Origins and Predictors of Friendships in 6- to 8-Year-Old Children Born at Neonatal Risk.

OBJECTIVE: To test effects of gestational age (GA), early social experiences, and child characteristics on children's friendships and perceived peer acceptance. STUDY DESIGN: As part of the prospective Bavarian Longitudinal Study (1147 children, 25-41 weeks GA), children's friendships (eg, number of friends, frequency of meeting friends) and perceived peer acceptance were assessed before school entry (6 years of age) and in second grade (8 years of age) using child and parent reports. The parent-infant relationship was evaluated during the 5 months after birth. Child characteristics (ie, height, motor impairment, cognitive ability, behavioral problems) were measured at 6 years of age. Multiple regressions estimated effects of GA, parent-infant relationship, and child characteristics. RESULTS: Overall, children with higher GA had more friends, spent more time with friends, and were more accepted by peers at 6 years of age. Better parent-infant relationships, higher cognitive abilities, and fewer motor and behavioral problems predicted more friendships and higher peer acceptance after adjusting for sex, socioeconomic status, multiples, siblings, and special schooling. Across all GA groups, number of friends (child report: mean change, 1.77; 95% CI, 1.57-1.96) and peer acceptance (child report: mean change, 0.14; 95% CI, 0.09-0.19; parent report: mean change, 0.14; 95% CI, 0.11-0.17) increased with age, but the increase in number of friends was higher among preterm children (ie, interaction effect age*GA group: P = .034). CONCLUSIONS: Our results provide evidence of a dose-response effect of low GA on children's friendships and perceived peer acceptance. Improvements in early parenting and motor, cognitive, and behavioral development may facilitate friendships and peer acceptance for all children across the gestation spectrum.

Preterm Toddlers' Inhibitory Control Abilities Predict Attention Regulation and Academic Achievement at Age 8 Years.

OBJECTIVE: To determine if adverse effects of preterm birth on attention and academic abilities at age 8 years are mediated by children's inhibitory control abilities. STUDY DESIGN: Five hundred fifty-eight children born at 26-41 weeks gestation were studied as part of a prospective geographically defined longitudinal investigation in Germany. Toddlers' inhibitory control abilities were observed at age 20 months. At 8 years, attention and academic abilities were assessed. RESULTS: Preterm birth negatively affected children's inhibitory control abilities (B = .25, 95% CI [.11, .39], P < .001) and directly predicted subsequent low attention regulation (B = .23, 95% CI [.07, .38], P < .001) and academic achievement (B = .10, 95% CI [.03, .17], P < .001), after adjusting for other factors. Higher ability to inhibit unwanted behaviors predicted better later attention regulation (B = .24, 95% CI [.07, .41], P < .001) and academic achievement (B = .10, 95% CI [.03, .17], P < .001). CONCLUSIONS: The lower a child's gestational age, the lower the inhibitory control and the more likely that the child had poor attention regulation and low academic achievement. Adverse effects of preterm birth on attention and academic outcomes are partially mediated by toddlers' inhibitory control abilities. These findings provide new information about the mechanisms linking preterm birth with long-term attention difficulties and academic underachievement.

Universal gestational age effects on cognitive and basic mathematic processing: 2 cohorts in 2 countries.

OBJECTIVE: To determine whether general cognitive ability, basic mathematic processing, and mathematic attainment are universally affected by gestation at birth, as well as whether mathematic attainment is more strongly associated with cohort-specific factors such as schooling than basic cognitive and mathematical abilities. STUDY DESIGN: The Bavarian Longitudinal Study (BLS, 1289 children, 27-41 weeks gestational age [GA]) was used to estimate effects of GA on IQ, basic mathematic processing, and mathematic attainment. These estimations were used to predict IQ, mathematic processing, and mathematic attainment in the EPICure Study (171 children <26 weeks GA). RESULTS: For children born <34 weeks GA, each lower week decreased IQ and mathematic attainment scores by 2.34 (95% CI: -2.99, -1.70) and 2.76 (95% CI: -3.40, -2.11) points, respectively. There were no differences among children born 34-41 weeks GA. Similarly, for children born <36 weeks GA, mathematic processing scores decreased by 1.77 (95% CI: -2.20, -1.34) points with each lower GA week. The prediction function generated using BLS data accurately predicted the effect of GA on IQ and mathematic processing among EPICure children. However, these children had better attainment than predicted by BLS. CONCLUSIONS: Prematurity has adverse effects on basic mathematic processing following birth at all gestations <36 weeks and on IQ and mathematic attainment <34 weeks GA. The ability to predict IQ and mathematic processing scores from one cohort to another among children cared for in different eras and countries suggests that universal neurodevelopmental factors may explain the effects of gestation at birth. In contrast, mathematic attainment may be improved by schooling.

Preterm birth and dyscalculia.

OBJECTIVE: To evaluate whether the risk for dyscalculia in preterm children increases the lower the gestational age (GA) and whether small-for-gestational age birth is associated with dyscalculia. STUDY DESIGN: A total of 922 children ranging from 23 to 41 weeks' GA were studied as part of a prospective geographically defined longitudinal investigation of neonatal at-risk children in South Germany. At 8 years of age, children's cognitive and mathematic abilities were measured with the Kaufman Assessment Battery for Children and with a standardized mathematics test. Dyscalculia diagnoses were evaluated with discrepancy-based residuals of a linear regression predicting children's math scores by IQ and with fixed cut-off scores. We investigated each GA group's ORs for general cognitive impairment, general mathematic impairment, and dyscalculia by using binary logistic regressions. RESULTS: The risk for general cognitive and mathematic impairment increased with lower GA. In contrast, preterm children were not at increased risk of dyscalculia after statistically adjusting for child sex, family socioeconomic status, and small-for-gestational age birth. CONCLUSION: The risk of general cognitive and mathematic impairments increases with lower GA but preterm children are not at increased risk of dyscalculia.