The Storytelling video intervention created is approximately 20 minutes long.

Routine hospital protocol was applied to the women in this group. Storytelling fertility awareness video intervention was also given to the control group after the study.

A storytelling fertility awareness video intervention, approximately 10 minutes in length, guided by a situation-specific theoretical framework and storytelling/narrative communication theory, was developed by the researchers.

Paternal Breastfeeding Self-Efficacy Scale- Short Form (Paternal BSES-SF): Paternal BSES-SF was developed by Dennis et al. (2018) to measure paternal self-efficacy in supporting their wives in breastfeeding and Cronbach's alpha value was 0.92. A Turkish validity-reliability study was conducted by Küçükoğlu (2022) and Cronbach's alpha value was found to be 0.93. The scale was applied to all fathers with newborn and breastfed infants and consisted of a single dimension with 14 items evaluated on a 5-point Likert scale (1=never 2=sometimes 3=sometimes 4=often 5=always). There are no reverse scored items in the scale. The minimum score to be obtained from the scale is 14 and the maximum score is 70. The cut-off point of the scale has not been determined,higher scores indicate higher confidence.