Association Between Hydrotherapy During Labor and β-Endorphin Levels in Postpartum Mother's Milk.

Background: Hydrotherapy is a complementary and alternative method in childbirth widely used to reduce labor pain and stress. The birth process significantly influences levels of β-endorphin in human milk. However, the relationship between hydrotherapy during labor and β-endorphin levels in the mother's milk is unclear.

Aims: We aimed to investigate the relationship between hydrotherapy during labor, and human milk β-endorphin levels. The study also aimed to investigate the relationship between milk β-endorphin levels and maternal labor pain and birth satisfaction.

Method: We conducted a cross-sectional observational study involving a total of 84 participants who gave birth vaginally. Among them, 42 received hydrotherapy during the initial stage of labor, while the remaining 42 did not. Considering the available data, an alpha of 0.05 (Type I error), and β-endorphin concentration, our sample of 84 participants provided a power calculation of 65%. Milk samples were collected, and the Perception of Birth Scale was administered 24 hours after birth. The concentration of β-endorphin in the participant's milk and the Perception of Birth Scale were compared using Mann-Whitney U tests.

Results: The amount of β-endorphin in milk was higher for participants who received hydrotherapy than for those who did not (Mean = 503.5 pg/ml, SD = 569.2; mean = 295.7 pg/ml, SD 274 respectively; p = 0.028). The total Perception of Birth Scale scores were higher in the hydrotherapy group compared to the control group (Mean = 78.9, SD = 6.2; mean = 74.1, SD = 6.4; p = 0.001).

Conclusions: Hydrotherapy is correlated with a positive perception of birth and higher levels of β-endorphin in milk. Further research on the causal relationship between hydrotherapy and β-endorphin levels in milk may support its use to facilitate positive changes in mother's milk.