*2.5. Statistical Analyses*

Statistical analyses were conducted using SPSS version 27 (IBM, Armonk, NY, USA) and setting the level of significance at 0.05.

First, Student's *t*-test for continuous variables or chi-square (*χ* 2 ) for frequencies were used to evaluate any socio-demographic or clinical differences between experimental and control group and assess whether the two groups were comparable.

Then, Student's *t*-test was performed to evaluate the differences between the experimental and control groups in the mean scores on perceived pain and anxiety during different stages of labor. The effect size was calculated with Cohen's *d* [37] (small effect size = 0.01, medium effect size = 0.06, and large effect size = 0.14).

Finally, a repeated measures ANOVA was performed to evaluate the effect of "Study Group" (experimental vs. control), "Time" (i.e., the three phases of labor), and "Childbirth Group" (primiparas vs. multiparas) on pain and anxiety. The effect size, in this case, was calculated with Cohen's *η* 2 [37] (small effect size = 0.01, medium effect size = 0.06, and large effect = size 0.14).
