Background The intrauterine environment strongly influences adult disease susceptibility. We utilized a rat model of third trimester maternal diabetes to test the hypothesis that adult offspring exposed to hyperglycemia in utero display increased blood pressure and alterations in vascular responsiveness. Methods Diabetes was induced by streptozotocin injection to pregnant rats on gestation day 13 (term 21 day) and partially controlled with insulin injections. Hemodynamic function was evaluated in 6–12 month old offspring. Results Male but not female offspring of diabetic mothers (ODM) had significantly increased blood pressure compared to controls, heart rate was similar. For both sexes, heart rate baroreflex responses were similar as were in vivo hemodynamic responses to angiotensin II, NOS inhibition and ganglionic blockade. Aortic contractility to angiotensin II was similar in both groups. NOS inhibition and the Cu/Zn superoxide dismutase (SOD) inhibitor diethyldithiocarbamate but not the SOD-mimetic Tempol significantly increased contractile responses to angiotensin II in controls but not ODM. NADPH stimulated superoxide production was greater in male ODM than controls (p<0.05). Conclusions Exposure to hyperglycemia in utero results in sex specific cardiovascular changes in adult offspring. Impaired NO - reactive oxygen species signaling may play a significant role in the hemodynamic phenotype of ODM.