Pregnancy studies leave ACSH staffers skeptical

A new study shows that obese women who become pregnant after losing weight with the help of bariatric surgery have easier pregnancies and healthier babies than women who remain obese during pregnancy. But ACSH's Dr. Ruth Kava thinks the article left out a vital piece of information: "It doesn't distinguish between gastric banding and gastric bypass surgeries, and there's a big difference in what happens to nutrient absorption after these types of surgeries -- which probably affects pregnancies," she says.

She raises a similar question regarding a study claiming that maternal smoking during pregnancy might cause children to have thicker walls in the carotid arteries in the neck, raising their risk for heart disease later in life. "But the news report didn't mention whether they controlled for or tracked whether the offspring smoked themselves," she points out.

An even bigger problem plagues the study's finding that if mothers consume canola oil as opposed to corn oil during pregnancy and lactation, their offspring have a lower risk of breast cancer -- but so far the results only apply to mice. "There's nothing wrong with doing well-designed animal studies, but a problem arises when researchers try to directly extrapolate from them to humans," Dr. Kava says.

ACSH's Jeff Stier adds, "We are especially concerned because expectant mothers tend to have an understandably heightened sense of caution when it comes to their health. The problem is that when these studies find their way into the mainstream media, they exploit that fine line between caution and gullibility."