Month of birth and subsequent development of type I diabetes (IDDM)

The aim of this study was to find out whether there is a seasonal pattern i n the month of birth of children with IDDM in Israel and whether this patte rn, if present, differs from that of total live births, One thousand and ni nety-five out of 1188 children and adolescents (0-17 years) who developed I DDM in Israel between 1980-1993 and whose month of birth was known were inc luded in the study. Separate analysis was made for Jews (n = 987) who have a high incidence (10-18/10(5)) and Arabs (n = 108) with a low incidence (2. 9/10(5)) of IDDM. The pattern of total live birth distribution in Israel ov er a 20-year period served as control. A significantly different seasonal p attern was found in the two IDDM populations. Whereas the Jews had the lowe st number of births in winter (January-March) and the highest in spring (Ap ril-June), the Arabs presented an inverse pattern in the first months of th e year. The distribution of births of the children who developed IDDM was d ifferent from that observed in total live births in the Jewish population, The findings in the Jewish population in Israel (a high incidence group) su pport the hypothesis that IDDM is triggered in some children by viral infec tions transmitted by the mother during pregnancy or in the early postnatal period. In the Arab population (a low incidence group) a protective (immune and/or genetic) mechanism may exist.