A number of pregnant women all over the world suffer from depression and are treated during gestation with antidepressants, mostly with selective serotonin reuptake inhibitors or selective serotonin and norepinephrine reuptake inhibitors. Exposure to prenatal stress is also a great risk factor for a developing fetus and could be responsible for altered fetal development or various neurobehavioral disturbances of a child. Administration of selective serotonin and norepinephrine reuptake inhibitor venlafaxine is associated with various cardiovascular adverse effects, such as tachycardia, increased blood pressure, arrhythmias and hypertensive crisis. The aim of this study was to focus on the effect of pre-gestational chronic mild unpredictable stress and/or administration of antidepressant venlafaxine (10 mg/kg/day, p. o.) on specific parameters, determining the function of the cardiovascular system of male and female rat offspring. Blood pressure and standard ECG were recorded in the offspring. Exposure to pre-gestational stress did not cause significant changes in the systolic, diastolic blood pressure and pulse frequency either in males or in females, compared to the unexposed control animals. Pre-gestational stress caused the shortening of QT interval and prolongation of QRS complex duration in males. On the other hand, in females, the effects of pre-gestational stress were potentiated by the administration of venlafaxine and resulted in elevated systolic and diastolic blood pressure, prolonged QT interval and shortened QRS complex duration, compared to the control. In conclusion, the female rat offspring are more sensitive to exposure to pre-gestational, to chronic mild unpredictable stress and venlafaxine.