Background: Cortisol has been used to capture psychophysiological stress during childbirth and postpartum wellbeing. We explored the effect of a brief antenatal training course in self-hypnosis on salivary cortisol during childbirth and 6 weeks postpartum.
Methods: In a randomized, controlled trial conducted at Aarhus University Hospital Skejby Denmark during the period January 2010 until October 2010, a total of 349 healthy nulliparous women were included. They were randomly allocated to a hypnosis group (n = 136) receiving three one-hour lessons in self-hypnosis with additional audio-recordings, a relaxation group (n = 134) receiving three one-hour lessons in various relaxation methods with audio-recordings for additional training, and a usual care group (n = 79) receiving ordinary antenatal care only. Salivary cortisol samples were collected during childbirth (at the beginning of the pushing state, 30 minutes, and 2 hours after childbirth), and 6 weeks postpartum (at wake up, 30 minutes after wake up, and evening). Cortisol concentrations were compared using a linear mixed-effects model. Correlations between cortisol concentrations and length of birth, experienced pain and calmness during birth were examined by a Spearman rank correlation test.
Findings: During childbirth, week correlations were found between cortisol concentrations 30 minutes after childbirth and length of birth. In the beginning of the pushing state and 2 hours after childbirth, we found a tendency towards higher cortisol concentrations in the hypnosis group compared to the other two groups (hypnosis versus relaxation p = 0.02 and 0.03, hypnosis versus usual care p = 0.08 and 0.05). No differences were observed in cortisol concentrations between the groups 30 minutes after childbirth (hypnosis versus relaxation p = 0.08, hypnosis versus usual care 0.10) or 6 weeks postpartum (hypnosis versus relaxation: p = 0.85, 0.51, and 0.68, hypnosis versus usual care: p = 0.85, 0.93, and 0.96).
Conclusion: Antenatal hypnosis training may increase the release of cortisol during childbirth with no long-term consequences. Further research is needed to help interpret these findings.