Overconsumption of Diet Soda May Elevate Risk of Premature Birth

Women who are pregnant and consume caffeine, even as little as one cup of coffee a day, are at a higher risk of delivering an underweight baby. Diet sodas, which contain both caffeine and artificial sweeteners, may not only contribute to underweight births, but also to premature births in those women who drink large amounts.

In January 2008, researchers from the U.S. found that pregnant women that consumed two or more cups of coffee daily are at twice the risk of having a miscarriage as those women who avoid caffeine during their pregnancy. In the study, women who were pregnant that consumed one to two cups of coffee per day, or between 100-199 milligrams, had a 20 percent increased risk of having a baby with a low birth weight.

In a recent study out of Statens Serum Institut in Copenhagen, researchers studied 60,000 Danish women who reported on their diet, including how many soft drinks they had each day, at around 25 weeks of pregnancy. Approximately 3,000, about 5 percent, delivered premature babies (defined as those prior to 37 weeks gestation). They found that women who had at least one serving of artificially sweetened soda a day while they were pregnant were 38 percent more likely to deliver preterm than women who drank no diet soda at all, while women who had at least four diet sodas a day were nearly 80 percent more likely to deliver preterm.

The exact reason for the increase is preterm birth amongst diet soda enthusiasts was unknown. While some speculate the aforementioned caffeine, not all diet beverages contain caffeine. So it could be artificial sweeteners or even a combination of the two. Indirect evidence has linked aspartame to preterm delivery in animals, which yields a clue, but more research is necessary to pinpoint the cause