Symmetrical and asymmetrical growth restriction in preterm-born children

Area of Science:

• Neonatal development
• Pediatric growth studies
• Perinatal medicine

Background:

• Premature infants often experience growth restriction, impacting long-term development.
• Distinguishing between symmetric (SGR) and asymmetric (AGR) growth restriction is crucial for understanding varied outcomes.
• Previous research indicates potential differences in developmental trajectories based on growth restriction patterns.

Purpose of the Study:

• To compare the growth and developmental outcomes of preterm infants with symmetric (proportionate) and asymmetric (disproportionate) growth restriction.
• To assess the influence of SGR and AGR on growth from birth to 4 years of age.
• To determine the association between growth restriction types and developmental delay at 4 years.

Main Methods:

• A community-based cohort study included 810 preterm infants (86 SGR, 61 AGR, 663 NGR) born in 2002-2003.
• SGR defined by birth weight <16th percentile and HC z-score not exceeding birth weight z-score by >1 SD.
• AGR defined by HC z-score exceeding birth weight z-score by >1 SD (brain sparing proxy); developmental delay assessed using Ages and Stages Questionnaire at 4 years.

Main Results:

• Longitudinal weight and height gains were similar between SGR and AGR groups, and less than NGR infants.
• At 4 years, weight z-scores were -1.1 (SGR), -0.7 (AGR), vs. -0.3 (NGR); height z-scores were -0.8 (SGR), -0.5 (AGR), vs. -0.2 (NGR).
• SGR infants showed greater head circumference (HC) gain, but by 1 year, HC z-scores were -0.2 (SGR) vs. 0.2 (AGR) and 0.1 (NGR); developmental delay odds ratios were 2.5 (SGR) and 2.1 (AGR).

Conclusions:

• Weight and height catch-up were similar for AGR and SGR preterm infants, but lagged behind NGR infants.
• Symmetric growth-restricted infants achieved catch-up in head circumference.
• Developmental delay risk was elevated in both SGR and AGR preterm infants, irrespective of initial head circumference.