When you're pregnant there are foods you crave. But study authors say, whether you want it or not, cut out the caffeine -- from coffee, soft drinks and tea.
This new study found consuming more than 200 milligrams of caffeine per day -- about one and half cups of coffee -- doubles the risk of miscarriage. Even smaller amounts appear to increase the risk.
Dr. Tracy Flanagan is a Kaiser-Permanente OB-GYN who will now start advising her pregnant patients to give up caffeine.
"What's different about this study is that it shows that a fairly low level of caffeine may be associated with miscarriage. And that's important," said Dr. Flanagan.
Caffeine is a stimulant that may be difficult for the fetus to metabolize. It also constricts blood vessels and may reduce blood flow to the fetus.
Tammy Plotkin-Oren has no way of knowing if coffee contributed to her devastating miscarriage seven years ago, but she gave up her three-to-five-cup-per-day habit for her later pregnancies.
"I figured if I can take out all the unhealthy things in my life, then the chances that I am going to have a healthy pregnancy are going to be greater," said Plotkin-Oren.
Pregnant women often do everything they can to try to be healthy. They exercise; they give up alcohol and cigarettes. And this study makes it clear there is one more thing to add to that list.
As women in one prenatal yoga class said, it's only for nine months.
"I do miss it," said expectant mother Aimee Price. "I miss having a hot cup of something in morning, but it's worth it."
That 200 milligrams of caffeine is equal to about two cups of coffee, or five 12-ounce sodas. If you're a tea drinker, that's about six 8-ounce cups of black tea.