Triglyceride response to intravenous lipid emulsion in small vs non-small for gestational age newborns: a retrospective cohort

Background: Small for gestational age (SGA) infants may have reduced lipid tolerance during intravenous lipid emulsion (ILE) therapy. We compared triglyceride (TG) levels in SGA versus non-SGA neonates receiving ILE and explored associations with neonatal morbidities. Methods: This retrospective study included neonates who received ILE for at least 24 hours. TG levels were measured at approximately 24 hours of life and at 30-60 days. Statistical analyses compared TG levels, the incidence of hypertriglyceridemia (TG > 250 mg/dL), and the change in TG levels over time between the groups. Results: 165 neonates were included, 56 (33.9%) SGA and 109 (66.1%) non-SGA. The mean ± SD gestational age at birth and birth weight were 34.2 ± 3.0 vs. 29.8 ± 2.6 weeks (p < 0.001), and 1,446 ± 336 vs. 1,325 ± 350 grams, respectively (p = 0.02). TG levels at 24 hours were significantly higher in the SGA group (144 [98, 189] vs. 85 [62, 116] mg/dL, p < 0.001). Incidence of hypertriglyceridemia was higher in SGA infants (10.7% vs. 1.8%, p = 0.019). Despite shorter duration of exposure (3.0 [2.0, 4.5] vs. 4.5 [3.0, 7.0] days, p < 0.001), a subgroup of SGA infants with follow-up data had higher TG levels at 30-60 days of life compared to non-SGA infants (106 [84, 155] vs. 70 [56, 91] mg/dL, p = 0.005). In multivariable analysis, SGA status, intraventricular hemorrhage, use of cardiotropic agents, and ClinOleic (vs. SMOFlipid) were independently associated with higher TG at 24 hours. Conclusion: SGA infants showed higher early TG levels and greater risk of hypertriglyceridemia during ILE, with elevations persisting at 30-60 days in the subgroup of SGA infants with follow-up data available. These findings support early TG monitoring and individualized lipid titration for SGA infants. Interpretation should consider the retrospective single-center design, baseline differences between SGA and non-SGA infants, and limited SGA follow-up sampling.