Association between small-for-gestational age and neurocognitive impairment at two years of corrected age among infants born at preterm gestational ages: a cohort study
To investigate the association between small-for-gestational age (SGA) and neurocognitive impairment at 2 years of corrected age among infants born at preterm gestational ages.STUDY DESIGN:
A secondary analysis of a prospectively conducted NICHD/Maternal-Fetal Medicine Units BEAM trial. Nonanomalous pregnancies delivered before 37 weeks of gestation were included in the analysis. Neurocognitive outcomes at 2 years of corrected age were compared between infants who were SGA (< 10% for gestational age) and those appropriately grown (AGA). The primary outcome was a severe or moderate neurocognitive impairment at 2 years of corrected age among survivors, defined as either mental (MDI) or psychomotor (PDI) developmental index score < 70 for severe and < 85 for moderate impairment.RESULTS:
Of 2299 preterm neonates 67 (3%) were SGA. SGA infants were more often twin pregnancies (31% vs 17%, P = 0.003) and delivered more often by cesarean section (63% vs 40%, P < 0.001) at similar gestational ages (30.0 ± 2.6 vs 29.5 ± 2.8 weeks, P = 0.11). At 2 years of corrected age, SGA and AGA survivors had similar rates of neurocognitive impairment (MDI < 70: 18% vs 18%, P = 1.0; MDI < 85: 44% vs 46%, P = 0.96; PDI < 70: 20% vs 15%, P = 0.51; PDI < 85: 40% vs 34%, P = 0.48).CONCLUSION:
In this cohort, SGA at preterm gestational ages was associated with similar rates of neurocognitive impairment at two years of corrected age among surviving infants.