This research was a clinical trial conducted on overweight and obese pregnant women with diabetes at health centers in Ahvaz during 2023, over a ten-week period. The inclusion criteria included pregnant women aged 24 - 28 weeks, diagnosed with gestational diabetes based on a two-hour postprandial blood glucose test. Participants were required to be literate, overweight or obese (as determined by BMI at the first care visit), own a personal smartphone with WhatsApp, and be able to attend and participate in face-to-face meetings.
Exclusion criteria included the occurrence of severe complications related to diabetes, failure to adhere to the study protocols, or voluntary withdrawal by the participant. To determine the sample size, a previous study (
20) was referenced, with statistical parameters set at a power of 80% (β = 0.2) and a significance level of α = 0.05. The effect sizes were estimated with standard deviations (s1 = s2 = 1.26), and (d = 0.8), with a minimal clinically significant difference (d) of 0.8. The minimum sample size was calculated using the following formula:
The calculation resulted in a minimum sample size of (n = 78). To account for a potential dropout rate of 10%, the adjusted sample size was increased to 88 participants, with 44 assigned to the intervention group and 44 to the control group. Participants were selected using purposive sampling from all health centers in the east and west of Ahvaz, ensuring they met the inclusion criteria and did not meet any exclusion criteria.
This study recruited overweight and obese pregnant women with gestational diabetes from healthcare centers in Ahvaz, Iran. Potential participants who met the inclusion criteria were identified during their visits to the healthcare centers. The lead researcher provided a comprehensive explanation of the study procedures and ensured participants understood that their data would remain confidential. After obtaining written informed consent, participants were randomly assigned to one of two groups, each consisting of 44 individuals.
A block randomization method was employed to achieve balanced group sizes and minimize selection bias. Blocks of a predetermined size (8 participants per block) were created to facilitate an equal distribution of participants between the two groups. A random number generator was used to assign participants to either the control group, which received routine prenatal care, or the intervention group, which received both routine prenatal care and an educational program delivered via a mobile application. Each block was randomized independently to maintain the integrity of the random assignment throughout the recruitment process.
At baseline (between 24 and 28 weeks of gestation), a checklist of blood glucose tests (fasting blood sugar and 2-hour postprandial blood glucose) was completed for all participants. Blood glucose levels were measured and interpreted before and after the intervention based on the American Diabetes Association's criteria as of January 1, 2021. These criteria included fasting blood glucose levels of 92 mg/dL or higher, blood glucose levels of 180 mg/dL or higher one hour after consuming 75 grams of glucose, and blood glucose levels of 153 mg/dL or higher two hours after an oral glucose tolerance test (OGTT) with 75 grams of glucose (
21). Additionally, demographic data and questionnaires assessing physical activity, lifestyle, and self-care behaviors were collected.
Subsequently, women in both groups received routine care provided by the health centers until delivery. In addition to the face-to-face education offered by the health center's midwife as part of routine prenatal care, the intervention group received additional education via a software application. A WhatsApp group was created for the intervention group, where participants received two educational messages daily (on even-numbered days) over a 10-week period. These messages included text, images, and videos, with content aligned with the in-person educational sessions. Both the in-person and online education covered topics such as gestational diabetes, its complications, self-care strategies, nutrition (including dietary restrictions and portion sizes), physical activity, and insulin administration. Recommended exercises included walking, rhythmic movements, stretching, Pilates, and prenatal classes.
To monitor the effectiveness of the educational intervention, participants were contacted by telephone throughout the study and informed that they could reach out to the researcher for additional support. At 38 weeks of gestation, all participants underwent an OGTT and FBS test. The results were recorded, and participants completed follow-up questionnaires on physical activity, lifestyle, and self-care behaviors. Weight changes were also assessed.
Data were collected using a demographic questionnaire, a blood glucose test checklist, maternal weight measurements, and weight change recordings, along with the International Physical Activity Questionnaire (short form), a lifestyle questionnaire, and the Diabetes Self-Care Activities Scale. The demographic questionnaire consisted of two sections: Sociodemographic characteristics (e.g., age, education, occupation) and obstetric history (e.g., number of pregnancies, gestational age, miscarriages).
The Diabetes Self-Care Activities Scale, developed by Toobert et al., was used to assess self-care behaviors in individuals with diabetes. This 15-item scale evaluates self-care behaviors across four domains (diet, exercise, blood glucose monitoring, and insulin injection) in its original version, and five domains (diet, exercise, blood glucose monitoring, foot care, and smoking) in a later version. The scale employs a 7-point Likert scale, ranging from 0 (no self-care activities in the past seven days) to 7 (performed all self-care activities in the past seven days). For instance, smoking is scored as 0 if the participant smoked and 7 if they did not. The maximum possible score is 78, with higher scores reflecting better self-care (
22). The Bahasa Indonesia version of the Summary of Diabetes Self-Care Activities (SDSCA) demonstrated excellent content validity (CVI = 0.98) and acceptable reliability (Cronbach's alpha = 0.72) (
23). Nouhi et al. adapted and validated this scale in Iran, showing good content validity and reliability (Cronbach's alpha = 0.89) (
24).
The International Physical Activity Questionnaire (IPAQ) is a globally recognized instrument for assessing physical activity levels. It includes questions about an individual's work-related physical activity, transportation, housework, and leisure activities over the previous seven days. Developed in 1998 by the World Health Organization and the Centers for Disease Control and Prevention for individuals aged 15 - 69, the IPAQ utilizes a 27-item self-report format with four sections: Job-related activity (7 items), transportation (6 items), leisure-time activities (6 items), and time spent sitting (8 items). It assesses light, moderate, and vigorous physical activity levels and walking over the past week. A scoring protocol converts this information into MET-minutes/week, a unit used to estimate energy expenditure during physical activity. One MET corresponds roughly to the energy expenditure of a person at rest. The short form of this questionnaire was used in the present study.
In this study, physical activity levels were categorized as follows:
- Intense physical activity: Engaging in any combination of light, moderate, or walking activities for at least seven days a week, totaling a minimum of 3000 MET-minutes per week.
- Moderate physical activity: A combination of walking, moderate, or light activities for at least five days a week, amounting to at least 600 MET-minutes per week.
- Light physical activity: Reporting no physical activity or engaging in activities that did not meet the criteria for moderate or vigorous activity (
25).
The IPAQ has been widely validated across various populations, demonstrating good test-retest reliability [(rw = 0.74)] and moderate concurrent validity [(rw = 0.72)] (
26). The validity of the questionnaire was further confirmed by Vaghani-Farahani, who reported a reliability coefficient of 0.83 (
27).
The lifestyle questionnaire used in this study comprised 70 items designed to assess various lifestyle dimensions, including physical health, exercise and fitness, weight control and nutrition, disease prevention, mental health, spiritual health, social health, medication and substance abuse avoidance, accident prevention, and environmental health. It utilized a Likert scale response format across ten dimensions. To calculate a score for each dimension, the corresponding question scores were summed, and the overall questionnaire score was derived by summing the scores from all questions. The possible scores ranged from 42 (lowest) to 211 (highest). Based on this scoring system, three lifestyle levels were designated: Unfavorable (48 - 98), moderate (99 - 155), and favorable (156 - 211).
The study by Eshaghi et al. demonstrated the questionnaire's reliability (Cronbach’s alpha = 0.76) and its effectiveness for assessing healthy lifestyle patterns among the Iranian elderly (
28). Additionally, Lali et al. validated the construct validity of the lifestyle questionnaire as a multidimensional tool for assessing lifestyle using factor analysis. The questionnaire's reliability was further confirmed with a Cronbach's alpha coefficient of 0.78 (
29).
Following the completion of the initial questionnaires, a needs assessment was conducted. Educational content and a training package, including videos, photos, and texts, were developed and tailored based on the identified needs. Data analysis for the study was performed using SPSS version 22. A chi-squared test was utilized to assess the homogeneity of the two groups concerning categorical demographic variables. Before conducting parametric tests, the assumption of normality was verified using the Kolmogorov-Smirnov test, and the assumption of homogeneity of variances was examined using Levene's test. After confirming these assumptions, an independent samples t-test was conducted to examine between-group differences, while a paired samples t-test was used to investigate within-group differences at pre- and post-intervention stages. The significance level was set at 0.05.