These cells are involved in the development of the nervous system and other tissues.

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The team believe that not only do the growth factors play a key role in development of the central nervous system, but also that too much of them may disrupt the normal process by which a cell develops into the correct type and moves to the right area, and dies at the right time.

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The study results point to the possible role omega-3s play in the development and maintenance of the nervous system, says Lammi-Keefe, who recommends that pregnant women eat at least three servings of omega-3-rich fish every week.

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