxic Ischemic Encephalopathy
(HIE), Psychopathology problems.
Perinatal hypoxia has been recognized as a
possible cause of mental and physical handicaps in childhood for more than
100 years. Hypoxic ischemic encephalopathy (HIE) is the most important
consequence of perinatal hypoxia(1). Perinatal hypoxia including birth
asphyxia leading to HIE has immediate and long-term consequences to the
baby. Perinatal hypoxia remains a major cause of acute perinatal brain
injury, leading ultimately to neurologic dysfunction, which manifests as
cerebral palsy, mental retardation, and epilepsy(2). Between 8-17% of all
cerebral palsy is associated with adverse perinatal events suggestive of
asphyxia(3). Sequelae include motor problems, subnormal mental development
including speech and language delay, seizures, poor hearing or deafness,
and poor vision. Perinatal brain damage has been reported to account for
57.5% of all neonatal deaths, 30% of admissions to a special care nursery,
and 12.5% of mental retardation, epilepsy and cerebral palsy at the age of
Neural damage affects the cognitive development of the
individual impairing the ability to learn, talk, read, calculate,
memorize, conceptualize, organize, pay attention, interact socially and
behave appropriately. Some problems that appear more slowly are more
difficult to detect, and may not be obvious until preschool or school age.
They may present as poor coordination, scholastic backwardness, specific
learning disability, very short attention span, behavioural problems,
hyperactivity, etc. The present study assessed the developmental outcome
at 12 years of age for babies who had HIE due to birth asphyxia.
We included 48 children with various grades of HIE at
birth, who reported for assessment of developmental status at 12 years of
age at Child Development Centre (CDC). The following tools were used in
this study, to measure the developmental outcome;
(i) Malin’s Intelligence Scale for Indian
Children (MISIC) for measuring intelligence quotient and also for
deriving verbal IQ, performance IQ and full scale IQ(5).
(ii) The Indian adaptation of Vineland Social
Maturity Scale (VSMS) to measure the social quotient (SQ) of the
(iii) Developmental Psychopathology Checklist
(DPCL) for children, to measure developmental and psychopathology
problems using cut off scores as per interpretation and instructions of
the checklist (7).
(iv) Pure tone audiometry to find out hearing
(v) Snellen chart for vision assessment.
(vi) Clinical assessment was adopted to detect
motor delay (cerebral palsy).
A consultant child psychologist administered the
psychological tests. All children were examined in detail by a consultant
pediatrician. The data quality was checked and analysis was done using
SPSS to assess the consistency, relationships and differences among
Among 48 children who reported for follow up at 12
years, 41(85.4%) children had Grade 1 HIE, 5 (10.4%) had Grade 2 HIE and 2
children (4.2%) had Grade 3 HIE. Since the number of cases in Grade 2 and
3 HIE were less, these two groups were pooled together for statistical
Among the total respondents, 45.8% children were born
to mothers with high-risk pregnancy. Majority of children (60.4%) were
delivered by cesarean section or vacuum suction. There was a history of
fetal distress in the antenatal period in 29.2% children. All babies were
born at full term and 79.2% babies had weight appropriate for gestational
age. 18.8% were born as small for gestational age and only one child (2%)
was born large for gestational age. Malin’s Intelligence Scale for Indian
Children (MISIC) could be administered in 46 children since two children
(one child each in Grade 2 and 3 HIE) had very low intelligence and hence
could not be assessed. The IQ of these children was assessed by Seguin
Form Board (SFB) test. Table I shows the full scale
IQ according to MISIC norms.
MISIC Score (Mean ±SD) at 12 Years of Age in Children with Hypoxic Ischemic Encephalopathy
MISIC sub tests
MISIC Score (Mean
Grade 1 HIE
Grade 2 and 3 HIE
Full Scale IQ
MISIC – Malin’s Intelligence Scale
for Indian Children;
IQ – Intelligence quotient
Table II demonstrates that children having
average and above average IQ level are absent among children of Grade 2
and 3 HIE. The social quotient of children measured using Vineland Social
Maturity Scale (VSMS) revealed that there was a decline in the social
quotient of Grade 2 and 3 HIE group (mean 108.62, SD 24.6) as against
(mean 115.94, SD 0.90) among Grade1 HIE.
Association Between IQ and Severity of HIE
IQ level at
Grade 2 and
Below 69 (mentally retarded)
80-89 (low average)
90-109 (average and above)
Chi square= 5.01, d.f. =3, P>0.005
There was a statistically significant higher prevalence
of developmental delay, developmental problems/disorders, learning
disorder and somatic disorder among HIE Grade 2 and 3, but no
statistically significant difference was observed for hyperkinesis,
conduct disorder and emotional disorder. Obsessive compulsive neurosis and
psychosis were not observed in both the groups. The observation that
learning disorder was present only among 2.4% of Grade 1 HIE group as
against 43% of Grade 2 and 3 HIE group is clinically important, because
85.4% of HIE in the study sample belonged to Grade 1. Multiple behavioral
problems were observed in 6 (14.6%) children with HIE 1 as compared to
4(57%) in children with HIE 2 and 3 (P 0.001). Hearing
abnormalities were similar in two groups (HIE 1: 1/41 (2%); HIE 2 and 3:
1/7 (14%); P=0.27). Motor delay and visual problems were seen in 2
(29%) and 3(43%) children in the HIE 2 and 3 group, respectively. When
verbal IQ was considered as independent variable and performance
IQ/full-scale IQ was considered as dependant variable, the correlation
coefficient was significant (P <0.001). Similarly, a strong
correlation was observed between performance IQ and full scale IQ. On the
contrary, social quotient (SQ) showed a strong negative correlation with
The results of this study showed that Grade 1 HIE had a
good prognosis and Grade 2 & 3 had poor outcome on all parameters at 12
years of age. The findings of this study is in agreement with recent
reports of late outcome of neonatal encephalopathy. In a study by Marlow,
et al.(9), out of 65 children with neonatal encephalopathy
evaluated at 7 years, disability was present in 6% of the moderate and 42%
of the severe encephalopathy group. In particular, memory and
attention/executive functions were impaired in the severe group. Despite
relatively small differences in performance of the moderate group, special
educational needs were identified more often in both encephalopathy
groups, associated with lower achievement on national curriculum
Robertson, et al.(10) demonstrated that of 145
children with neonatal encephalopathy (56 mild, 84 moderate and 5 severe)
tested for school performance at 8 years of age, the incidence of
impairment, which included cerebral palsy, blindness, cognitive delay,
convulsive disorder, and severe hearing loss, was 16%. Intellectual,
visual-motor integration, and receptive vocabulary scores, as well as
reading, spelling, and arithmetic grade levels for those with moderate or
severe encephalopathy, were signifi-cantly below (P<0.01) those in
the mild encephalo-pathy or peer comparison groups. Nonimpaired survivors
of moderate encephalopathy were more likely to be more than one grade
level delayed than were children from the peer group (reading 35% vs 15%,
spelling 18% vs 8%, arithmetic 20% vs 12%, respectively; P<0.01).
Thus, children who had moderate and severe neonatal encephalopathy are at
risk for physical and mental impairment and reduced school performance.
Children with mild encephalo-pathy had school performance scores similar
to those of their peers(10). The limitation of the study was that there
were only 5 children with Grade 2 & 3 HIE.
The observation that 1/3rd (31%) of children who had
HIE in the neonatal period had normal IQ is a striking observation and
supports the concept that birth asphyxia is not the only cause for mental
retardation and cerebral palsy. The increased incidence of visual and
motor disability and develop-mental psychopathology problems, especially
among children who had severe grades of HIE highlights the need for early
intervention. The observation that the prognosis of babies who had HIE
grade 1 is good can be utilised for counseling parents and offering them a
positive outlook towards their child’s neurodevelopmental outcome.
Dr Zulfikar Ahamed, SAT Hospital and, Mr N Asokan,
Child Development Centre, Medical College, Thiruvananthapuram.
Contributors: BG, MSRP, MKCN were involved in
designing the study and preparation of the manuscript and will act as
guarantor. MSI and JP were involved in the data collection and, KS was
involved in the analysis of data.
Competing interests: None stated. The findings and
conclusions of this report are those of the authors and do not necessarily
represent the views of the funding agency.
What This Study Adds?
• Children who had suffered from Grade 1 HIE at
birth have a better prognosis as compared to those with grade 2 and
3 HIE with regard to full scale IQ and verbal IQ at 12 years of age.
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