In addition to routine physician check-ups, an SMS group was created for the individuals in the intervention group, and basic information messages for diabetes control were sent to this group at regular intervals. In addition, individuals asked questions via this group. At the end of the eight-week follow-up, the data collection forms were filled out again and the study was terminated.

The same data collection forms were filled out at the first interview and eight weeks later by the pregnant women in the control group, and they continued to receive routine follow-ups.

In addition to routine physician check-ups, an SMS group was created for the individuals in the intervention group, and basic information messages for diabetes control were sent to this group at regular intervals. In addition, individuals asked questions via this group. At the end of the eight-week follow-up, the data collection forms were filled out again and the study was terminated.

This scale was first developed by Dunn et al.13 to measure diabetes knowledge. Afterward, it was developed by Carolan et al. to examine three effect domains: pregnant women's GDM knowledge, nutritional values, and GDM self-management principles. The scale consists of 18 questions. Cronbach's alpha value of the total scale was determined as 0.654.

This is a five-point Likert-type scale consisting of 23 items developed by Polat and Avdal in 2019 to evaluate the self-efficacy levels of individuals with gestational diabetes. It consists of four sub-dimensions: "diet-weight management"; "complication measures"; "compliance with nutrition education"; "medical therapy practices". As the total score on the scale increases, the level of self-efficacy increases, as well. Cronbach's alpha value of the total scale was determined as 0.654.