No association between birth weight and Type 1 diabetes mellitus--a twin-control study.

Aims: To investigate, by means of a twin-control study, whether there is a relationship between birth weight and Type 1 diabetes mellitus.

Methods: In the youngest part (n = 20 888 pairs) of the Danish Twin Register, 95 twin pairs (26 monozygotic and 69 dizygotic) with Type 1 diabetes were identified. Information about birth weight and birth length, prematurity, maternal age and parity was obtained from midwives' records and from the Danish Medical Birth Registry and analysed using Student's two-sided t-test, Chi-square test and logistic regression.