Large variability in Performance IQ associated with postnatal morbidity, and reduced Verbal IQ among school‐aged children born preterm

Abstract

Aim: To assess cognitive ability in a population‐based group of prematurely born school‐aged children and to relate these findings to postnatal morbidity. Method: The study group consisted of a cohort of 51 children born preterm, 43 (26 boys, 17 girls) of whom were available for psychological evaluation At evaluation, their median age was 10 y (range 8–11 y). They were all born between 1988 and 1991, with gestational age less than 29 wk (median 27, range 24–28). Their median birthweight was 1060 g (range 450–1450). The Wechsler Intelligence Scale for Children (WISC‐III) was used, and the test results were compared with those of a standardized, age‐matched, normative group of children. Results: Thirteen children (30%) performed below average [intelligence quotient (IQ) >80] for Full Scale IQ (FSIQ). Thirty‐six children had a Verbal IQ (VIQ) below the mean value of 100 [84%, 95% confidence interval 73–95%], p > 0.0001. The Performance IQ (PIQ) was within the expected range of a normal population, although a large variability was observed. Discrepancies between VIQ and PIQ of more than 15 IQ units were found in 42% of the children. High postnatal morbidity (days with assisted ventilation, number of blood transfusions) and low birthweight standard deviation scores (SDS) were associated with lower PIQ than VIQ, while low postnatal morbidity and high birthweight were associated with higher PIQ than VIQ. Conclusion: This cohort of preterm children had reduced overall verbal capacity independent of morbidity, and a large variability in performance capacity that was associated with postnatal morbidity. The findings suggest that there are different mechanisms influencing the outcome of verbal and performance capacity in preterm children.

Oculomotor Control in Children Who Were Born Very Prematurely

“…51 The absence of notable saccade deficits in the preterm children in this study may be because the lesions that occur very early in life are compensated for by neural plasticity and development. In addition, severe lesions in preterm children are likely to be associated with cognitive deficits and reduced IQ, 52 which were excluded from the cohort that we examined and may also explain the absence of manifest strabismus found in the preterm group.…”

Follow‐up studies of very low birthweight children in Sweden

“…In the EPT‐H3 study, 43 of 56 children were tested on the WISC III, with a median age of 10 years (range, 8–11 years) (13). Thirteen children (30%) performed below average (IQ < 80) on the Full Scale IQ and 14% of the children had exceptionally low intelligence function (IQ < 70).…”

“…According to the EPT‐H2 study in which the Teacher’s Report Form (TRF) was utilized, 38% of EPT children and 12% of controls performed below grade level (10). A majority of the parents (58%) in the EPT‐H3 study described their children as having or having had reading problems, spelling problems or both, to various degrees (13). Fifty‐three per cent of the children received extra support from the class teacher or a special teacher.…”

“…In this review, only those studies with follow‐up ages of 3–20 years were included. The Swedish follow‐up studies concern seven populations: four populations are hospital based, two of which are mixed hospital and population based, including 20–210 children (9–14); one population is regional and comprises 86 children (15–20); and two populations are national and comprise 370 and 86 children, respectively (21–24). The latter population is a subpopulation of the national study of ELBW children, which concerns EPT children born at 23–25 weeks of gestation, thus representing children born just within the limits of viability.…”

Dificuldade de aprendizagem em escolares de muito baixo peso ao nascer

“…1 A significant part of this reduction is the result of reductions in neonatal mortality brought about by pharmacological and technical advances, both in delivery rooms and intensive care units. [2][3][4][5][6][7][8][9][10][11][12] Exogenous surfactant treatment has been particularly decisive to the survival of neonates with very low birth weights (below 1,500 g) and extremely low birth weights (below 1,000 g). 13 According to the literature on this subject, these babies are at increased risk of sequelae such as cerebral palsy, intellectual deterioration and convulsions, 14 in addition to blindness and deafness.…”