[A randomized controlled trial of weight management based on mobile health techno-logy among overweight or obese pregnant women].

Objective: To evaluate the effect of lifestyle interventions based on mobile health technology on gestational weight gain among overweight or obese pregnant women, to explore the influencing factors of the intervention effect, and to provide scientific evidence for weight management during pregnancy.

Methods: The randomized controlled trial (RCT) design was used. From April 2024 to August 2024, 200 singleton overweight or obese pregnant women aged 18-40 years in early pregnancy were recruited and stratified block-randomized according to body mass index (BMI) categories, age, and parity. The control group received routine prenatal care, while the intervention group received lifestyle interventions based on mobile health technology, which included biweekly face-to-face or telephone sessions; weekly recording of dietary behavior goals with personalized feedback on WeChat public account; 6 000 steps per day and 150 minutes of brisk walking per week; and weekly weight recording with personalized feedback. Based on the intention-to-treat principle, generalized linear mixed models were used to analyze the effects on weight gain and weight gain rate up to 24-28 gestational weeks, gestational diabetes mellitus (GDM), and dietary and physical activity behaviors. Additionally, subgroup analysis and interaction analysis were conducted to explore whether intervention effects on weight gain varied by different maternal characteristics.

Results: The mean age of the women in the intervention and control groups was (30.49± 3.99) years and (29.83±3.95) years, respectively, with gestational weeks at enrollment being (11.35±1.61) weeks and (11.26±1.52) weeks. No statistically significant differences were observed in the baseline characteristics between the two groups (P>0.05). In the study, 10 and 12 participants were lost to the follow-up in the intervention and control groups, respectively, with 178 women completing the midterm follow-up. At the midterm follow-up (24-28 weeks), the weight gain in the intervention and control groups was (5.00±3.72) kg and (6.57±4.28) kg, respectively. After adjusting for age, parity, gravidity, region, pre-pregnancy BMI categories, and socioeconomic status, the between-group difference was -1.63 kg (95%CI: -2.80 to -0.46; P=0.007). The adjusted between-group difference in weight gain rate was -0.07 kg/week (95%CI: -0.11 to -0.02; P=0.005). Compared with the control group, the intervention group had lower fasting blood glucose at the oral glucose tolerance test (OGTT) by 0.19 mmol/L (95%CI: 0.04 to 0.33; P=0.013). No significant difference was observed in GDM incidence between the two groups. Among different subgroups based on characteristics, such as age, region, socioeconomic status, and parity, there was no statistically significant dif-ference in the effect on weight gain.

Conclusion: The lifestyle interventions based on mobile health technology effectively controlled weight gain up to 24-28 gestational weeks among overweight or obese women and improved fasting blood glucose level. This has significant public health implications for improving the health of overweight or obese pregnant women in China.