Women who are fans of low carb diets may want to put their diets on hold for pregnancy. A new study finds that women who restrict their carbohydrates get less than half the folic acid of other women. That could lead to a higher risk of having babies with neural tube birth defects such as spina bifida and other disabilities. Folic acid also known as vitamin B9 is an essential nutrient. The research emphasizes that getting plenty of dietary folic acid is vital in the development of a baby’s spine and skull.  Consulting their health care provider about any special diets is vitally important for pregnant women, the study suggests.

Women on carb-restrictive diets such as Atkins, Paleo or Keto face a risk of babies with these birth defects that’s 30 percent higher than women following other diets, according to the study by the University of North Carolina at Chapel Hill. This research is the first to look at the connection between low-carb eating and neural tube defects. Neural tube defects (NTDs) include anencephaly, which is the lethal absence of major portions of the brain and skull. Malformations of the spine and spinal cord are other examples of neural tube defects.

Science had already discovered that a mother’s diet before and during early pregnancy plays a significant role in her baby’s development. News on the higher risk to low-carb moms is concerning because of the popularity of low carbohydrate diets, said research assistant professor Dr. Tania Desrosiers.

The Food and Drug Administration started requiring in 1998 the addition of folic acid to enriched grain products based on the estimation that one-fifth of US women have blood folate concentrations below the level recommended to reduce risk of neural tube defects. But with half of all pregnancies being unplanned, folic acid intake becomes increasingly important for women who may become pregnant. Many pregnant women start taking folic acid only after they learn a neural tube defect may have already occurred.

The journal Birth Defects Research published the study that analyzed data from 11,285 pregnant women from Arkansas, California, Georgia, Iowa, Massachusetts, New York, North Carolina, Texas and Utah. The National Birth Defects Prevention Study took place between 1998 and 2011. Some 9,545 had live born infants without birth defects. But 1,740 of these women had infants, stillbirths or terminations with anencephaly or spina bifida.

The Department of Health recommends a daily supplement of 400 micrograms of folic acid while women are trying to conceive. Moms-to-be should continue taking this dose for the first 12 weeks of pregnancy. The baby’s spine develops during that time.

Read More: Low Carb Diets Linked to Birth Defects