Hispanic newborns may face increased risk of some neural tube defects such as spina bifida and anencephaly, and it may be down to nutrition -- of a lack of it -- in the traditional Hispanic diet, researchers suggest.

A larger proportion of Hispanic women have babies in any given year than any other ethnic population in the country but are prone to delivering their babies prematurely, a follow-up to a 2008 March of Dimes survey found.

"One of the things that caught our eye was, while Hispanics represent 17 percent of the population, 24 percent of premature babies are Hispanic," said Dr. Edward McCabe, March of Dimes chief medical officer.

Premature birth increases the risk of neural tube defects, the researchers with the nonprofit organization said. Such defects occur during a pregnancy's early weeks, even before a woman becomes aware she's expecting

They are caused when the neural tube of the embryo, which will develop into the spinal cord and brain, fails to completely close.

One possible factor in the Hispanic population affecting the incidence of such defects may be low levels of folic acid, a form of B vitamin supplement that has proven effective against neural tube problems, the researchers say.

Unlike enriched wheat and rice products, which in the United States have had folic acid and other B vitamins added to them since 1998, corn masa flour -- a foundation staple of Hispanic diets -- is not required to contain it.

"This is why the March of Dimes is striving to have masa cornmeal fortified with folate," said Dr. Diana Ramos, a professor of obstetrics and gynecology at the University of Southern California. "Corn masa flour is not part of the standard American diet, so, since 2012, we've been working on this, making progress slowly."

The survey found Hispanic women also less likely to pursue a multivitamin regimen than is followed by other ethnicities, which could exacerbate the problems, the researchers said.

The March of Dimes has created a Spanish-language website providing information on specific health and nutritional concerns for Hispanics.

In addition to advice on pregnancy, the site offers help and counsel about a number of health issues faced by Hispanics including obesity, type 2 diabetes and smoking.

But birth defects and the health of expectant Hispanic mother remains a prime concern, McCabe said.

"By 2050, it's projected that 30 percent of the [U.S.] population of women of childbearing age will be Hispanic," he said. "Clearly, it's a growing population."