The research into children's behavior and intelligence suggests that instead of protecting the unborn baby, women who cut fish out of their diet altogether may miss out on vital nutrients that the developing brain needs -- and so unwittingly harm their children.

Seafood is the predominant dietary source of long-chain omega-3 fatty acids, which are essential for development of the nervous system.

The findings come from a study of almost 9,000 British families taking part in the Children Of The 90s project at the University of Bristol.

This research result contradicts U.S. research which suggests pregnant women should limit their intake of seafood to avoid exposing a fetus to trace levels of neurotoxins such as mercury, which can inhibit brain development in young children.

In 2004 the U.S. Environmental Protection Agency and FDA jointly advised pregnant and nursing women against eating more than 340 grams of seafood a day because of concerns about levels of toxic mercury in fish.

The lead researcher, Joseph Hibbeln of the U.S. National Institutes of Health, and the Bristol scientists, including Professor Jean Golding, compared the amount of fish eaten by pregnant mothers with the development of their children up to the age of eight and concluded that "women had low levels of seafood consumption, the outcome is exactly the opposite of what was assumed by the United States advisory."