BACKGROUND Hypertension occurs in some 10% of pregnancies and its effects on the left ventricular (LV) morphology and systolic function have been well elucidated. Little is known, however, about the changes in LV diastolic function in such a condition. The aim of this study was to evaluate the LV diastolic function in women with pregnancy-induced hypertension (PIH) using new Doppler echocardiographic methods. METHODS Twenty-two women with PIH (mean age 31.0 +/- 4.1 years) were examined during the third trimester of pregnancy. Other 15 normotensive pregnant women (mean age 31.8 +/- 5.7 years, p = NS) were used as controls. Doppler parameters of diastolic function included: mitral inflow variables, pulmonary venous flow (PVF) variables, M-mode color Doppler of LV inflow and pulsed tissue Doppler of the mitral annulus. Furthermore, patients underwent an echocardiographic evaluation immediately after delivery and 1 month later. RESULTS PIH women showed an increased E/A ratio and an increase in the diastolic forward components of PVF. The ratio of systolic to diastolic time-velocity integral and the systolic fraction of time-velocity integrals subsequently decreased. Women with PIH also presented a significantly increased velocity of reversal PVF at atrial contraction, a decrease in the ratio between mitral and PVF duration at atrial contraction and a slower flow propagation velocity with M-mode color Doppler. LV wall thickness and mass were significantly higher in hypertensive pregnant women. In women with PIH the abnormal PVF parameters became similar to those of controls immediately after delivery, while the E/A ratio, M-mode flow propagation velocity and LV mass did so after 1 month. CONCLUSIONS Hypertension complicating pregnancy significantly affects ventricular diastolic filling. These alterations chiefly involve PVF, mitral inflow and intraventricular flow propagation velocities. The LV systolic function is preserved, in the presence of a transient LV remodeling.