Early pregnancy in spring may increase food allergy risk in child
MedWire News: Babies born in October and November are more likely to be born with food allergies than babies born at other times of the year, possibly due to their mother's exposure to pollen during the 11th week of gestation, say Finnish researchers.
"The fetus begins to produce immunoglobulin E antibodies at approximately the 11th gestational week," explain Kaisa Pyrhönen (University of Technology, Lappeenranta) and colleagues, who add that this process should stop at the end of the second trimester but in some cases, continues until birth.
The team conducted food-specific allergy testing on 961 of the 5,920 children born in South Karelia, Finland, between 2001 and 2006.
By 4 years of age, the incidence of a positive result in any food allergy test varied from 5.0 percent among babies born in June-July, to 9.5 percent among those born in October-November.
This translated to a 4-year cumulative food allergy incidence of 11.0 percent among the children whose 11th gestational week had been in April-May, compared with rates of 5.5-8.0 percent for those whose 11th week fell at other times during the year.
Of note, "the concentrations of alder and birch pollen in the area were highest in April and May [during the study period]," which Pyrhönen et al suggest as a possible explanation for their finding.
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By Sarah Guy