Associations between preterm birth, small-for-gestational age, and neonatal morbidity and cognitive function among school-age children in Nepal

BACKGROUND The long term consequences of low birth weight (LBW), preterm birth, small-for-gestational age (SGA, defined as birth weight for given gestational age less than the 10th percentile of the reference), and early newborn morbidity on functional outcomes are not well described in low income settings. METHODS In rural Nepal, we conducted neurocognitive assessment of children (n = 1927) at 7-9 y of age, for whom birth condition exposures were available. At follow-up they were tested on aspects of intellectual, executive, and motor function. RESULTS The prevalence of LBW (39.6%), preterm birth (21.2%), and SGA (55.4%) was high, whereas symptoms of birth asphyxia and sepsis were reported in 6.7% and 9.1% of children. In multivariable regression analyses, adjusted for confounders, LBW was strongly associated with scores on the Universal Nonverbal Intelligence Test (UNIT), tests of executive function, and the Movement Assessment Battery for Children (MABC). Preterm was not associated with any of the test scores. Conversely, SGA was significantly (all p < 0.005) associated with lower UNIT scores (-2.04 SE = 0.39); higher proportion failure on Stroop test (0.06, SE = 0.02); and lower scores on the backward digit span test (-0.16, SE = 0.04), MABC (0.98, SE = 0.25), and finger tapping test (-0.66, SE = 0.22) after adjusting for confounders. Head circumference at birth was strongly and significantly associated with all test scores. Neither birth asphyxia nor sepsis symptoms were significantly associated with scores on cognitive or motor tests. CONCLUSION In this rural South Asian setting, intrauterine growth restriction is high and, may have a negative impact on long term cognitive, executive and motor function.