During pregnancy several maternal adaptations occur in order to support the growing fetus which are further exacerbated by gestational diabetes mellitus (GDM). Previously we developed a mouse model of GDM, however we did not evaluate alterations to energy and fat metabolism. We have also shown that alterations in lipid metabolism are mediated by adrenomedullin (ADM) in normal and GDM pregnancies. Our objectives were: (1) evaluate energy and fat homeostasis in our GDM mouse model and (2) determine if ADM may play a role in these changes. Female mice were placed on either control (P-CD) or high fat, high sucrose diet (P-HFHS) 1 week prior to and throughout pregnancy. Mice were placed into comprehensive lab animal monitoring system (CLAMS) chambers throughout pregnancy. Visceral adipose tissue (VAT) was collected at d17.5 of pregnancy for analysis. Energy Expenditure was significantly increased (p < 0.05) in P-HFHS dams compared to all other groups. VAT ex-vivo lipolysis was increased (p < 0.05) in P-HFHS compared to P-CD dams. VAT gene expression of ADM receptors Crlr, Ramp2, and Ramp3 was increased (p < 0.05) in P-HFHS dams. ADM dose dependently increased ex vivo lipolysis. This data further validates our animal model of GDM and is usefulness in investigating the pathophysiology of GDM.