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;

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 various parameters.

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 analysis.

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.

TABLE I

MISIC Score (Mean ±SD) at 12 Years of Age in Children with Hypoxic Ischemic Encephalopathy 

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.

TABLE II

Association Between IQ and Severity of HIE

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 behavior problems.

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 attainment targets(9).

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.

Funding: None.

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