It doesn't matter, if it's coffee, tea, soda, or even hot chocolate. A new study provides the strongest proof that caffeine can increase the risk of miscarriage, even in relatively small amounts.

When Tammy Plotkin-Oren got pregnant with her daughters she cut out coffee – cold turkey.

The mother of three, and former caffeine-lover made the decision after her first pregnancy ended in a miscarriage.

"I decided anything under my control that I could do to prevent something from going wrong, I was going to do," Plotkin-Oren said.

Today researchers are offering some of their strongest evidence that caffeine and pregnancy don't mix.

"This study clearly shows 200 mg or more is associated with an increased risk of miscarriage," said Dr. David Walton, Regional Perinatology Chair, Kaiser Permanente.

The study, involving more than 1,000 pregnant women, shows those who drink two or more cups of coffee a day are twice as likely to miscarry as those who avoid caffeine all together. The risk isn't just coffee, but caffeine itself. So, five or more 12 ounce cans of caffeinated soda -- and an equivalent amount of caffeine in tea and hot chocolate -- can pose the same danger. With so many non-preventable causes of miscarriage, researchers want women to focus on how they can optimize their pregnancies going forward.

"The first choice they should probably consider is to stop drinking caffeine, entirely, if they can," said study author Dr. De-Kun Li.

The next best option: limiting caffeine consumption to under two cups of coffee a day. For Plotkin-Oren it was a no-brainer to go from three cups to zero.

"The minute I knew it was going to be affecting a baby, it seemed to be, it just wasn't as difficult," she said.

Like every mom she gets tired. Doctors say brisk walks and healthy snacks are good pick-me-up alternatives.