HEREDITY IS THE STRONGEST DETERMINANT OF INFANTILE ATOPY; PROLONGED EXCLUSIVE BREAST FEEDING GIVES NO ADVANTAGE

Abstract

We followed 183 infants for 2 years. A short breast feeding group (F3.5) (N=32) was fully weaned by age 3.5 months (median 70 days) while group BE9 (N=31) was exclusively breast fed for 9 months. We assessed heredity for atopy, infections, and duration of breast feeding as determinants of atopy. We saw an atopic manifestation during the 1st year of life in 14 infants. The parents reported atopy-like signs during the 2nd year in another 31 infants. Heredity was the most significant predictor of atopy (30 % of heredity + infants had atopy v. 18 % of heredity -infants, p=0.04). Other significant predictors were late exposure to cow-milk and frequent upper respiratory tract infections (URTI). The type of feeding associated with atopy particularly among the heredity - infants. Of them fewer infants had atopy in group F3.5 than in group BE9 (1/19 v. 5/18, p=0.06). Furthermore, atopic manifestations during the 1st year were less common in group F3.5 (independent of heredity) than in group BE9 (0/32 v. 5/31, p=0.02). The duration of breast feeding did not associate with the frequency of URTI. Diarrhoea during the 1st year was more common in group F3.5 than in group BE9. Prolongation of exclusive breast feeding from 2 to 9 months does not contribute to prevention of infantile atopy and respiratory tract infections.