An exploratory pilot study on the effects of HRV biofeedback on pregnant women and fetuses

Pregnant women at last trimester are prone to anxiety and depression, which could exert a long-term influence on both the mother and fetuses. Managing anxiety with Heart Rate Variability Biofeedback (HRVB) is possible mechanism for its fame to strengthen homeostasis via favorably altering the activity of the autonomic nervous system. In this study, we studied the effects of HRVB on pregnant women in late pregnancy by assessing the changes of blood pressure and analyzing the changes of heart rate variability (HRV) both in pregnant women and their fetuses. 20 pregnant women without pregnancy induced hypertension and diabetes were randomly assigned to the HRVB group and the control group. Participants in the HRVB group were asked to practice HRVB for 30 minutes, while participants in the control group were asked to collect 10 minutes of HRV data without training. HRV of pregnant women (PHRV) were collected during training, blood pressure and fetal HRV (FHRV) were collected at each pregnancy test. The trial ended when participants were hospitalized for childbirth. The results proved the HRVB to be an effective intervention to modulate BP and strengthen regulation ability of ANS both in pregnant women and fetuses.