They based their findings, published in the latest issue of the journal Archives of Disease in Childhood (Fetal and Neonatal edition), on 98 pregnant women, who were given either 4g of fish oil supplements or 4g of olive oil supplements daily from 20 weeks of pregnancy until the birth of their babies.
Their children's growth and development, including language, behaviour, practical reasoning and hand-eye co-ordination, were assessed at two- and-a-half years of age.
In all, 72 children were assessed - 33 in the fish oil group and 39 in the olive oil group. Those whose mothers had taken the omega-3-rich fish oil supplements scored significantly higher than those whose mothers had taken olive oil. They also scored more highly in measurements of comprehension, average phrase length and use of vocabulary.