Originally Posted by andaluza
For the decaf coffee, you may want to consider using only Swiss water process decaf, which is a natural procedure. The typical decaf process involves chemicals that some consider more dangerous than the caffeine itself. There are actually a lot of threads on MDC regarding tea and coffee in pregnancy, so you could do a search to get to some specific discussions.
Agreed. It certainly won't hurt you or baby if you've had (or will have) a couple of cups of chemically treated decaf, but I wouldn't encourage anyone to drink it very often. I worked at Starbucks years ago and I remember there being one blend of decaf that used the Swiss Water method, but I would talk to your barista.
In terms of teas, there are a number of herbal teas that could be problematic in the first trimester, but some can be just fine. Red Raspberry Leaf is not such a good idea early on, but it's encouraged in the third trimester because it improves uterine contractions when the time comes. Some people say it induces labour, but I haven't found any evidence of that yet. Regardless, if you're being extra cautious, I would avoid drinking it until a couple weeks before you want baby to come out. I also found it surprising to learn that chamomile and hibiscus teas are also discouraged during pregnancy.
I generally stick to Rooibos tea. It has very little tannin because it is technically not a tea plant (which means it won't interfere with iron absorption), it has lots of antioxidants, and it's darn tasty. It's also nice because you can put sugar and milk in it like you would black tea or coffee to make it a nice, creamy, warm beverage to replace coffee, and it naturally does not contain caffeine. Just make sure that you're buying pure rooibos tea though, since many people mix herbs to make teas and you might end up drinking something you shouldn't be. Just ask to see ingredients - usually it's a short list for teas. Personally, I buy loose leaf organic rooibos from David's Tea http://www.davidstea.com/our-teas/rooibos/organic-rooibos You can get little disposable, biodegradable individual-use bags for them there too.