Abstract Body: The rates of hypertensive pregnancy disorders such as gestational hypertension, pre-eclampsia/eclampsia (PE/E), and chronic hypertension with or without superimposed PE have increased in recent years. Cerebrovascular disorders in the antenatal and postpartum period are common complications of hypertensive pregnancy disorders. Chronic hypertension is linked to cerebrovascular rarefaction, decreased regional perfusion, and cognitive decline later in life. The blood pressure high 5 (BPH/5) mouse has been characterized as a model of superimposed PE; however, cerebrovascular changes have not been described. We hypothesized that BPH/5 mice will display reduced regional cerebral perfusion regardless of pregnancy status. To test this, we used non-pregnant and timed-pregnant BPH5 mice and control SMA-GFP mice (C57/BL6 background) (n=3-4 per group). On gestational day 18.5, cerebral perfusion was measured using laser speckle imaging in different brain regions, along with general physiological characteristics (heart rate and oxygen saturation), body, heart, and brain weight, and the number and weight of live fetuses. There was a main effect of pregnancy to increase body weight (p<0.01), hematocrit (p=0.04), and sPO2 (p=0.02). There was a strain effect on sPO2 (p<0.01), heart rate (p<0.01), perfusion of right parietal cortex (p=0.02), whole brain (p<0.01), prefrontal cortex (p<0.01), with significant decreases in pregnant BPH5 compared to pregnant SMA-GFP mice (p<0.05). There was no difference in number (8±1 vs 6±2) and mean body weight (1021±24 vs 883±160 mg) of live fetuses between control vs. BPH5 mice (Mean ± SD). These results support the hypothesis chronic hypertension and superimposed PE lead to reduced cerebral perfusion. Future studies will determine whether reduced cerebral perfusion is associated with cerebrovascular rarefaction and whether these are blood pressure dependent.