Omega-3 and omega-6 polyunsaturated fatty acids in neurodevelopment and prematurity: Correcting imbalances and closing the Preterm PUFA Gap

Preterm birth has a worldwide prevalence of around 11 %, and > 95 % of preterm infants now survive into adulthood. However, improved survival is accompanied by increased risks of later life chronic disorders. The brain is enriched in arachidonic acid (ARA) and docosahexaenoic acid (DHA), which are essential for optimum brain and visual system development, and cardiovascular and immune system function. Fetal demand for ARA and DHA is high, especially in the last trimester. Prior to birth they are provided by placental transfer, enriched by placental biomagnification, which occurs in parallel with placental bioreduction of linoleic acid (LA). However, after birth preterm infant feeding results in marked decreases in tissue levels of ARA and DHA, and concomitant increases in LA. This phenomenon we term the Preterm PUFA Gap, which may be a key factor in adverse health consequences of preterm birth. The review begins with a summary of the evidence highlighting the importance of DHA in reducing the risk of early preterm birth. We then develop the concept of the Preterm PUFA Gap, including discussion of the conflicting results of intervention trials with ARA and DHA. This is followed by a review of potential approaches to close the Preterm PUFA Gap.