Mothers-to-be with too much of a sweet tooth might increase the risk of asthma and allergies in their children, British research suggests.
High levels of sugar consumption during pregnancy doubled the chance of a child developing allergic asthma, the study of almost 9000 mother-child pairs showed.
Allergy risk was increased by up to 73 per cent but no link was found between sugar exposure in the womb and rates of eczema or hay fever.
The team compared the 20 per cent of mothers who consumed the most sugar when pregnant with the same proportion who consumed the least.
"We cannot say on the basis of these observations that a high intake of sugar by mothers in pregnancy is definitely causing allergy and allergic asthma in their offspring," said lead researcher Professor Seif Shaheen, of Queen Mary University of London.
"However, given the extremely high consumption of sugar in the West, we will certainly be investigating this hypothesis further with some urgency.
"In the meantime, we would recommend that pregnant women follow current guidelines and avoid excessive sugar consumption."
The study, published in the European Respiratory Journal, drew on data from the Avon Longitudinal Study of Parents and Children.
The investigation has followed the progress of children whose mothers were pregnant in the early 1990s.
The sugar link with asthma might be explained by high intakes of fructose triggering an immune response leading to inflammation in developing lungs.
Fructose is a type of sugar found in fruit and corn syrup and is widely used in processed food.
Freely consumed sugar in early childhood had no effect on the results, researchers said.
Fetal sugar exposure was what was important.
