By Devin Saucier

Expecting mothers beware: Drinking caffeinated beverages may increase the risk of having a low birth weight baby, new research indicates.

For years, doctors have warned pregnant women to limit their caffeine intake, but in a study of more than 59,000 healthy women, researchers at the University of Gothenburg in Sweden found that even conservative intake may be problematic.

The women, whose pregnancies were uncomplicated through delivery, reported their daily caffeine intake at gestation weeks 17, 22, and 30. Coffee, tea, soda, energy drinks, and chocolate consumption were all recorded.

The results showed women who drank more daily caffeine were more likely to deliver a baby small for gestational age (SGA).

One study author, Dr. Verena Sengpiel, told WND that in the short term, SGAs “might have trouble in keeping their body temperature and their blood glucose levels.”

She also noted that “other studies have found SGA infants have lower neurodevelopment scores.”

Individuals born SGA may remain small even as adults.

While SGA babies are typically at elevated risk for both neonatal morbidity and mortality, the study authors pointed out that “this might not be true for babies born SGA due to maternal caffeine consumption,” adding that further research is needed “to establish the impact of caffeine on neonatal morbidity and mortality.”

Dr. Sengpiel and her colleagues did not study the way caffeine might cause small birth weight, but one theory they cited is that the adrenaline spike caused by caffeine may decrease blood flow to the placenta and thereby restrict fetal growth.

The study, published in the journal BMC Medicine, also examined the association of caffeine intake with gestation period. Researchers found that coffee, but not other caffeine sources, slightly increased gestation length – by about five to eight hours for each cup of coffee consumed daily.

They noted, “It is not caffeine, however, that is the cause of this association,” but either some other ingredient in coffee or some behavior associated with coffee drinking.

The authors did not find this troublesome.

“A prolongation of gestational length by some hours probably lacks clinical significance,” Dr. Sengpiel told WND. “However, we did not study the risk for post term delivery . . . which is known to increase the risks for both maternal and fetal health.”

Currently, the World Health Organization recommends pregnant women drink less than 300 milligrams of caffeine – about three cups of coffee—per day. In 2010, the American College of Obstetricians and Gynecologists recommended a 200 mg per day caffeine limit, an amount the new research still associated with increased SGA risk.

So what are pregnant women to do? Dr. Sengpiel stressed to WND that while her research did not find that caffeine causes increased SGA risk, she and her team did find a “robust association” between the two. Since she doesn’t think the randomized control trial necessary to prove a causal link will be done, “women should be informed of findings like ours so that they can choose to pause their caffeine consumption while pregnant.”

At the least, Dr. Sengpiel recommends expecting mothers “follow the official recommendations of less than two cups coffee per day.”

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