As you approach the end of your pregnancy--particularly once you get past the 37th week, making you officially "full term"--you're likely to eagerly anticipate going into labor. Both because late pregnancy is uncomfortable and because it's natural to want to meet the baby, many women use herbs and foods to try to induce labor. As of 2011, there's no evidence green tea does so, however.
The end of pregnancy is an increasingly uncomfortable time for most women. Your baby grows rapidly in late pregnancy, gaining a quarter pound or more each week. Since there are technically three weeks between the start of being "full term" and your due date, that means your baby could grow by approximately three-quarters of a pound in that time; this makes earlier delivery quite attractive to many women. There are many foods and herbs rumored to start labor, and women commonly seek these out toward the end of pregnancy.
Green Tea and Labor
While there are many herbs recommended by some midwives and practitioners of alternative medicine as labor-inducers, there's no scientific evidence to support any of them. Green tea isn't even among the traditional labor inducers, and its inclusion among the foods purported to start labor is probably a function of the fact that it contains caffeine. Talk to your doctor before consuming green tea or any other herbal concoction during pregnancy, however.
Preterm Versus Term Labor
According to Drs. Michael Roizen and Mehmet Oz in their book "You: Having A Baby," you should avoid too much caffeine during pregnancy. Early in pregnancy, it can lead to miscarriage. Later on, the doctors explain, some studies show that it increases your risk of preterm labor. This isn't the same thing as labor induction, however, and you can't count on green tea to help induce labor because it contains a substance that might cause you to go into labor prematurely.
If you're unsure as to whether green tea is safe during pregnancy or how much caffeine you can safely consume, talk to your doctor. It's also a good idea to talk to your doctor before eating any food or taking any substance rumored to start labor. The last weeks of pregnancy are an important time for your baby in terms of brain development, explains the "Wall Street Journal," and inducing labor early--even only a week or two early--hinders proper development.