Caffeine and Pregnancy

Published: 2/10/2008

A recent study of miscarriage rates in the early stages of pregnancy, points a finger at caffeine. Those pregnant women in the study who took in more than 200 milligrams of caffeine per day had a 25% miscarriage rate, as opposed to a 12.5% risk of losing a pregnancy in those who took in no caffeine. While the study had its limitations, this is an extremely significant difference in statistical terms.

The researchers suspect the danger comes from the dramatic metabolic effects the drug caffeine has on both the newborn and the placenta (the organ that allows oxygen and other nutrients to be delivered from mom to baby). As a stimulant and a constrictor of blood vessels, caffeine might prevent the free flow of nutrients to the fetus and/or the flow of toxins and waste products away from the fetus. While the mechanisms of miscarriage are speculative, the end result is clear and without much scientific doubt.

How much caffeine is 200 milligrams a day? Caffeine levels vary by brand, portion size, and food type, but on average, you’ll get 200 milligrams of caffeine in just one or two cups of coffee or three cups a day of tea. And it’s not just in drinks. Caffeine can also be found in soft drinks, energy drinks, ice cream, chocolate, candies, and other foods, as well as in some over-the-counter pain relievers and sleep aids. For a list of caffeine sources, go to the Center for Science in the Public Interest website at www.cspinet.org/new/cafchart.htm 

What’s the take-home? As I’ve said before, what you eat and drink during pregnancy definitely impacts the health of your baby. Moderation is the key to a successful pregnancy. Expectant mothers should be aware of this study and make the appropriate dietary adjustments. Until more research solidifies these findings, I advise women with high-risk pregnancies or those with have a history of miscarriages to avoid caffeine entirely. Those at low-risk should keep their caffeine intake under 200 mg. a day.

American Journal of Obstetrics and Gynecology, January 24, 2008