Changes in salivary oxytocin after inhalation of clary sage essential oil scent in term-pregnant women: a feasibility pilot study

Abstract

Objectives: This pilot study using a quasi-experimental design was conducted to evaluate the feasibility (i.e., limited efficacy, practicality, and acceptability) of our intervention protocol involving inhalation of the scent of clary sage essential oil by pregnant women and measurement of their preinhalation and postinhalation oxytocin levels.

Results: Participants were women of singleton pregnancies between 38 and 40 gestation weeks (N = 11). The experiment group (n = 5) inhaled the scent of clary sage essential oil diluted 50-fold with 10 mL of odorless propylene glycol for 20 min. Regarding limited efficacy, the oxytocin level 15 min postinhalation increased in 3 women and was unmeasurable in 2. The control group (n = 6) inhaled similarly without the 50-fold dilution of clary sage essential oil. Their oxytocin level increased in 2 women, decreased in 2, and was unmeasurable in 2. Uterine contraction was not observed in both groups. Regarding practicality, 3 of the 11 women could not collect sufficient saliva. The cortisol level decreased in both groups postinhalation. The protocol had no negative effects. Regarding acceptability, burden of the protocol was not observed. Trial registration The Clinical Trials Registry of University Hospital Medical Information Network in Japan-UMIN000017830. Registered: June 8, 2015.

Keywords: Aromatherapy; Clary sage essential oil; Complementary and alternative medicine; Feasibility study; Induction of labor; Inhalation; Pregnant women; Salivary cortisol; Salivary oxytocin; Uterine contraction.

Fig. 1

Changes in preinhalation and postinhalation oxytocin levels. Left: Experiment group, n = 5, E4 and E5 are not shown because the oxytocin levels at all the time points were unmeasurable; Right: Control group, n = 6, C5 and C6 are not shown because the oxytocin level at all the time points were unmeasurable. Comparison within groups, no significant differences in the oxytocin levels were found between preinhalation and postinhalation (experiment group: p = 0.241; control group: p = 0.682). Comparison between groups, no significant differences were found in the preinhalation levels of oxytocin (p = 0.310) and the changes between preinhalation and 15 min (p = 1.000), 30 min (p = 0.190), and 60 min (p = 0.690) postinhalation

Fig. 2

Changes in preinhalation and postinhalation cortisol levels. Left: Experiment group, n = 5, E3 and E5 are not shown because the cortisol levels at all the time points were unmeasurable. Right: Control group, n = 6