Craig J. Sander

Neonatal hypoxic risk in preterm birth infants: the influence of sex and severity of respiratory distress on cognitive recovery.

The authors examined the differential effects of neonatal respiratory distress syndrome (RDS)--a condition associated with elevated risk for neonatal hypoxia-ischemia--on the cognitive development of the two sexes. The authors also attempted to establish whether the severity of respiratory distress is linked to cognitive outcome. Findings revealed an appreciable female advantage in cognitive recovery from RDS, yet the association between severity of RDS and outcome did not reach conventional statistical significance level. The sex effect on intelligence test performance was significantly greater for nonverbal subtests than for verbal ones. These results augment earlier findings of sex differences in cognitive recovery from perinatal intracranial hemorrhage. The current investigation also extends these results to a population of children at neonatal hypoxic risk for whom early brain injury was excluded on the basis of neonatal cranial ultrasound findings.

Influence of slight to moderate risk for birth hypoxia on acquisition of cognitive and language function in the preterm infant: a cross-sectional comparison with preterm-birth controls.

The cognitive and language performance of a group of 26 preterm-birth preschool and early school-age children with slight to moderate risk for perinatal hypoxia was compared with the performance of a preterm-birth comparison group of 26 children. Despite the relatively small discrepancy in degree of risk, the cognitive performance of the 2 groups diverged significantly. When data for children with known perinatal arterial pH were combined, a curvilinear (quadratic) regression model provided the best fit. Increasing acidosis was linearly related to decreases in cognitive skills, with the bend in the curve occurring well within the normal range of pH values. Hence, in the preterm infant, even minor risk for birth hypoxia may result in discernible deviation from the expected developmental trajectory.

Neurodevelopmental outcome in children born to mothers with hypertension in pregnancy: the significance of suboptimal intrauterine growth.

In this investigation of 45 children born to mothers with hypertension in pregnancy, our objective was to examine the role of a fetal risk factor (suboptimal intrauterine growth [SOIUG]) in determining developmental outcome. There were two groups of children: Group 1 (n=26; 10 males, 16 females; mean testing age 56.77 mo [SD 13.03], range 41–82 mo; mean gestational age 32.96 wks [SD 2.24], range 27–38 wks; mean birthweight 1984.42g [SD 563], range 1046–3515g) without, and Group 2 (n=19; 6 males, 13 females; mean testing age 57.63 mo [SD 14.86], range 40–84 mo; mean gestational age 34.21 wks [SD 2.10], range 29–39 wks, mean birthweight 1572g [SD 365], range 855–2690g) with SOIUG. We found that SOIUG was associated with a significant reduction in cognitive and motor skills (p<0.05). Visuospatial (p<0.01) as well as motor skills (p<0.001) were linearly associated with the extent of intrauterine growth deficit when the latter was treated as a continuous variable. To conclude, an increase in intrauterine growth deficit is accompanied by a proportionate decline in quality of developmental outcome in children born to mothers with hypertension in pregnancy.

The effects of perinatal hypoxic risk on developmental outcome in early and middle childhood: A twin study

The goal of this study of 66 twins was to determine whether motor and cognitive functions assessed in early and middle childhood are vulnerable to perinatal hypoxic risk. In an earlier study of 76 infant and toddler twins (S. Raz, F. Shah, & C. Sander, 1996), the authors found that intrapair discrepancy on the Mental Developmental Index, but not on the Psychomotor Developmental Index, of the Bayley Scales of Infant Development was associated with discordance for perinatal hypoxic risk. The twins at lower risk outperformed their higher risk co-twins. In the present study the authors sought to establish in a new sample of preschool and school-age twins whether gaps in performance persist into early and middle childhood. Although the disparity in hypoxic risk between the co-twins was typically moderate, significant intrapair differences were observed on the measure of motor performance. Among the motor abilities examined, skills involving visually guided ballistic arm movements appeared to be the most vulnerable to perinatal risk.

Densidade dos movimentos oculares rápidos durante o sono ativo em recém-nascidos pré-termo

Rapid eye movement (REM) density has been helpful as a reliable index of phasic eye movements activity during REM (active) sleep in adults. We evaluated this index in 28 newborns, at 34 to 39 weeks of conceptional age (CA). The 5 hours Polysomnographie recording during sleep included electroencephalogram, electrooculogram, electrocardiogram, pneumogram, nasal thermistor for detecting airflow, and continuous oxygen saturation (tcP02) monitoring. REM density was measured by two distinct criteria: a - REM density as the duration of phasic eye movements in relation to REM periods (REMP). Such index varied from 10.6 to 14.1% and was higher in the 36-37 weeks CA group. b - REM density was calculated as a percentage of 10-second epochs of REM sleep in which phasic eye movements occurred. This criterion confirmed the narrow range of such index in this age bracket (39.9-44.6%), was higher in the first REMP and in the 36-37 weeks CA group. Our data suggest that REM density is a consistent phasic REM sleep feature in preterm newborns with levels close to the adult population, inspite of the gradual decrease of REM sleep duration with age. Higher indices were also found in the first REMP and in the 36-37 weeks CA grou by both methods.Rapid eye movement (REM) density has been helpful as a reliable index of phasic eye movements activity during REM (active) sleep in adults. We evaluated this index in 28 newborns, at 34 to 39 weeks of conceptional age (CA). The 5 hours polysomnographic recording during sleep included electroencephalogram, electrooculogram, electrocardiogram, pneumogram, nasal thermistor for detecting airflow, and continuous oxygen saturation (tcPO2) monitoring. REM density was measured by two distinct criteria: REM density as the duration of phasic eye movements in relation to REM periods (REMP). Such index varied from 10.6 to 14.1% and was higher in the 36-37 weeks CA group. REM density was calculated as a percentage of 10-second epochs of REM sleep in which phasic eye movements occurred. This criterion confirmed the narrow range of such index in this age bracket (39.9-44.6%), was higher in the first REMP and in the 36-37 weeks CA group. Our data suggest that REM density is a consistent phasic REM sleep feature in preterm newborns with levels close to the adult population, in spite of the gradual decrease of REM sleep duration with age. Higher indices were also found in the first REMP and in the 36-37 weeks CA group by both methods.