Here's a good reason to eat more bread: Researchers found that avoiding carbs before pregnancy may increase the risk of birth defects.

By Tina Donvito
January 29, 2018
low-carb pregnant
Credit: asife/Shutterstock

Many women believe being on a low-carb diet like Atkins, Paleo, Keto, or gluten-free can improve their health, but they may unknowingly be putting their future children's health at risk. According to a recent study published in the journal Birth Defects Research, women with a low carbohydrate intake are 30 percent more likely to have babies with certain birth defects.

What's missing from low-carb diets?

In the study, researchers from the University of North Carolina at Chapel Hill looked at data from more than 11,000 mothers who delivered during a 13-year period. "We found that women with low carbohydrate intake before conception had a higher risk of having a baby with a neural tube defect compared to other women," lead researcher Tania Desrosiers, PhD, MPH, of UNC's Gillings School of Public Health tells "This is significant because it points to a potential opportunity to prevent some birth defects in the future."

The connection between low carbs and neural tube defects (NTDs), which include spina bifida and anencephaly (absence of portions of the brain), may be in folic acid. This important nutrient has long been known to prevent NTDs, which is why prenatal vitamins are loaded with it. In addition, "this is why the FDA requires that folic acid be added to 'enriched' grain products like bread, pasta, rice, and cereal," Dr. Desrosiers says. Since 2016, the FDA also allows folic acid to be added to corn masa flour, which is used to make corn tortillas and tortilla chips.

Women who get pregnant while on low-carb diets, however, might be missing out on products enriched with folic acid. "As a scientific community, we've wondered if low-carb diets could lead to meaningful reductions in folic acid intake that could in turn lead to an increase in the risk of having a baby with a neural tube defect," Dr. Desrosiers says. "This study is the first to investigate this question directly."

Further findings of the study showed that dietary intake of folic acid among women on low-carb diets was less than half of other women, and more than 20 percent of women had folic acid levels below what's recommended to reduce the risk of NTDs. But, more research is needed to confirm the study's results.

Should you avoid low-carb diets?

"Pregnant women or women trying to become pregnant should have a conversation with their health care provider about their diet and any special eating patterns they might practice, and continue taking a vitamin every day before and during pregnancy that contains at least 400 micrograms of folic acid," Dr. Desrosiers says. There are also whole foods rich in folate (the natural form of folic acid), such as dark green leafy vegetables, legumes like peas and beans, oranges, and avocado.

But because half of all pregnancies are unplanned, all women of reproductive age should consider their folate or folic acid intake level. "Neural tube defects appear very early in pregnancy, often before a woman knows she is pregnant," Dr. Desrosiers says. "This is why the CDC recommends that all women who are capable of becoming pregnant take a vitamin containing at least 400 mcg of folic acid every day, whether or not they're trying to get pregnant."