Postnatal docosahexaenoic acid deficiency is an inevitable consequence of current recommendations and practice in preterm infants.

BACKGROUND: Very preterm infants are particularly susceptible to nutrient deficiencies. Although a lot of attention has been focused on the early nutrient supply, they are at high risk of long-chain polyunsaturated fatty acid deficiency.
OBJECTIVES: To estimate docosahexaenoic acid (DHA) intake, the metabolizable (i.e. absorbed) DHA, the DHA available for accretion and to quantify the DHA deficit, if any, during the first month of life of preterm infants born ≤28 weeks of gestation.
METHODS: Monocentric study. Nutritional data for the first 28 days of life were collected in 40 preterm infants born with a gestational age ≤28 weeks.
RESULTS: The metabolizable DHA intake (i.e. parenteral DHA + absorbed DHA) during the 1st, 2nd, 3rd and 4th weeks of life increased significantly over time (p < 0.0001), but corresponded to 7, 21, 30 and 39% of the fetal DHA accretion rate, respectively. Assuming endogenous synthesis, all infants exhibited a severe DHA deficit which reached on average 661 ± 100 mg/kg, which represents at least half of the DHA that should have been accumulated. The DHA deficit was highly correlated with birth weight, demonstrating that the smaller the infant, the larger the DHA deficit.
CONCLUSIONS: The current nutritional management of preterm infants is likely to lead to an early and severe DHA deficit which may represent, at 1 month of age, about half of the fetal DHA accumulation.