In the largest of the postpartum studies, focused solely on T1DM, Ostrom et al. [26] also showed no difference in PRL between women with T1DM, non-diabetic controls matched for key clinical factors, and healthy reference women at days 3, 14, or 42 of lactation, but did find that women with more ‘severe’ T1DM physiology (longer-standing disease and more complications) had lower PRL at day 42 than their counterparts with less complicated disease. This evidence concerns the gene PRL and type 1 diabetes mellitus.