Green tea is something I always stopped drinking after ovulation.
They did a study that found green tea blocked the amount of folic acid that is absorbed by the body. Doctors will probably vary on this.
If you are going to continue drinking green tea during pregnancy, then it might be wise to not drink it at the same time you take your prenatal vitamin.
Of course there are plenty of women that continued to drink green tea while pregnant with no problems.
My acupuncturist also advised that since green tea helps strengthen the immune system, it's not good to drink it after ovulation while TTC. Your immune system is actually lowered in pregnancy to let let the baby grow. Linking green tea to your immune system to pregnancy may be a bit far fetched. But there you go, that's another reason why some women choose to limit how much they drink.
As far as caffeine...most green tea is pretty modest. It varies on the kind.
See, Rach is a perfect example of drinking green tea with no problems. Lyndia is perfect!
It's more of a concern during the first trimester when the neural tube is forming. I think it's much less of a concern during later pregnancy.
Many people have m/s so bad in the first trimester that they can't drink much of anything. Maybe that's the natural way for our bodies to stay away from anything potentially harmful.
I don't think that a cup a week is going to be killer, but there are tons of tastey decaf green teas and white teas. I am a huge tea drinker, and it has been hard for me to cut back. I've switched mostly to black tea though, b/c I prefer green tea w/ Splenda and I don't want to be drinking any artificial sweeteners. In my black tea (Stash makes an excellent decaf Earl Grey) I like cream and sugar.
Celestial Seasonings has a really good decaf white called "White Pearl" I think. So good.