476 - Cohort Study on Growth and Neurodevelopmental Outcomes up to 2 Years of Age in Symmetric and Asymmetric Small-for-Gestational-Age Preterm Infants

Publication Number: 4467.476

Shushu Li, Nanjing Women and Children's Healthcare Hospital, Nan jing, Jiangsu, China (People's Republic); Jin yanyu, Nanjing Women and Children's Healthcare Hospital, Nanjing, Jiangsu, China (People's Republic); Shuping Han, Nanjing Women and Children's Healthcare Hospita, Nanjing, Jiangsu, China (People's Republic)

Background: With advances in neonatal intensive care, the survival of preterm small-for-gestational-age (SGA) infants has improved. SGA remains a significant cause of perinatal morbidity and mortality, associated with long-term growth and neurodevelopmental delays. Assessing SGA solely by birth weight is insufficient; incorporating body proportions offers a more comprehensive approach. Evidence suggests symmetric (sSGA) and asymmetric (aSGA) subtypes carry distinct risks, yet comparative cohort studies are scarce.

Objective: This study aimed to systematically compare perinatal characteristics, physical growth from birth to 2 years, and neurodevelopmental outcomes between sSGA and aSGA preterm infants (birth weight ≤1500g). It further sought to explore the mediating role of growth parameters and identify unique risk patterns to guide earlier intervention.

Design/Methods: In this retrospective cohort study, infants were classified according to the Fenton 2013 growth standards. Physical growth (height, weight, head circumference) was assessed at 0, 6, 12, and 18 months. Neurodevelopment was evaluated using the Gesell Developmental Scale at 6, 12, and 24 months. Mediation analysis was conducted using the PROCESS plugin in SPSS.

Results: The study included 217 infants (sSGA: 68; aSGA: 149). Perinatally, sSGA had lower birth weight/head circumference/body length Z-scores, larger gestational age, and a higher incidence of severe fetal growth restriction (all P< 0.05). During hospitalization, sSGA showed smaller weight loss and faster recovery (P < 0.05). Growth patterns differed: sSGA's weight caught up to aSGA by 12 months corrected age (P=0.087), while head circumference delay persisted until 24 months actual age (P=0.061). At 24 months, sSGA scored significantly lower in adaptability, fine motor, language, and personal-social domains (all P< 0.05), but not in gross motor skills (P=0.494). Mediation analysis confirmed that birth head circumference Z-score directly predicted language and personal-social DQ (effect sizes: 6.38, 6.16), with head circumference at 40 weeks and 1 month corrected age serving as significant mediators(indirect effects: 1.43 and 1.71).

Conclusion(s): Head circumference trajectory is a key indicator distinguishing sSGA and aSGA and is critically associated with neurodevelopmental outcomes at 2 years. Despite rapid weight and length catch-up, sSGA exhibits significant head circumference delay, linked to poorer multi-domain development. Focused follow-up and early intervention targeting head circumference, particularly from discharge to 1 month corrected age, may improve long-term outcomes.

Figure 1. Physical Growth Trajectories from 40 Weeks of Corrected Age to 24 Months of Actual Age.
Figure 1. Physical Growth Trajectories from 40 Weeks of Corrected Age to 24 Months of Actual Age.
Weight, Length, and Head circumference growth (presented as Z-scores) are shown for symmetric (sSGA, red line) and asymmetric (aSGA, blue line) small-for-gestational-age infants. While sSGA infants showed rapid catch-up in weight and length, their head circumference growth was significantly delayed.

Figure 2. Neurodevelopmental Outcomes at 24 Months of Actual Age in Preterm Infants with Asymmetric (aSGA) and Symmetric (SGA) Growth Restriction
Figure 2. Neurodevelopmental Outcomes at 24 Months of Actual Age in Preterm Infants with Asymmetric (aSGA) and Symmetric (SGA) Growth Restriction
Developmental outcomes across five domains of the Gesell Developmental Scale are shown. At 24 months of actual age, infants in the symmetric SGA (sSGA) group showed significantly lower developmental quotients (DQ) in the adaptability, fine motor, language, and personal-social domains compared to the asymmetric SGA (aSGA) group (all P < 0.05). No significant between-group difference was observed in the gross motor domain (P = 0.494). Data are presented as mean DQ scores ± standard deviation. * P < 0.05.

Figure 3. Path Analysis of the Mediating Effect of Head Circumference on Neurodevelopment
Figure 3. Path Analysis of the Mediating Effect of Head Circumference on Neurodevelopment
This model illustrates the mediating role of head circumference growth in the relationship between birth head circumference Z-score and neurodevelopmental outcomes at 24 months. Birth head circumference Z-score directly and positively predicted both language and personal-social developmental quotients (DQs), with effect sizes of 6.38 and 6.16, accounting for 81.69% and 78.27% of the total effects, respectively. Head circumference Z-scores at 40 weeks of corrected gestational age and at 1 month of corrected age served as significant mediators, with indirect effects of 1.43 and 1.71, accounting for 18.31% and 21.73% of the total effects, respectively. Solid lines represent significant direct effects, while dashed lines indicate significant indirect effects through the mediators.