green tea a no go?

I read somewhere (I just wish I could remember where) that you shouldnt drink green tea while pregnant. Something about the antioxidants preventing absorbtion of folic acid and leading to neural tube defects.... extreme I know. I want to say I read it in your pregnancy week by week while I was browsing at the book store. I've done some online searches and haven't found anything that says anything remotely like this. Any thoughts or knowledge on this. I know the point is to keep caffeine intake take, but green tea has very small amounts of caffeine.