Heather Mohay

SCHOOL PERFORMANCE OF ELBW CHILDREN: A CONTROLLED STUDY

This paper examines the prevalence of learning difficulty in reading, spelling, mathematics and writing and the prevalence of attention deficit disorder (ADD) in extremely low‐birthweight (ELBW) children at school compared to their peers. Parents of 87 eligible ELBW children completed an educational questionnaire and questionnaire for ADD. Teachers of the ELBW children completed a detailed educational and ADD questionnaire for the study child and two control children in the same class, matched for âge and nearest in birth date to the study child.

Executive function of children with extremely low birthweight: a case control study.

This study examines the executive function (EF) skills of extremely‐low‐birthweight (ELBW) children at school compared with their peers. Thirty children with ELBW and 50 control children (both with a mean age of 62 ±4 months) were administered tests of EF including the Tower of Hanoi task, Finger Sequencing task, and Tapping Test. Children with ELBW, including those who scored more than 1 SD below the mean on the Peabody Picture Vocabulary Test – Revised, scored significantly lower than their peers on all executive tasks. There was limited correlation between EF and previous general quotient index scores obtained at routine assessment using the McCarthy Scales of General Ability at 4 years of age for the children with ELBW. Results suggest that children with ELBW are at risk for deficits in‘executive’behaviours including planning, sequencing, and inhibition which may have implications for later learning.

Gender differences in cognitive abilities at 2 years in ELBW infants

Gender differences in cognitive abilities exist for children born at term. For very preterm infants uncertainty exists regarding the presence and extent of such differences and their relationship to perinatal brain injury and neurological impairment. This study examined gender differences in cognitive abilities in a cohort of 336 extremely low birth weight (ELBW) infants at 2 years corrected age. Infants were classified as at low or high perinatal risk at birth according to four perinatal risk factors. A subgroup of 33 neurologically impaired infants was identified. Outcome at 2 years was measured by the overall General Quotient (GQ) on the Griffiths scale and its five subscale scores. Female ELBW children were superior to male ELBW children by 4.1 GQ points (95% CI 1.0, 7.1). If the impaired subgroup was excluded, the difference in GQ was 3.2 points (95% CI 0.4, 5.6), and this difference was predominantly due to female infants being superior in the hearing and speech subscale (6.0 points, 95% CI 2.6, 9.5). These differences were relatively independent of perinatal risk status. Gender differences in the Griffiths GQ for ELBW infants are similar to expected differences for term infants and are unlikely to cause substantial bias in interpreting outcome studies for ELBW infants, unless these involve tests of specific cognitive abilities such as language.

Perinatal hypoxic-ischaemic brain injury-prediction of outcome

Twenty‐sis term babies with hypoxic‐ischaemic brain injury were studied during the neonatal period to evaluate the prediction of outcome to at least one year of age by means of ultrasonography, CT scanning and Doppler ultrasound assessment of cerebral palsy blood flow velocity (CBFV). Adverse outcome was defined as the occurrence of cerebral palsy, developmental delay or death. At follow‐up, 17 infants had an adverse outcome (seven died, 10 had disability); the remainder had no detectable impairment. Abnormalities on cranial ultrasound were not, but generalised decreased tissue density on CT scan was, associated with adverse outcome. Abnormal mean CBFV in the middle cerebral artery had no association with outcome, but abnormal mean CBFV in the anterior cerebral artery and a low resistance index in both arteries were significantly associated with adverse outcome. Such information may be used for appropriate counselling of parents of asphyxiated infants.

The prevalence and origins of left hand preference in high risk infants, and its implications for intellectual, motor and behavioural performance at four and six years.

This study investigates the origins of hand preference at 4 years in a cohort of 115 high risk and premature infants; the relationship between patterns of hand preference and intellectual, motor, temperament and behavioural status at 4 and 6 years; and evidence for brain injury in mediating the relationship between hand preference and development disorder. Increased left hand preference was independently associated with extreme prematurity, high neonatal risk, increased numbers of minor physical anomalies, lowered intellectual and motor abilities, and more difficult temperament. These findings supported the presence of intrauterine and neonatal pathological mechanisms leading to left hand preference in a small number of children. Neither poor function of the non dominant hand nor absence of a family history of left handedness could further define this pathological subgroup. Support for pathological mechanisms producing left handedness was found predominatly in the infants of high birth weight, whereas prevalence of left handedness was increased mainly among the extremely low birth weight infants. In this latter group the prevalence of left handedness was also increased among children of normal intelligence, suggesting that mechanisms other than brain damage lead to left hand preference in very premature infants.

Changing patterns of survival and outcome at 4 years of children who weighed 500–999 g at birth

To evaluate the impact of changing perinatal practices on survival rates and 4 year neurodevelopmental outcome for infants of birthweight 500–999 g.

Handedness in Extremely Low Birth Weight Infants: Aetiology and Relationship to Intellectual Abilities, Motor Performance and Behaviour at Four and Six Years

Hand preference was measured in a total group of 71 ELBW children to determine patterns of hand preference at 4 and 6 years, possible aetiological factors leading to handedness, and whether left or non right hand preference were markers for intellectual, motor, temperament or behavioural differences. At both 4 and 6 years the prevalence of left handedness was increased, though this prevalence changed over the period of the study. Results supported brain injury as one mechanism leading to increased left hand preference, though this process did not adequately explain this increase. Possible reasons for this and the apparent change in prevalence with time are examined. Mixed handedness at 4 years was associated with lower intellectual abilities though otherwise children were similar in motor skills, temperament and behaviour independent of hand preference category.

Executive Function in 7–9-Year-Old Children Born Extremely Preterm or with Extremely Low Birth Weight: Effects of Biomedical History, Age at Assessment, and Socioeconomic Status

Forty-five children born extremely preterm and/or with extremely low birth weight (ELBW), who were of average intelligence, were assessed at age 7-9 on a raft of measures of executive function (EF) designed to assess inhibition, set shifting, planning, fluency, and working memory. Relative to 45 full-term controls, the preterm/ELBW children showed reliable impairments of inhibition, fluency, and working memory. Among the 7-year olds, the preterm/ELBW group also showed significantly worse set shifting. After controlling for age and family socioeconomic status (SES), within-group analyses of the preterm/ELBW data revealed that higher birth weights were associated with better inhibition, whereas lower neurobiological risk (gauged by such aspects of neonatal medical history as a number of days on oxygen) was associated with better planning. Moreover, there were interactions between neurobiological risk and SES on the measures of inhibition, fluency, and working memory, indicating that the adverse effects of risk were greater among children from low-income households. These findings demonstrate that neonatal medical problems are associated with considerable variability in EF among normally developing preterm/ELBW children and implicate an important influence of the family environment on the maturation of EF.

The influence of growth on development outcome in extremely low birthweight infants at 2 years of age

Objective: To determine if weight <3rd and <10th centile at 2 years in extremely low birthweight (ELBW) infants is associated with problems of development and motor skills, and whether this association is explained by perinatal risk status.

Characteristics at four months follow-up of infants born small for gestational age: a controlled study

This prospective study compared 65 small-for-gestational-age (SGA) (birth weight < 3rd centile) and 71 control infants at a corrected age of 4 months. It was hypothesised that differences would exist in growth, development, temperament and minor neurological signs and that these would be predicted by type (proportional/disproportional) of growth restriction at birth and maternal mood disturbance at birth or at 4 months. Infants had a Griffiths developmental test and neuromotor assessment. Maternal mood and infant temperament were surveyed. Few differences were found between SGA and control infants. SGA infants showed catch-up growth with 63% being above the third percentile and 43% being above the tenth percentile for weight. SGA infants had lower Griffiths GQ scores (97 vs. 102, P = 0.02) and they were rated in temperament as more manageable than controls. There were no differences in subtle neuromotor signs. Neither type of SGA nor maternal mood disturbance at birth had prognostic significance for infant catch up growth, neuromotor scores, or temperament though level of maternal stress and anxiety at 4 months were related to lower GQ scores in SGA infants.