Neurological outcome in high risk weight appropriate for gestational age preterm children at early school age

A gradient relationship between low birth weight and IQ: A meta-analysis

Multiple studies have reported that individuals with low birth weights (LBW, <2500 g) have a lower intelligence quotient (IQ) than those with normal birth weights (NBW, ≥2500 g). Based on 57 eligible individual studies including 12,137 participants, we performed a meta-analysis to estimate the association between low birth weight and individuals' IQ scores (IQs). The pooled weight mean difference (WMD) in IQs between NBW and LBW individuals was 10 (95% CI 9.26-11.68). The WMD was stable regardless of age. No publication bias was detected. The mean IQs of the extremely low birth weight (ELBW, <1000 g), very low birth weight (VLBW, 1000-1499 g), moderately low birth weight (MLBW, 1500-2499 g) and NBW individuals were 91, 94, 99 and 104, respectively. Additionally, the WMD in IQs with NBW were 14, 10 and 7 for ELBW, VLBW, and MLBW individuals, respectively. Two studies permitted estimates of the influence of social determinants of health to the discrepancy in IQs, which was 13%. Since IQ is inherited and influenced by environmental factors, parental IQs and other factors contribute to residual confounding of the results. As the conclusion was based on population studies, it may not be applicable to a single individual.

[Neurodevelopmental outcome of premature infants born at less than 33 weeks of gestational age and not cerebral palsy at the age of 5 years]

AIM

To appreciate the impact of prematurity, fetal hypotrophy and familial environment on the neurodevelopmental performances of very premature infants without cerebral palsy at the age of five years.

POPULATION AND METHODS

We followed a regional cohort of 171 very premature infants (< or = 32 weeks of gestation) until they were five years of age. Cognitive functions were tested with the WPPSI test and the development quotient was assessed by the ability to draw a "bonhomme". Twenty-two premature infants suffered from cerebral palsy diagnosed before the age of two years. Another infant had a moderate diplegia at the five-year examination. We had no information for 16 prematures (9.3% of survivors). Twenty-eight premature infants were considered as having no severe disability on phone or mailed contact, and another child had a severe isolated mental retardation. We examined 104/148 infants, and 96/148 survivors without cerebral palsy passed the tests. The cognitive functions of these premature infants are compared to the performances of a control group made up of 108 children born at term > or = 37 weeks, matched for birthplace and single or twin characteristics of the pregnancy.

RESULTS

The values of the different quotients are significantly decreased in the preterm group. The global IQ and the performance IQ are 0.8 SD, verbal IQ is 0.5 SD and the development quotient is 0.4 SD below the values observed in the control group. A performance IQ less than -2 SD for the mean of the control group is observed three times more than in the controls (13.5% vs 3.7%, P < 0.01). Multiple linear regression shows that prematurity explains, independent of hypotrophy and socioeconomic environment, 8% of the variation of the performance IQ (P < 0.01), 2% of the variation of the verbal IQ and 2% of the development quotient (P < 0.05).

CONCLUSION

The five-year neurologic outcome of the children born prematurely in this regional study is similar to the results observed in regional studies conducted in Europe: 13.4% of the survivors have cerebral palsy, and the cognitive functions of the children with no cerebral palsy are significantly lower than the term control group. Other risk factors such as hypotrophy, which modulates the developmental quotient, and the socioeconomic status, which modulates the verbal IQ, are underlined.

Visual-motor function of very low birth weight and full-term children at 3 1/2 to 4 years of age

Improvements in perinatal and neonatal management have not only led to a higher survival rate of very low birth weight infants (VLBW; < or = 1,500 g or < 32 weeks gestational age), but also to a better outcome of these children. However the percentage of VLBW children who need special education because of later school problems remains high even in children considered neurologically normal during infancy. We assessed 40 VLBW children and 83 healthy full-term children at age 3 to 4 years by means of a simple and short test for visual-motor deficits. The test included the copying and cutting-out of geometric shapes, the building of models, the recognition of colours and the observation of the concentration and cooperation during the test. All VLBW children had had a good perinatal outcome and had been considered neurologically normal at one year of age. Most VLBW children scored within 1 standard deviation (S.D.) of the test mean, but on average the VLBW children scored significantly lower than the full-term infants in the copying of figures, the cutting-out of geometric forms, the building of models and in the overall concentration and cooperation during the test. Children who attended a nursery school achieved significantly better test results. Girls tended to have better results, but this was not statistically significant. Social factors and age had a significantly greater impact on results than perinatal factors. In summary, VLBW children scored significantly less in almost every test item compared to their term peers. Our test battery could serve as a short introductory test to screen for deficits in visual-motor skills, especially in VLBW children.

Periventricular leucomalacia and preterm birth have different detrimental effects on postural adjustments

Postural adjustments during sitting on a moveable platform were assessed by means of multiple surface EMGs of neck, trunk and leg muscles and kinematics in three groups of children, aged 1 1/2-4 1/2 years. The first group consisted of 13 preterm children (born at a gestational age of 25-34 weeks), whose neonatal ultrasounds had shown distinct lesions of the periventicular white matter (PWM). The second group was the preterm control group, consisting of 13 preterm children with normal neonatal brain scans, matched to the PWM group with respect to gestational age at birth, birth weight, sex and age of postural assessment. The third group was formed by 13 healthy children born at term and matched to the PWM group with respect to sex and age at examination. In addition to the postural assessment an age-specific neurological examination was carried out. Three of the children of the PWM group developed a cerebral palsy syndrome, nine showed minor neurological dysfunction and one child was neurologically normal. In the preterm control group one child showed minor neurological dysfunction, while the remaining 12 children of this group and all children of the full-term group were neurologically normal. The postural assessment revealed that preterm birth was associated with two types of postural dysfunction. One dysfunction was related to the presence of a PWM lesion and consisted of a limited repertoire of response variation. The other dysfunction was not related to the presence of a PWM lesion, but to preterm birth itself. It consisted of a change in the ability to modulate the postural responses. Preterm children showed a higher sensitivity to platform velocity than full-term children, and they lacked the capacity to modulate EMG amplitude with respect to initial sitting position.

Magnetic resonance imaging of periventricular leukomalacia and its clinical correlation in children

The prevalence of periventricular leukomalacia and its association with clinical neurological signs in school-age preterm children are unknown. We matched 42 eight-year-old children who were born before term with birth weights lower than 1,750 gm (mean, 1,410 gm; gestational age, 31 weeks) with 42 children who were born at term and of normal birth weight, to compare clinical neurological status and magnetic resonance imaging findings. Of the children born prematurely, 9.5% had cerebral palsy and 31% had minor neurological dysfunction whereas 9% of the children born at term had minor neurological dysfunction and none had cerebral palsy. Deviations in tongue movements, heel walking. Fogs test results, and finger opposition, as well as behavioral disturbances, differentiated the preterm from the full-teem group. The prevalence of periventricular leukomalacia among all children born prematurely was 32%. It was observed in all children with cerebral palsy, in 25% with minor neurological dysfunction, and in 25% of the clinically healthy preterm children. None of the children born at term had evidence of periventricular leukomalacia. Children with periventricular leukomalacia especially demonstrated poor performance on heel walking and Fogs test. Though commonly found in preterm children, periventricular leukomalacia is not uniformly associated with abnormal neurological findings. A thorough neurological examination is a better predictor of later developmental problems than is magnetic resonance imaging.

Minor neurological signs and perceptual-motor difficulties in prematurely born children

AIM

To examine the spectrum of neurological dysfunction and perceptual-motor difficulties at school age in a cohort of prematurely born children, and the relation of these measures to neonatal brain lesions, intelligence quotient, and behavioural adjustment.

METHOD

One hundred and eighty three children were tested at the age of 6 years using Touwen's Examination of the Child with Minor Neurological Dysfunction, the Movement Assessment Battery for Children (Movement ABC), the Developmental Test of Visual-Motor Integration (VMI), British Ability Scales, and Rutter Scales.

RESULTS

Twenty six children had definite cerebral palsy and one was blind. Of the remaining 156, the proportions falling below the 15th centile point were 31% on Touwen's Examination, 44% on the Movement ABC, and 17% on the VMI. Forty two passed all three tests. No child with a normal ultrasound scan developed cerebral palsy, whereas nearly all those with major lesions did. Minor lesions, however, were not generally predictive of later outcome. Correlations between the tests were generally low.

CONCLUSIONS

These findings stress the need to assess neurological and perceptual motor functioning separately at school age and to monitor relationships with other aspects of development.

Intrauterine growth and gestational age in preterm infants with cerebral palsy

In a case-control study, gestational age and intrauterine growth of 191 preterm singleton infants 1971-82 with cerebral palsy were compared to all preterm live-born singletons in Denmark in 1982 (N = 2203). The distribution of gestational age among preterm cases was slightly bimodal with maximum values at 29 and 32 weeks. The risk for cerebral palsy was highest in the infants with gestational age 28-30 weeks (OR = 5.6 (4.0-7.8), 95% confidence interval). Birth weight deviation, in the 34-36 weeks infants, expressed as the number of standard deviations from the mean birth weight for gestational age, was more negative in cases than in controls (P < 0.001). The frequency of small for gestational age (SGA) was 13% in cases and 9% in controls (OR = 1.5 (0.96-2.3), 95% confidence interval). The odds for cerebral palsy being SGA, was lower in 28-30 weeks (OR = 0.22 (0.06-0.86), 95% confidence interval), the same in 31-33 weeks (OR = 0.83 (0.35-2.0), 95% confidence interval) and higher in 34-36 weeks (OR = 5.2 (2.9-9.5), 95% confidence interval). In conclusion, preterm infants with cerebral palsy are born earlier than other preterm infants. Small for gestational age is associated with cerebral palsy in preterm infants only above 33 weeks.

[Handicaps in the perinatal period. I. Perinatal pathology and difficulties in school]

BACKGROUND

Major handicaps are closely related to perinatal events. However, relationship of these events with other moderate disabilities such as school problems are still unclear.

POPULATION AND METHODS

A representative sample of 1,408 children at school age and born in Lorraine in 1984 was studied. Two hundred and fifty children with problems were compared with 602 controls without school problems, using a multivariate analysis.

RESULTS

The incidence of school difficulties among 6-year old children (in the last year of nursery school) is 17.8%. Children are at higher risk of school problems if their parents are not (odds ratio [OR] = 7.9) or are poor school graduate (OR = 2.7), if they are boys (OR = 2.0), if they are born at the end of the year (OR = 1.1) and also if they are preterm (OR = 2.7) or small for gestational age (OR = 2.5). Preterm delivery and intra-uterine growth retardation accounted for 9.6% of school difficulties.

CONCLUSION

The relationship between perinatal events and school difficulties warrants to continue with prevention during pregnancy, especially among groups with multiple risk factors.

Some aspects of the reliability of Touwen's examination of the child with minor neurological dysfunction

Three studies concerning the inter-rater and test-retest reliability of the Touwen examination are presented. The results of the first study showed that it was not possible to achieve acceptable levels of reliability using the manual as the only reference for instruction. Although the reliability estimates of the total scores were good, inter-rater reliability for the nine groups of items and the individual tasks within them was poor. When methodology and interpretation of performance was agreed between observers, a second study showed that these disagreements diminished. The third study demonstrated that the short-term stability of total scores is good, but reliability for group and individual item scores remained poor.

Advances in neonatology. View from a practicing pediatrician

After reviewing the many problems that may be seen by the physician in follow-up care of the preterm infant and family, it is important to take a step back and evaluate the infant as a whole. In the vast majority of instances, the preterm infant will turn out to be normal. In an unfortunate minority, there may be difficult problems that the baby, parents, and caretakers must face. The pediatrician must remain diligent to attend to those problems that are correctable and to assist patients to their full potential.

Early fine motor and adaptive development in high-risk appropriate for gestational age preterm and healthy term children

The development of fine motor and adaptive skills during the first 2 years of life is reported in 97 high-risk preterm children and 94 healthy term children. Most stages of fine motor and adaptive development were found to occur at slightly later ages among preterm children. Neurological development was significantly correlated with fine motor and adaptive development in preterm children only. No significant influence of prenatal, perinatal and postnatal variables on fine motor and adaptive development was noted. No significant sex differences were observed in both the term and preterm group. The strongest predictors of later intellectual functioning were fine motor performance at 9 months and fine motor and adaptive skills at 18 to 24 months.

Intellectual outcome, speech and school performance in high risk preterm children with birth weight appropriate for gestational age

Intellectual development, speech and school performance of preterm infants with birth weight appropriate for gestational age are reported in two separate investigations: a longitudinal study of 97 preterm children and 93 term children as a control group, and a cross-sectional study of 249 preterm children. Both preterm groups were regarded as high risk groups with respect to number of outborns, distribution of gestational age and perinatal risk factors. Intellectual outcome at 5 and 7 years of age in the majority of the preterm children was comparable to that of the term children. However, 8% of the preterm boys and 2% of the preterm girls achieved lower IQ scores than any of the term children. Between 15% and 17% of the preterm boys and 9%-12% of the preterm girls did not attend school at grade level, compared to 4% and 2% in the term group, respectively. Intellectual and neurological development and school performance were higher interrelated in the preterm than in the term children. Articulation defects, stuttering and dysgrammatism occurred more frequently in the preterm than in the term children and in boys more so than in girls.