Though not as much as coffee, tea also contains caffeine and as such raises concerns about safety during pregnancy.
The rule of thumb for drinking tea during pregnancy is that you should be having it in moderation – as of now there is no evidence that tea could cause any problems of pregnancy or complications of negative effects for the baby, so there is no reason to discontinue drinking tea.
If however you drink a lot of tea each day, it is advisable to cut down to no more than a couple of cups a day.
Rather than tea, it may be other items that contain even more caffeine that a pregnant woman should be aware of – caffeinated drinks, coffee ice cream, and certain medications, so it is important to watch out for those as well.
With herbal teas however one does need to exercise greater caution. Herbal teas may consist of much different kind of herbs, some of which are safe to take otherwise, but may be cause for problems during pregnancy.
While some herbs are relaxing and promote good health even during pregnancy others are known to start premature labor and even be a factor in inducing a miscarriage.