Abstract
Background: Concentrations of the long-chain polyunsaturated fatty acids, in particular, the ω-3 (n–3) fatty acid DHA and the ω-6 fatty acid arachidonic acid (AA), decrease in infant blood during the first days after very preterm birth.
Objectives: This study aimed to explore factors associated with blood DHA and AA concentrations of very preterm infants receiving standard care, in the days following birth.
Methods: We examined the fatty acid composition of whole blood samples collected on cards at 0–6 d after birth, from a cross-sectional study of 1174 infants born <29 weeks of gestation in Australia, New Zealand, and Singapore.
Results: Considerable variation was observed in the proportions of blood AA (1.4%–18.0%) and DHA (0.4%–5.7%) concentrations. Infant blood DHA status was not associated with gestational age at birth, but AA was lower by 0.11% for each week of gestation (95% CI: −0.07%, 0.15%). There was an inverse relationship between age of sampling after birth and DHA (0.07% lower per day; 95% CI: 0.04%, 0.09%) and AA (0.09% lower; 95% CI: 0.04%, 0.14%). A concomitant positive relationship was observed between days after birth and the fatty acids present in the intravenous lipid emulsion administered: ω-6 linoleic acid (range: 2.1%–35.1%) and ω-9 oleic acid (range: 12.2%–52.9%).
Conclusions: Preterm infants whose blood was sampled later after birth have lower DHA and AA status relative to those sampled earlier after birth; samples taken at later timepoints are concurrently higher in the fatty acids of linoleic acid and oleic acid, which are the major compositional components of intravenous lipid emulsions routinely administered to preterm infants. The results support calls to develop intravenous feeds closely matching the fatty acid composition of infant blood at birth.
The N3RO Trial is registered at the Australian New Zealand Clinical Trial Registry as ACTRN12612000503820 (https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12612000503820).