Intrauterine growth pattern and risk of childhood onset insulin dependent (type I) diabetes: population based case-control study

Abstract

Objective: To investigate whether prenatal growth affects the risk of development of childhood onset insulin dependent (type I) diabetes mellitus. Design: Population based case-control study. Setting: Data from a nationwide childhood diabetes case register were linked with data from the nationwide Swedish Medical Birth Registry. Subjects: Data from a total of 4584 diabetic children born after 1973 and diagnosed with diabetes from 1978 to 1992 were studied. For each child with insulin dependent diabetes three control children were randomly selected from among all infants born in the same year and at the same hospital as the proband. Main outcome measures: Birth weight, gestation, maternal age and parity, number of previous spontaneous abortions, and sex specific birth weight by gestational week expressed as multiples of the standard deviation (SD). Results: There was a clear trend in the odds ratio for childhood onset diabetes according to SD of birth weight. The odds ratio (95% confidence interval) for small for gestational age after stratification for maternal age, parity, smoking habits, and maternal diabetes was 0.81 (0.65 to 0.99) and for large for gestational age after similar stratification was 1.20 (1.02 to 1.42). Conclusions: Intrauterine conditions that affect prenatal growth seem also to affect the risk of development of childhood diabetes in the way previously described for postnatal growth: a poor growth decreases and an excess growth increases the risk. The mechanism for this association is unclear. By linking two nationwide population based reg- isters the effect of intrauterine growth on the risk for childhood onset insulin dependent diabetes is estimated There was a clear trend in the risk for childhood onset diabetes according to differences in birth weight by gestational age expressed as multiples of SD from population means The adjusted odds ratio for babies who were small for gestational age was significantly decreased and for large for gestational age babies was significantly increased A poor intrauterine growth decreases and an excess growth increases the risk of development of childhood insulin dependent diabetes