The evaluation of the use of herbal substances in the baths of labouring women : a randomised controlled trial : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Midwifery at Massey University
The purpose of this research was to study the progress of labour following the administration of the essential oil of ginger into the bath water of multiparous women who have experienced a previous vaginal birth. The woman's perception of pain and the amount of analgesia used were also assessed. The method used for the study was a Randomised Controlled Double Blind Clinical Trial. The women in the experimental group received the essential oil of ginger and the women in the control group the essential oil of lemongrass. On admission in labour to delivery suite the consenting women were randomly allocated to either the experimental or the control group. The data were collected using three instruments: 1) a structured questionnaire for demographic data, 2) the visual analogue scale used to measure the intensity of the pain when the woman was in the bath, 3) the McGill Pain Questionnaire used 24 hours postpartum to describe and measure the individual's pain experience. The results were analysed using the SAS PROC NPARIWAY programme and interpreted using the heading of cervical dilatation, contractions, the length of time in labour, pain and safety. There was no significant statistical difference between the two groups of women for all categories analysed with the exception of the second stage of labour. The women in the experimental group had a shorter second stage of labour than those in the control group (P=0.0142). There were no adverse affects on the women. All of the babies had Apgar scores of 9 at one minute and remained with their mothers following birth. Both groups of women rated their labour pain as severe. Due to the sample size being greatly reduced, N=22 instead of N=116, a type two error exists thus affecting the power of the study. This research should therefore be considered as a pilot study.