(7) GRADuates of the NICU: Evaluation of a Nutrition and Growth Support Clinic for Preterm Infants

Background: Preterm infants frequently experience postnatal growth challenges, with many developing extrauterine growth restriction (EUGR), defined as a decline of ≥1 weight z-score from birth to discharge on the Fenton Growth Chart. EUGR is associated with long-term risks such as developmental delays, hypertension, diabetes, and dyslipidemia. Although neurodevelopmental follow-up clinics are widespread for Neonatal Intensive Care Unit (NICU) graduates, specialized post-discharge nutrition clinics are rare. The Great Results After Discharge (GRAD) Clinic was established at the University of Wisconsin in 2019. It aims to support providers by guiding fortification strategies and improving growth trajectories to reduce the incidence of EUGR.

Objectives: To characterize growth trajectories and rates of EUGR of preterm infants enrolled in a specialized post-NICU nutrition clinic.

Design/Methods: This retrospective cohort study included all infants born between June 2019 and December 2022 at UnityPoint Meriter Hospital’s Level III NICU who attended at least one GRAD clinic visit and had a primary care provider within the University of Wisconsin or UnityPoint systems. Infants with external PCPs were excluded. Data collected in REDCap includes infant demographics, medical history, nutrition, and anthropometrics through the first year of life. Infants were categorized into EUGR and non-EUGR groups based on whether they experienced a ≥ 1 decline in a weight z-score from birth to NICU discharge. Growth trends were analyzed using linear mixed-effect models with time as a fixed effect and infant as a random effect. Analyses were conducted in R (v4.40).

Results: Of 198 eligible infants, 75 met inclusion criteria with 51% females and 49% males. Gestational ages ranged from 23.4-39.7 weeks with a mean (SD) 31.9 (3.4). Birth weight ranged from 0.57 – 4.05 kilograms (kg) with a median of 1.57 kg (IQR 1.23, 1.98) out of which 12% were small for gestational age. Eighteen infants (24%) had EUGR at discharge while 57 (76%) did not. Growth trajectories showed a notable decline in weight z-scores in both groups between 3 and 6 months of age, with the average decrease of -1.03 (95% CI -1.24, -0.82).

Conclusions: EUGR remains prevalent, affecting 1 in 4 NICU graduates. Post-discharge growth faltering, particularly between 3 and 6 months of age, is evident among infants despite being followed in a specialized nutrition clinic. Future steps include comparing growth outcomes with infants not attending the GRAD clinic.