A pediatrician in Montreal is suggesting that pregnant and nursing mothers avoid peanuts so their children don't develop peanut allergies, but the preliminary findings are not conclusive enough to change the advice women are given, other medical experts say.

The study by pediatric allergist Dr. Anne Desroches of Sainte-Justine Hospital involved 403 toddlers, about half of whom were allergic to peanuts. Their mothers filled in detailed questionnaires about breastfeeding, their diet during pregnancy and breastfeeding, exposure to peanuts and family history.

"The principal risk factor that we observed was not breastfeeding," Desroches said. "The risk factor was consumption of peanuts by the mother during pregnancy and the breastfeeding period."

Consumption of any amount of peanuts during pregnancy and breastfeeding seemed to be a significant risk factor for the development of peanut allergy in infancy, the study suggested.

But the findings may be flawed by recall bias, said Dr. Perle Feldman, medical director of the breastfeeding clinic at Jewish General Hospital.

"If their child is peanut-allergic, women are very quick to remember that maybe it was the peanuts they ate during pregnancy and breastfeeding that could have caused this thing," Feldman said.

"And so they're more likely to remember eating peanuts than women who have no reason to remember eating peanuts."

For women with a strong family history of anaphylaxis or severe allergies, it might be prudent to avoid peanuts, Feldman said.

Peanut allergies can be life-threatening and account for 50 to 100 deaths in the United States every year. The Canadian Pediatric Society advises restricting giving nuts to children until they are three years old.

"Until the evidence is really, really clear, I don't think women should make themselves crazy," Feldman said.

Desroches presented the findings of the unpublished study at the American Academy of Allergy, Asthma & Immunology in February.

In Britain, researchers are recruiting 480 children for a seven-year study. The study, called Learning Early About Peanut Allergies or LEAP, will divide babies into two groups, with one receiving peanut snacks regularly during the first three years and the control group avoiding peanuts completely.

The trial aims to determine whether avoiding peanuts helps prevent allergies. Depending on the results, the findings could guide public health policies on the prevention of food allergies.