Peanut consumption while pregnant is associated with a higher likelihood that a woman's allergy-prone baby will test positive for peanut allergy, a new study suggests.

The study examined babies with likely milk or egg allergies, or significant eczema, and their mothers' peanut-eating habits during pregnancy. The babies were selected based on characteristics that might indicate an increased risk of someday developing a peanut allergy.

"We found that maternal ingestion of peanut during pregnancy (which we asked about prior to allergy testing for peanut) was related to finding strong positive allergy tests to peanut in the children," Dr. Scott Sicherer, professor of pediatrics at the Jaffe Food Allergy Institute at Mount Sinai School of Medicine in New York, wrote in an email.

"The more peanut they reported eating during pregnancy, the higher the risk of finding a positive or strongly positive test to peanut."

The findings were published Monday in the Journal of Allergy and Clinical Immunology.

The 503 babies at five U.S. sites were between three months and 15 months old when their mothers were questioned about their peanut consumption during pregnancy, and the babies were tested for the presence of antibodies in the blood that would suggest they're allergic to peanuts.

A total of 140 infants had strong sensitivity to peanut based on their blood tests.

"The idea of the study in part is to watch the children over time and follow what happens to them, to test results, etc., as we see if they develop a peanut allergy and 'outgrow' or persist having egg or milk allergies as well," Sicherer wrote in response to questions about the study.

Risk factors for a positive test included being boys, being non-white, and having higher positive tests to milk or egg, Sicherer wrote.

He noted that a positive test for peanut allergy is not the same as being confirmed as having a peanut allergy, because many children with a positive test might be able to eat peanut.

"We have to wait a few more years to get that extra information," wrote Sicherer, who is the author of "Understanding and Managing Your Child's Food Allergies."

The findings add to the body of knowledge on the topic, but there are no easy answers for pregnant women wondering what to do.

"I think it's interesting and it definitely gives us more information, but it probably does not give us many answers, at least not definitive ones," said Dr. Susan Waserman, professor of medicine in the division of clinical immunology and allergy at McMaster University in Hamilton.

Ten years ago, the American Academy of Pediatrics recommended that women with babies at increased risk of allergy due to family history avoid peanut products while pregnant or breastfeeding.

"As time went on, we began to see that in spite of that information, the prevalence was still rising, that avoidance did not seem to make much of a difference," Waserman said in an interview.

"And in the past couple of years, those sorts of recommendations have basically been held back. People say, 'Look, we really don't have the evidence to recommend avoidance as a means of prevention."'

For instance, she noted that a U.K. researcher compared Israeli and British children, and found that prevalence of peanut allergy was far lower in Israel -- yet Israeli children consume peanut from a very early age in the form of a peanut candy, and their mothers do not avoid peanut while pregnant.

"So we've had studies that sort of line up on both sides of the fence and we still don't have a definitive answer, and what this study tells us is that the jury is still out," she said.

Sicherer concurred, and said there's no certain answer.

"Studies have fallen on both sides of this and it is hard to know what is right or if there is any definitive influence. I have had mothers say they ate a lot of peanut and think they caused a peanut allergy and I have had other mothers say they avoided and wonder why their child has an allergy," he wrote.

Sicherer said mothers should not have a guilty feeling about their past diet decisions, and whatever they feel comfortable doing is reasonable in the context of their past experiences.

Waserman said larger studies are being conducted that may provide answers in the years to come, including the CHILD study supported primarily by AllerGen NCE Inc., and the Canadian Institutes of Health Research, which will follow 5,000 children from "pre-birth" to five years of age.