PPARG and type 2 diabetes mellitus: We note that the common fetal variant rs1801282 in PPARG, which is associated with type 2 diabetes risk in adulthood62 via a fat distribution-mediated form of insulin resistance63, is weakly associated with lower birth weight (p = 0.0259)5 and was not associated with gestational duration in a fetal GWAS of gestational duration in 84,689 individuals (p = 0.487)64.