Prenatal maternal docosahexaenoic acid intake and infant information processing at 4.5mo and 9mo: A longitudinal study.

Alison Rees,Alison Wearden,Sylvain Sirois,Juan J Loor

doi:10.1371/journal.pone.0210984

Abstract

Previous research suggesting an association between maternal prenatal docosahexaenoic acid (DHA) intake and infant cognition has yet to assess whether there is a critical trimester for the observed effects. We used a comprehensive Food Frequency Questionnaire to estimate DHA levels during both the second and third trimesters of pregnancy, in a sample of 125 pregnant women. Infants were assessed at 4.5 months and 9 months post-partum using specific tests of visual acuity, habituation, and visual attention. Based on maternal DHA levels during pregnancy, mothers were subdivided into high, medium, and low groups, and their infants compared for task performance using one-way ANOVAs with maternal DHA groups. On the 9 month visual acuity test, infants whose mothers were in the medium DHA group performed significantly better than those with mothers in the low or high DHA groups (p = 0.008). However, no significant finding was found for any of the other cognitive assessment measures. Despite a number of studies reporting a positive effect of higher DHA levels on cognitive development, this study fails to support those conclusions. We can, however, conclude that it appears to be DHA intake in the third trimester specifically, which is influencing the development of visual acuity towards the end of the first postnatal year.

Highlights

Long-chain Polyunsaturated Fatty Acids (LCPUFAs), especially those of the Omega-3 (n-3) family, play a vital role in neurological functioning, being highly concentrated in the myelin sheath and membranes of synaptic terminals of the brain and central nervous system, (CNS) [1,2] and play an important role in the development and control of neurotransmitter systems [3,4]
It may be that the levels of docosahexaenoic acid (DHA) among the women in our sample were not high/variable enough to elicit increased performance in the cognitive tests employed; that the cognitive tests themselves were not sensitive enough to pick up on any performance differences; that the age of infant testing sessions was not appropriate to detect what may, potentially, be transient effects on cognitive development; or, that variations in prenatal maternal DHA intake do not have any significant effect on the development of infant attention or habituation performance
We found that infants whose mothers were in the medium DHA intake group had the best performance in the visual acuity task at 9 months of age

Summary

Introduction

Long-chain Polyunsaturated Fatty Acids (LCPUFAs), especially those of the Omega-3 (n-3) family, play a vital role in neurological functioning, being highly concentrated in the myelin sheath and membranes of synaptic terminals of the brain and central nervous system, (CNS) [1,2] and play an important role in the development and control of neurotransmitter systems [3,4]. Omega-3 LCPUFAs are believed to be important during the prenatal and early postnatal developmental periods[5,6,7] with docosahexaenoic acid (DHA, n-3 family) appearing to be the key nutrient at this time. DHA is preferentially transferred across the placenta and selectively accreted in fetal brain and retinal tissue during pregnancy[8,9], with rapid accretion and uptake beginning at the start of the third trimester, continuing throughout this trimester, and into the first two years of postnatal life, albeit at a slightly reduced rate

Objectives

Methods

Results

Discussion

Conclusion