- We characterised the 24-h arterial pressure (AP) profile and the left ventricular (LV) structures and functions in pregnant women with pregnancy-induced hypertension (PIH) or gestational diabetes mellitus (GDM). Thirty pregnant women after 20 weeks' gestation--(10 normotensive; 10 with PIH; and 10 with GDM)--were investigated haemodynamically using 24-h AP monitoring and Doppler echocardiography for determination of LV structures and functions, both systolic and diastolic. The PIH women had significantly higher AP determinations throughout the 24 h, with no change in the diurnal variation, ie, nocturnal decline and early morning peaks. The LV mass was greater in PIH and GDM than in the normotensive women, despite normal AP in GDM. The increased LV mass in GDM was mainly due to LV dilatation and not to increased thickness of its walls. In PIH, the increase in AP was due to peripheral vasoconstriction, while cardiac output was preserved. The LV systolic functions did not differ among the three groups. However, a slight reduction in the myocardial contractility was found in PIH and GDM. The LV relaxation was significantly impaired in both PIH and GDM. Thus, GDM and PIH, although differing in their 24-h AP profile, are characterised by LV hypertrophy and reduction in diastolic function.