The influence of fetal heart rate monitoring on endocrinological parameters (growth hormone, insulin, cortisol, dopamine, epinephrine and norepinephrine) for stress was tested in women during pregnancy and in labor. Significant increases in the levels of all hormones except dopamine were found during monitoring in women with the non-stress test in comparison with the control group. Increases of more than 50% in the level of all hormones were found during labor with or without monitoring, reflecting stress during labor. The implication of fetal heart rate monitoring on the emotional state of the pregnant woman must be taken seriously.