Impact of doula's continuous support on serotonin release in parturients: a pilot randomized clinical trial

Abstract Objective: To evaluate whether the continuous support provided by doulas influences the endogenous release of serotonin in parturients. Methods: This pilot study included 24 primigravidae at term. Of these, 12 women received continuous doula support (Experimental Group), whereas the other 12 received the usual assistance without doula support (Control Group). Blood samples were collected from all the women at the active and expulsion stages of labor and at the fourth period of labor (Greenberg period) for evaluation of their serotonin levels using high-performance liquid chromatography. Results: The average serotonin concentrations in the control and experimental groups were respectively 159.33 and 150.02 ng/mL at the active stage, 179.13 and 162.65 ng/mL at the expulsion stage, and 198.94 and 221.21 ng/mL at the Greenberg period. There were no statistically significant differences in serotonin concentrations between the two groups at the active and expulsion stages of labor. By contrast, within the experimental group, a significant increase in serotonin concentration was observed in the Greenberg period compared with the levels in the active and expulsion stages (p < 0.05). Conclusion: The novelty of this study relies on the ability to correlate the influence of the continuous support offered by doulas with the release of serotonin in parturients, with the results suggesting that the assistance received during labor can modulate the levels of hormone release in the Greenberg period. Brazilian Registry of Clinical Trials: RBR-4zjjm4h