Length of gestation and gender are associated with HLA genotypes at risk for Type 1 diabetes (Italian DIABFIN 3)

The aim of this study, which is part of the ongoing DIABFIN project, was to correlate HLA class II genotypes, classified for their effect on susceptibility to Type 1 diabetes (T1D), with various risk factors during pregnancy and the neonatal period.

Cord blood was collected from 4349 neonates; 1.0% were at high HLA risk (HR), 9.0% at moderate HLA risk (MR), and 90.0% at low HLA risk (LR) for T1D. Information about the mother's pregnancy, type of delivery, the neonates' clinical features at birth, and family history for autoimmune diseases were collected.

Significant correlations were found between the different HLA risk categories and length of gestation, even when adjusted for sex, weight and length at birth of the neonate, birth order and mother's age (adjusted P = 0.007). The male : female ratio tended to increase from the LR to the HR category, from 1.00 and 1.21, respectively, in the LR and MR groups, to 1.62 in the HR group (P = 0.05).

Length of gestation is inversely correlated with HLA risk categories for T1D. The higher the HLA risk for T1D, the shorter the gestational age, especially in male neonates.