Allergies are increasing worldwide affecting 30-40% of the population. Among this, Atopic Dermatitis (AD) is the earliest and the most common manifestation of allergic diseases (prevalence 20%). Recent studies have shown that allergies were associated with a disruption of the gut microbial 'balance' suggesting that the use of nutritional intervention very early in life may restore an optimal pattern of microflora aiming at improving the host's health. So far, most human intervention studies have mainly focused on improving postnatal infant colonization. Our study will test the hypothesis that a maternal antenatal prebiotics (GOS/inulin) supplementation may be superior to placebo for AD prevention in high-risk children.