335 - Timing of Complementary Food Introduction and Growth Outcomes at 8- and 20-Months Corrected Age in Former Very Preterm Infants

Publication Number: 3323.335

Emily R. Sullivan, Rush Medical College of Rush University Medical Center, Cortlandt Manor, NY, United States; Olivia Zoog, Rush Medical College of Rush University Medical Center, Chicago, IL, United States; Sooliat Bakare, Rush Medical College of Rush University Medical Center, Chicago, IL, United States; zeynep Isgor, Rush Medical College of Rush University Medical Center, Chicago, IL, United States; Kousiki Patra, Rush Medical College of Rush University Medical Center, Chicago, IL, United States; Tricia J.. Johnson, Rush University, Chicago, IL, United States; Aloka L. Patel, Rush Medical College of Rush University Medical Center, Chicago, IL, United States

Background: Current infant feeding recommendations vary, with some advising exclusive mother's own milk for 6 months before introducing complementary foods (solid foods), while others recommend solids beginning at 4-6 months. Limited data suggest earlier timing of solid food introduction (TSFI) in former very preterm (VPT, gestational age (GA) < 32 weeks) infants may support growth, but evidence is sparse.

Objective: To evaluate whether growth outcomes at 8- and 20-months corrected age (CA) in former VPT infants differ by TSFI.

Design/Methods: Infants born < 32 weeks GA during Nov 2020-Oct 2024 were enrolled into a prospective neonatal intensive care unit (NICU) follow-up study. Mothers completed diet questionnaires every 2 weeks from NICU discharge through 4 months CA and monthly from 5-20 months CA. Infants were categorized by TSFI: < 6 months CA vs. ≥6 months CA. Weight, length, and head circumference (HC) were measured at 8- and 20-month CA visits and converted to z-scores, adjusted for sex and CA. Subjects were included in this analysis if they had complete TSFI data and anthropometric data at either 8- or 20-month CA. Independent sample t-test was used to assess whether weight, length, and HC standardized measurements (z-scores) differed across the two TSFI groups.

Results: Of the 73 former VPT infants, 28 (38%) had TSFI < 6 months CA. At 20 months CA, infants with TSFI < 6-month CA had significantly higher weight z-scores (0.347) and length z-scores (0.515) compared with TSFI ≥6 months CA (weight: -0.621; length: -0.126). HC z-scores did not differ significantly between groups. At 8-month CA, no significant differences between TSFI groups in z-scores were noted.

Conclusion(s): Mean standardized weight and length measures at 20-month CA differed significantly by TSFI in former VPT infants. These findings constitute limited evidence on modest growth benefits of earlier complementary feeding and warrant further evaluation of the relationship of TSFI with long-term growth and adiposity. These future studies would benefit from incorporating larger samples and analytical strategies that aim to address potential sources of confounding.

Table 1. Description of Sample
Data are presented as mean (standard deviation), or median (interquartile range) for continuous variables and n (%) for categorical variables. P-values represent comparisons between infants <6 months and ≥6 months corrected age (CA), calculated using independent t-tests, Mann-Whitney U test, or chi-square tests, as appropriate.

Table 2. Comparison of Weight, Height and Head Circumference z-scores at 8- and 20-Month CA
Mean z-scores of growth parameters at 8- and 20-month corrected age (CA) are reported. P values are obtained from independent t-tests of comparing means between the two TSFI groups ( <6 months and ≥ 6 months) at each time point. Significance is indicated with yellow highlights. (n) is the sample size, the number of participants with available growth measurements at the corresponding visit.

Figure 1. Comparison of changes in anthropometric z-scores between 20- and 8-months based on timing of solid food introduction
Change in growth z-scores between 8 and 20 months corrected age among infants with both timepoints available, stratified by timing of solid food introduction (TSFI). For infants introduced to solids 6 months before corrected age ( <6mo CA) length n = 21, weight n = 20, and head circumference n = 14. For those introduced to solids after 6 months corrected age (≥ 6mo CA) length n = 23, weight n = 20, and head circumference n = 18.