I actually researched this one a lot... studies are pretty clear that it really positively impacts baby's brain development, and I take it now and will continue to take it throughout pregnancy (if I ever get there).
My living proof- the little guy I nanny for is 23 months old and his mom took DHA every day of her pregnancy... right now he can sing at least 15 songs by heart, is speaking in 3-4 word sentences, can count to ten,
and recognizes and can name all 26 letters of the alphabet, even out of order. Extremely impressive, in my (biased

) opinion...