Adult Functional Outcome of Those Born Small for Gestational Age: Twenty-six–Year Follow-up of the 1970 British Birth Cohort

Abstract

CONTEXT: Although studies have documented cognitive impairment in children who were born small for gestational age (SGA), other studies have not demonstrated differences in IQ or other cognitive scores. The need exists for long-term studies of such children to assess functional outcomes not measurable with standardized testing. OBJECTIVE: To determine the long-term functional outcome of SGA infants. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: A total of 14,189 full-term infants born in the United Kingdom on April 5 through 11, 1970, were studied as part of the 1970 British Birth Cohort; 1064 were SGA (birth weight less than the fifth percentile for age at term). Follow-up at 5, 10, 16, and 26 years was 93%, 80%, 72%, and 53%, respectively. MAIN OUTCOME MEASURES: School performance and achievement, assessed at 5, 10, and 16 years; and years of education, occupational status, income, marital status, life satisfaction, disability, and height, assessed at 26 years, comparing persons born SGA with those who were not. RESULTS: At 5, 10, and 16 years of age, those born SGA demonstrated small but significant deficits in academic achievement. In addition, teachers were less likely to rate those born SGA in the top 15th percentile of the class at 16 years (13% vs 20%; P<.01) and more likely to recommend special education (4.9% vs 2.3%; P<.01) compared with those born at normal birth weight (NBW). At age 26 years, adults who were SGA did not demonstrate any differences in years of education, employment, hours of work per week, marital status, or satisfaction with life. However, adults who were SGA were less likely to have professional or managerial jobs (8.7% vs 16.4%; P<.01) and reported significantly lower levels of weekly income (mean [SD], 185 [91] vs 206 [102] pound sterling; P<.01) than adults who were NBW. Adults who were SGA also reported significant height deficits compared with those who were NBW (mean [SD] z score, -0.55 [0.98] vs 0.08 [1.02]; P<.001). Similar results were also obtained after adjusting for social class, sex, region of birth, and the presence of fetal or neonatal distress. CONCLUSIONS: In this cohort, adults who were born SGA had significant differences in academic achievement and professional attainment compared with adults who were NBW. However, there were no long-term social or emotional consequences of being SGA: these adults were as likely to be employed, married, and satisfied with life.