Preterm growth assessment: the latest findings on age correction.

OBJECTIVE

To evaluate the effect of age correction up to 36 months of age for growth assessments of extremely preterm (<28 weeks) and very preterm (28 to <32 weeks) infants.

STUDY DESIGN

This longitudinal analysis used data from the Preterm Infant Multicenter Growth Study (2001-2014).

RESULTS

1,416 children were included (Median gestational age = 27 weeks). Chronological age-based weight, height, and head circumference z-scores were consistently lower than those based on corrected age for all ages (0, 4, 8, 21 and 36 months) by up to -5.2 (95% confidence interval -5.4, -5.1) z-scores for length at term. Using chronological age, higher proportions of children were misclassified as having suboptimal growth (up to 72.9% misdiagnosed as stunted and 89.8% misdiagnosed as underweight at term).

CONCLUSION

For extremely and very preterm children, age correction is required for all growth measures through 36 months of corrected age.