Using data from a large study of British births in 1958, researchers set out to test whether a father's non-insulin dependent diabetes or a mother's diabetes starting after childbirth was associated with the birth weight of their offspring.
The offspring of the fathers with diabetes weighed on average 186 g less than other children. Father's adult height or social class did not explain the association between a father's diabetes and the birth weight of his offspring. The child's birth order also made no difference to the effect of a father's diabetes on the birth weight of his offspring, say the authors.
In contrast to the paternal effect, active diabetes in the mother increases the birth weight of offspring, they add.
"Our findings support the hypothesis that common genetic factors contribute both to the risk of non-insulin dependent diabetes and decreased prenatal growth," they conclude.