Fetal intrauterine whole body linoleic, arachidonic and docosahexaenoic acid contents and accretion rates

Abstract 

Introduction

There is no information on the whole body fatty acid (FA) contents of preterm or term infants, although scattered information on the FA-composition of many organs is available.

Material and methods

We collected data on the weights, lipid contents and FA-compositions of the quantitatively most important fetal organs of appropriate for gestational age (AGA) Western infants. From these we estimated the total body contents of linoleic (LA), arachidonic (AA) and docosahexaenoic (DHA) acids at 25, 35 and 40 weeks of gestation.

Results

Western infants accrete FA in the order of LA>AA>DHA at all stages during pregnancy and the highest accretion rates are reached in the last 5 weeks of gestation, i.e. 342mg LA, 95mg AA and 42mg DHA/day. At term, most of the infant's LA, AA and DHA is located in adipose tissue (68, 44 and 50%, respectively), with substantial amounts of LA also located in skeletal muscle (17%) and skin (13%); of AA in skeletal muscle (40%) and brain (11%); and of DHA in brain (23%) and skeletal muscle (21%). The term AGA infant has accreted about 21g LA, 7.5g AA and 3g DHA, which constitutes a gap of 12g LA, 3.3g AA and 1.5g DHA compared to a 35 weeks old AGA infant.

Conclusion

The current fetal LA, AA and DHA pool sizes and accretion rates may especially be useful to estimate the preterm infant's requirements and the maternal LCP needs during pregnancy. Since they derive from populations with typically Western diets they do not necessarily reflect ‘optimality’ or ‘health’.

Keywords: Intrauterine, Fatty acids, Accretion rate, Linoleic acid, Arachidonic acid, Docosahexaenoic acid, LA, AA, DHA, Fetal, Adipose tissue, Preterm, Milk, Recommendation, Requirement, Term