Gestational diabetes mellitus (GDM) and obesity are two of the most prevalent complications of pregnancy; these conditions are associated with a range of adverse maternal and fetal outcomes and long-term maternal cardiovascular risk. Although the literature is limited, a number of studies have demonstrated cardiovascular maladaptation in pregnancies complicated by GDM or obesity compared with normal pregnancies. Women with GDM had a significant reduction in cardiac output, cardiac index, stroke volume and inotropy index and an increase in total vascular resistance and in arterial stiffness from the second trimester until term with respect to normoglycemic pregnancies; obese pregnant women had a different haemodynamic profile, altered cardiac geometry, and impaired diastolic indices compared with pregnant women with a normal body mass index. The biological mechanisms underlying the haemodynamic alterations observed in pregnant women with obesity are complex and multifactorial. The impact of these changes on long-term maternal cardiovascular disorder risk and perinatal outcome remains to be determined.