The process of uterine involution in postpartum mothers must proceed effectively, as any disruption may lead to uterine subinvolution, which can cause complications.

This study aimed to examine the potential of Otaria gymnastics to prevent complications postpartum and improve the welfare of postpartum mothers.

A quantitative research approach was adopted with a quasi-experimental design using pretest-posttest with the control group. The inclusion criteria involved mothers with normal pregnancies. An independent T-test was conducted to assess the effect of Otaria gymnastics on the decrease in uterine fundus height in cm and by using finger palpation. Moreover, the Chi-square test was carried out to determine the color change in the lochia and the intensity of fundus uterine contractions.

The results showed that Otaria gymnastics up to the seventh day significantly affected the decrease in the height of the uterine fundus, both by measuring in centimeters and using finger palpation. Likewise, it substantially reduced contraction intensity and changes in lochia.

These findings support the application of Otaria gymnastics as an effective intervention to prevent complications and improve the welfare of postpartum mothers in Indonesia.