Is Omega 3 essential for brain development when pregnant?

I cannot eat seafood. I am allergic to a lot of it but I am pregnant and want to make sure I am getting the nutrients I need for my baby. I have heard Omega 3 helps brain development in your baby while pregnant. Is fish the only way to get it? Should I take an Omega 3 supplement? I am takinf a prenatal vitamin but I am not sure if it contains any Omega 3 fatty acids.|||It is essential after 6 months of pregnancy. That is the time the baby will start it's major brain developmnent. Also, I reccomend you ask your Dr to prescribe you pregvite. It has to b prescirbed by your doctor. It has all the vitamins and nutrients you need in it. It can be hard on your stomach though, especially in the morning. (It is much better than all the over the counter pregnancy pills).