Aims

1. To re-analyze how the mother's diet during pregnancy and blood levels of DHA influence the WISC-III data from the ALSPAC study, considering the four indexes [verbal comprehension (VC), perceptual reasoning (PR), freedom from distractivility (FD) and processing speed (PS)]. The influence of FADS1, FADS2 and COMT polymorphisms as exposure variables, as well as other confounder factors will be also taken into consideration.

2. To study the potential long-lasting associations between mother's dietary intake of fish during pregnancy and the evolution of cognitive development. To achieve that, we will try to predict the cognitive score from 18 months to 8 years of age by comparing the scores from the Denver indexes with the WISC-III ones. After that, we will study the role of mother's blood DHA levels in the above hypotethized relationship.

Hypothesis

1. Maternal dietary intake of fish during pregnancy is correlated with the freedom from distractivility factor (FD) in WISC-III. FD is a factor which includes the subtests relating to working memory. In fact, FD is called working memory (WM) in the WISC-IV.

2. Children who show a high score in the Denver Scales at 18 months have also a high score in the WISC-III at 8 years old.

3. These relationships will be modulated by the influence of FADS1, FADS2 and COMT polymorphisms.

Statistical Procedure

1. To conduct an exploratory factorial analysis with the WISC-III subtests to obtain the factors/ indexes. Previous factor structure of the WISC-III was obtained in 2,200 children within a wide range of age from 6 to 16 years old (Weschler, 2003). However, it will be interesting to obtain a factorial structure for 8-9 year olds from ALSPAC, because some neuropsychological domains such us Working Memory have a critical period between 7 and 9 years of age.

2. For the second objective, regression analysis will be conducted using the WISC-III factors/indexes as dependent variables and the Denver indexes as predictors.

3. Once the factors are obtained, each factor will be related to the nutritional and genetic information.

Exposure variables

Mother's and children dietary intakes of fish

Mother's and child's blood levels of LC-PUFA (DHA & AA)

Genetic polymorphisms: FADS1, FADS2, FADS3, COMT

Outcome variables

WISC-III scores

Denver Developmental Screening Test

Confunder variables (all confounders considered in the ALSPAC Lancet paper in 2007).

Maternal age, mother's education, mother's BMI, smoking, breast-feeding, cultural level, Apgar score,..

This work would be a reanalysis of the data already used by Colin Steer for the Nutrimenthe work but looking at the neuropschological variables in more depth - the data can be compiled by Colin Steer so minimal support would be required from ALSPAC.