Just wanted pass along this research. Anecdotally, I think it's right, just based on my own experience. I think caffeine may contribute to premature labor, too. Now this conclusion is right, too:
“Moderation in all things is still an excellent rule,” Dr. Westhoff said. “I think we tend to go overboard on saying expose your body to zero anything when pregnant. The human race wouldn’t have succeeded if the early pregnancy was so vulnerable to a little bit of anything. We’re more robust than that.”The thing is, all women are different and have different sensitivities. Plus, people are so much more nutritionally deprived. A diet of empty calories might be tolerable normally, but a pregnant woman needs solid nutrition and to avoid stressors. She will face enough the way things go in our society, anyway.