Neurodevelopmental outcomes among extremely premature infants with linear growth restriction

Abstract

Objective: To compare neurodevelopmental outcomes in linear growth-restricted (LGR) infants born <29 weeks with and without weight gain out of proportion to linear growth.

Study design: We compared 2-year neurodevelopmental outcomes between infants with and without LGR and between LGR infants with and without weight gain out of proportion to linear growth. The outcomes were Bayley-III cognitive, motor, and language scores, cerebral palsy, Gross Motor Function Classification System (GMFCS) level ≥ 2, and neurodevelopmental impairment.

Result: In total, 1227 infants were analyzed. LGR infants were smaller and less mature at birth, had higher BMI, and had lower Bayley-III language scores (82.3 vs. 85.0, p < 0.05). Among infants with LGR, infants with high BMI had lower language scores compared with those with low-to-normal BMI (80.8 vs. 83.3, p < 0.05), and were more likely to have GMFCS level ≥2 and neurodevelopmental impairment.

Conclusion: Among infants with LGR, weight gain out of proportion to linear growth was associated with poorer neurodevelopmental outcomes.

Figure 1

Graphical depiction of length percentiles at birth and status for infants with (light gray bars, dotted line) and without (dark gray bars, solid line) LGR (A), and of BMI percentiles at birth and status for LGR infants with elevated (light gray bars, dotted line) versus low-normal (dark gray bars, solid line) BMI (B). The bars are constructed as histograms and the curves represent smoothed density curves. The third shade of gray noted is where the histogram bars overlap for each of the two groups. Note the leftward shift in length percentiles from birth to status in infants with LGR (A), and the separation of BMI curves from birth to status in LGR infants (B) suggesting different patterns of weight gain relative to linear growth.

Figure 2

Bar graph demonstrating the observed mean composite Bayley scores for infants without LGR (dark solid gray columns), with LGR (light solid gray columns), with LGR and elevated BMI (checkered gray columns) and with LGR and low-normal BMI (striped gray columns). The black bars represent the standard error. The # denotes a p-value < 0.05 between groups on unadjusted analysis. After multivariate analyses, only the observed differences in language scores between infants with and without LGR (*, Model 1, p<0.05) and LGR infants with high versus low-normal BMI (^, Model 2, p<0.05) remained significant.