Aim: to study the effect of an acute mother stress reaction and anxiousness on the heart rate of the foetus. Methods and material: In this prospective research, participants were pregnant women who were not experiencing any complications with their pregnancy and carried just one baby. All pregnancies were dated using the most accurate obstetric estimate possible, which was derived from the date of the woman's most recent menstrual cycle and the foetal biometry obtained from an ultrasound during the first trimester. Results: The mean ± SD State anxiety score was 39.25±6.78 and the mean ± SD Trait anxiety score was 45.98 ± 6.39. For state anxiety, 17 subjects had a high score and 23 subjects had a low score. Table 1 For trait anxiety, 17subjects had a high score and 23 subjects had a low score. There were no significant differences in mean ± SD maternal age in either the state anxiety group (high state anxiety 32.01 ± 4.25 years versus low state anxiety 31.98 ± 2.97 years) or the trait anxiety group (high state anxiety 32.15 ± 2.87 years versus low state anxiety 32.01 ± 3.69 years). Baseline FHR showed no significant differences between fetuses of mothers with high or low state anxiety (135.69 ± 7.69 beats/min versus 135.67 ± 5.24 beats/min, respectively), or between fetuses of mothers with high or low trait anxiety (136.71 ± 5.22 beats/min versus 135.02 ± 2.87 beats/min, respectively). The response patterns of FHR after VAS were type I in 23 fetuses (57.5%), type II in 10(25%) and type III in 7 (17.5%). Conclusion: we concluded that the changes in neurobehavioral functioning that are associated with inadequate mood regulation in the mother can be identified as early as the period when the mother is still in utero.