Coffee And Tea Consumption During Pregnancy Leads To Smaller Babies, No Matter The Quantity

If you're an avid tea or coffee drinker, a recent study out of Dublin has some important news for you about caffeine intake during pregnancy. Scientists have found that women who drink less than even the 'safe' amount of caffeine during pregnancy are more likely to give birth to smaller babies.

The study's researchers believe that caffeine restricts blood flow to the placenta, which in turn, restricts the baby's growth. The generally agreed-upon 'safe' amount of caffeine intake during pregnancy is 200 mg per day or less - which works out to about two mugs of coffee or three cups of tea. Interestingly, researchers found that even women who drank less than the safe cutoff were still more at risk of having low-birth-weight or premature babies.

The study followed 941 mother-child pairs born in Ireland. The mothers-to-be were asked to complete a dietary questionnaire, and the results were analyzed by researchers. Caffeine intake was shown to come predominantly from coffee, tea, soft drinks and cocoa-containing foods and beverages. Tea led the way as being the mothers' main source of caffeine (48 per cent), followed by coffee at 38 per cent.

The study's results suggested that for every additional 100 mg of caffeine consumed daily during the first trimester, birth weight was reduced by 0.5 lbs. They also suggested that increased caffeine consumption decreased babies' length and head circumference and gestational age. Women who consumed the most caffeine were found to have babies that weighed around 0.37 lbs less than those who consumed the least.

Dr. Ling-Wei Chen, lead researcher, recommends reducing caffeine intake during pregnancy - and even before, especially if a woman is actively trying to conceive.

"Based on the consistent associations we observed, and because many pregnancies are unplanned, we would recommend women who are pregnant or seeking to become pregnant at least limit their intakes of caffeinated coffee and tea," he said.


While the World Health Organization recommends women consume less than 300 mg of caffeine per day, other health organizations such as the NHS and the  American College of Obstetricians and Gynecologists advise no more than 200 mg.

But some experts, like Dr. De-Kun Li, a scientist at the Kaiser Permanente Northern California division of research in Oakland, believes these amounts are fairly high.

"The message to women I would prefer would be 'the less the better'," Dr. Li said. "Try to reduce as much as you can, if you can totally quit that would be even better."

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