D. Jill Shaddy

DHA supplementation and pregnancy outcomes

BACKGROUND Observational studies associate higher intakes of n-3 (omega-3) long-chain polyunsaturated fatty acids (LCPUFAs) during pregnancy with higher gestation duration and birth size. The results of randomized supplementation trials using various n-3 LCPUFA sources and amounts are mixed. OBJECTIVE We tested the hypothesis that 600 mg/d of the n-3 LCPUFA docosahexaenoic acid (DHA) can increase maternal and newborn DHA status, gestation duration, birth weight, and length. Safety was assessed. DESIGN This phase III, double-blind, randomized controlled trial was conducted between January 2006 and October 2011. Women (n = 350) consumed capsules (placebo, DHA) from <20 wk of gestation to birth. Blood (enrollment, birth, and cord) was analyzed for red blood cell (RBC) phospholipid DHA. The statistical analysis was intent-to-treat. RESULTS Most of the capsules were consumed (76% placebo; 78% DHA); the mean DHA intake for the treated group was 469 mg/d. In comparison with placebo, DHA supplementation resulted in higher maternal and cord RBC-phospholipid-DHA (2.6%; P < 0.001), longer gestation duration (2.9 d; P = 0.041), and greater birth weight (172 g; P = 0.004), length (0.7 cm; P = 0.022), and head circumference (0.5 cm; P = 0.012). In addition, the DHA group had fewer infants born at <34 wk of gestation (P = 0.025) and shorter hospital stays for infants born preterm (40.8 compared with 8.9 d; P = 0.026) than did the placebo group. No safety concerns were identified. CONCLUSIONS A supplement of 600 mg DHA/d in the last half of gestation resulted in overall greater gestation duration and infant size. A reduction in early preterm and very-low birth weight could be important clinical and public health outcomes of DHA supplementation. This trial was registered at clinicaltrials.gov as NCT00266825.

Visual Scanning and Pupillary Responses in Young Children with Autism Spectrum Disorder

Using eye-tracking technology we investigated visual scanning and pupillary responses to face and non-face stimuli in nine children (M = 49.6 months) with Autism Spectrum Disorder (ASD) compared to six mental-age and nine chronological-age matched children. The results revealed a significant decrease in visual scanning to landscapes. In addition, the ASD group showed pupillary constriction to childrens faces, while control groups showed pupillary dilation. Visual scanning responses to landscapes had a negative correlation with the Behavior subscale of the Autism Diagnostic Observation Schedule-Generic for the ASD group. Potential use of these measures as early indicators of ASD is discussed.

Long-term effects of LCPUFA supplementation on childhood cognitive outcomes

BACKGROUND The effect of long-chain polyunsaturated fatty acid (LCPUFA) intake on cognitive development is controversial. Most randomized trials have assessed cognition at 18 mo, although significant development of cognitive abilities (early executive function) emerge later. OBJECTIVE The objective was to evaluate cognition beyond 18 mo and longitudinal cognitive change from 18 mo to 6 y in children who were fed variable amounts of docosahexaenoic acid (0.32%, 0.64%, and 0.96% of total fatty acids) and arachidonic acid (ARA; 0.64%) compared with children who were not fed LCPUFA as infants. DESIGN Eighty-one children (19 placebo, 62 LCPUFA) who participated in a double-blind, randomized trial of LCPUFA supplementation as infants were re-enrolled at 18 mo and tested every 6 mo until 6 y on age-appropriate standardized and specific cognitive tests. RESULTS LCPUFA supplementation did not influence performance on standardized tests of language and performance at 18 mo; however, significant positive effects were observed from 3 to 5 y on rule-learning and inhibition tasks, the Peabody Picture Vocabulary Test at 5 y, and the Weschler Primary Preschool Scales of Intelligence at 6 y. Effects of LCPUFAs were not found on tasks of spatial memory, simple inhibition, or advanced problem solving. CONCLUSIONS The data from this relatively small trial suggest that, although the effects of LCPUFAs may not always be evident on standardized developmental tasks at 18 mo, significant effects may emerge later on more specific or fine-grained tasks. The results imply that studies of nutrition and cognitive development should be powered to continue through early childhood. This parent trial was registered at clinicaltrials.gov as NCT00266825.

Heart rate-defined phases of attention, look duration, and infant performance in the paired-comparison paradigm.

Four-month-old infants (N = 68) were tested in a paired-comparison familiarization-novelty recognition task in which the length of choice trials was systematically manipulated. Peak look duration during pretest and familiarization periods significantly predicted a dichotomous measure of recognition performance, but recognition was unaffected by choice-trial length. Heart rate (HR) was simultaneously assessed during the task, and the amount of time infants spent in various HR-defined phases of attention was assessed. Longer durations of looking during pretest and familiarization were significantly associated with more time spent in both sustained attention (SA) and attention termination (AT). Of these two variables, only individual differences in AT accounted for significant variance in recognition memory performance. A final analysis addressed the possibility that individual differences in AT mediated the relation between look duration and recognition performance. These findings provide support for the hypothesis that individual differences in the disengagement of attention underlie the relation between look duration and cognitive performance in early to midinfancy.

A Longitudinal Investigation of the Development of Attention and Distractibility

We longitudinally investigated the development of endogenous control of attention in 2 types of tasks that involve competition for attentional focus at 7, 9, and 31 months of age. At all 3 sessions, children participated in a multiple object free play task and a distractibility task. The results revealed both developmental differences and continuity of attentional skills. There was clear evidence of stability in distractibility between 9 and 31 months, and infant distractibility measures were related to toddler attention in the multiple object free play task. The results are discussed in terms of the development of endogenous control of attention and the underlying processes that may guide stability in attentional control.

Prenatal DHA Supplementation and Infant Attention

Background:Results of randomized trials on the effects of prenatal docosahexaenoic acid (DHA) on infant cognition are mixed, but most trials have used global standardized outcomes, which may not be sensitive to effects of DHA on specific cognitive domains.Methods:Women were randomized to 600 mg/d DHA or a placebo for the last two trimesters of pregnancy. Infants of these mothers were then followed on tests of visual habituation at 4, 6, and 9 mo of age.Results:DHA supplementation did not affect look duration or habituation parameters but infants of supplemented mothers maintained high levels of sustained attention (SA) across the first year; SA declined for the placebo group. The supplemented group also showed significantly reduced attrition on habituation tasks, especially at 6 and 9 mo.Conclusion:The findings support with the suggestion that prenatal DHA may positively affect infants’ attention and regulation of state.