higher apparent motor development in infancy with DHA supplementation, as tested by the motor aspect of the Brunet-Lezine (p<0.05) (Agostoni et al., 1995) or general movement assessment (p=0.032) (Bouwstra et al., 2003). However, neither study found any benefit for movement or psychomotor development when the infants were tested again at 18 months of age. Birch et al. (2000) found higher (by 7 points) Bayley MDI scores at 18 months of age in term infants who consumed a formula supplemented with DHA and AA, compared to those who consumed the control formula (p<0.05), whereas Lucas et al. (1999) found no benefit of DHA and AA on either the Bayley MDI or PDI of term infants at 18 months of age.
It has been hypothesized that preterm infants may benefit more than term infants from DHA supplementation. Fewtrell et al. (2002, 2004) found no effect of supplementation on Bayley MDI of preterm infants in two other larger longitudinal studies.
Among smaller studies in preterm infants, however, Clandinin et al. (2005) in a randomized controlled trial found significant increases in both the Bayley MDI and PDI in preterm infants given DHA- and AA-supplemented formula (p<0.05) whereas van Wezel-Meijler et al. (2002) did not; Carlson et al. found higher Bayley MDI but not PDI at 12 months in only one of two preterm trial (Carlson et al., 1994, 1997).
Global tests such as the Bayley Scales of Infant Development and the Brunet-Lezine administered in infancy may be less related to performance on cognitive tests in childhood than more specific tests of attention and problem-solving (Carlson and Neuringer, 1999; Jacobson, 1999). While there is limited evidence from global tests of infant development (e.g., higher Bayley MDI scores in properly powered trials) to conclude there may be cognitive benefits of DHA supplementation for either preterm or term infants, evidence in support of benefits associated with DHA supplementation from specific tests in infancy that are more strongly related to several developmental parameters is mixed. O’Connor et al. (2001) assessed, among other measures, developmental outcomes in infants who received DHA- and AA-supplemented formula compared to controls. No differences were found in the Bayley MDI at 12 months, although the motor development index scores were higher among the supplemented infants who weighed less than 1250 g at birth compared to the nonsupplemented controls (p=0.007). When Spanish-speaking and twin infants were excluded from the analyses scores for the MacArthur Communicative Development Inventories, the supplemented infants had higher vocabulary comprehension at 14 months (p=0.01 for the egg triglyceride/fish group; p=0.04 for the fish/fungal group).
While there is limited evidence from global tests of infant development (e.g., higher Bayley MDI scores in properly powered trials) to conclude there may be cognitive benefits of DHA supplementation for either preterm or term infants, there is collective evidence of benefits associated with