Seasonal differences in breast-feeding in rural Egypt.

Two surveys in Upper and Lower rural Egypt allowed an analysis of the seasonality of infant feeding. The first, including 937 children, was conducted during the relatively cool season of low diarrhea incidence in January-April 1978; the second, including 976 children, took place during the hot season of high diarrhea incidence in August-September 1980. Of infants 6-11 mo old, the proportion exclusively breast-feeding was greater in the hot-season survey (40% vs 16% in Lower Egypt, p less than 0.01; 36% vs 22% in Upper Egypt, p less than 0.01). Of children 12-17 mo old, a higher proportion were completely weaned during the hot season in Lower Egypt only (28% vs 14%, p less than 0.01). This difference was explained by an increase in pregnancy rates during the hot season resulting in less breast-feeding. Seasonal variation must be considered in the interpretation of infant-feeding surveys.