Date Published: March 13, 2019
Publisher: Public Library of Science
Author(s): Julia Jaekel, Nicole Baumann, Peter Bartmann, Dieter Wolke, Joseph Najbauer.
Very preterm (<32 weeks gestation; VP) and/or very low birth weight (<1500g; VLBW) children often have cognitive and mathematic difficulties. It is unknown whether VP/VLBW children’s frequent mathematic problems significantly add to the burden of negative life-course consequences over and above effects of more general cognitive deficits. Our aim was to determine whether negative consequences of VP/VLBW versus healthy term birth on adult wealth are mediated by mathematic abilities in childhood, or rather explained by more general cognitive abilities. 193 VP/VLBW and 217 healthy term comparison participants were studied prospectively from birth to adulthood as part of a geographically defined study in Bavaria (South Germany). Mathematic and general cognitive abilities were assessed at 8 years with standardized tests; wealth information was assessed at 26 years with a structured interview and summarized into a comprehensive index score. All scores were z-standardized. At 8 years, VP/VLBW (n = 193, 52.3% male) had lower mathematic and general cognitive abilities than healthy term comparison children (n = 217, 47.0% male). At 26 years, VP/VLBW had accumulated significantly lower overall wealth than term born comparison adults (-0.57 (1.08) versus -0.01 (1.00), mean difference 0.56 [0.36–0.77], p < .001). Structural equation modeling confirmed that VP/VLBW birth (β = -.13, p = .022) and childhood IQ (β = .24, p < .001) both directly predicted adult wealth, but math did not (β = .05, p = .413). Analyses were controlled for small-for-gestational-age (SGA) birth, child sex, and family socioeconomic status. This longitudinal study from birth to adulthood shows that VP/VLBW survivors’ general cognitive rather than specific mathematic problems explain their diminished life-course success. These findings are important in order to design effective interventions at school age that reduce the burden of prematurity for those individuals who were born at highest neonatal risk.
Very preterm (<32 weeks gestational age, VP) and very low birth weight (<1500 g, VLBW) children have a highly increased risk for academic underachievement, in particular in mathematics [1–4], which has partly been attributed to underlying deficits in attention and executive function [5–8]. It remains controversial whether these mathematic deficits are domain specific  or rather explained by global cognitive problems . Data were collected as part of the prospective Bavarian Longitudinal Study (BLS) , a geographically defined whole-population sample of VP/VLBW and term control individuals in Germany. Participating parents were approached within 48 hours of the infant’s hospital admission and were included in the study once they had given written consent for their child to participate. Initial ethical approval was obtained from the University of Munich Children’s Hospital Ethics committee and again in 2009 from the Ethical Board of the University Hospital Bonn, Germany (reference #159/09). All adult participants gave fully informed written consent. Table 1 shows that, by definition, VP/VLBW participants were born at lower gestational age and birth weight and more often small for gestational age (SGA) than healthy term born comparisons. There were no group differences with regard to sex, but VP/VLBW adult participants had been born into families of lower SES than term comparisons. At age 8 years, VP/VLBW children had lower mathematic and general cognitive abilities (see Table 1 for details). At age 26 years, VP/VLBW had accumulated significantly lower overall wealth than term born comparison adults. This prospective 26 year longitudinal study shows that VP/VLBW birth and childhood IQ both independently and directly predict adult wealth, but childhood math does not seem to add to the predictive effects of these two major influences. Previous findings have documented the specific importance of childhood math for adult wealth in moderately and late preterm individuals . In contrast, our results suggest that general cognitive rather than mathematic problems may put VP/VLBW children on a trajectory of economic underachievement and diminished life-course success. Thus, specific math problems may have less of an impact on later wealth considering VP/VLBW individuals’ multiple neurocognitive difficulties. This finding adds to emerging evidence of life-long wide-spread changes in VP/VLBW’s brain networks that are associated with cognitive deficits in adulthood [42–45], and supports previous findings of multiple cognitive rather than specific problems after VP/VLBW birth . Source: http://doi.org/10.1371/journal.pone.0212789