When is it most important to take omega 3 while pregnant?

I am 6months pregnant and read I should take a seperate Omega 3 supplememnt(without fish oil to avoid mercury) for babys brain developement and eyes.I wasnt told by my doctor is it too late in my pregnancy to make a difference?|||It's never too late for both you and the baby! If you take fish oil for omega-3 supplementation be sure and consume "pharmaceutical grade". Omega-3 pharmaceutical grade fish oil is much more concentrated so you obtain much more benefits from a given dosage and toxins such as PCB's, dioxin, mercury and oxidized lipids have been removed. Typical health food grade fish oils are not pharmaceutical grade. The only way to be sure is to ask to see third party laboratory anaylsis of the finished product. It should contain at least 60% long chain omega-3 fatty acids (EPA + DHA), less than 45 ppb PCB's and less than 1 ppt dioxin.