Objectives:The impact of the gestational changes on left ventricular contractility is not clearly defined. Our aim was to evaluate the subtle changes of left ventricular systolic function during pregnancy, assessed by new echocardiographic techniques, in a population tested for inherited thrombophilia. Material and methods:Eighty seven consecutive pregnant women, with a mean age of 32±4 years, genetically tested for inherited thrombophilia (22 with thrombophilic mutations and risk of thrombosis and 65 without significant mutations, considered as the control group) were included. All participants had four clinical and echocardiographyc visits: three during pregnancy (one in each trimester) and the forth six months after giving birth. Left ventricular (LV) systolic function was assessed from ejection fraction (EF) by 2D and 3D echocardiography, mitral annular velocities by tissue Doppler, and strain rate by 2D speckle tracking. Outcomes:There were no differences between groups for any of the echo parameters at each of the four visits. Comparing the third visit with the first one, all parameters of LV systolic function had significantly lower values at the end of pregnancy; EF decreased from 58% to 55% (2D echo), from 60% to 56% (3D TomTec), and from 58% to 55% (Auto4DLVQ), with p<0.001 for all three methods. Moreover, strain assessed by speckle traking decreased during pregnancy, with no differences between groups. In addition to this, mitral annular velocities obtained by tissue Doppler assessment decreased during the gestational period, with no differences between groups. At six months after giving birth, all values were normalized. Conclusion:During pregnancy, LV contractility has a slight decrease, with no criteria of systolic dysfunction. Thrombophilic mutations, with correct anticoagulant treatment, has no impact on LV systolic function.