Digital Health Tools Reduce Pregnancy Weight Gain But Fail to Boost Activity in Underserved Women

Can Digital Technologies Revolutionize Maternal Weight Management?

A mobile eHealth intervention aimed at promoting appropriate gestational weight gain (GWG) among economically disadvantaged pregnant women enrolled in Louisiana's WIC program failed to improve physical activity levels, despite successfully reducing total weight gain. The trial, conducted by researchers at Pennington Biomedical Research Center, found that physical activity decreased similarly in both intervention and control groups as pregnancy progressed, revealing the challenges of maintaining activity levels during pregnancy even with digital support tools and resources.

What Are the Key Study Design Elements and Outcome Measures?

The randomized controlled trial, which enrolled 351 pregnant women receiving WIC benefits across 31 Louisiana clinics, represents the first study to test a GWG intervention within the federal supplemental nutrition program. The multicomponent intervention included daily weight monitoring, step tracking via Fitbit, educational videos, health coach support, and a private Facebook group. While the previously reported primary outcome showed the intervention successfully reduced total and weekly gestational weight gain compared to usual care, this secondary analysis reveals limitations in influencing physical activity behaviors. "Almost all participants met physical activity guideline recommendations of at least 150 minutes per week of moderate-to-vigorous physical activity at baseline in early pregnancy, but both groups showed decreases in activity as pregnancy progressed," the researchers noted. Sedentary time increased by approximately one hour per day in both groups from early to late pregnancy, with no significant differences between intervention and control participants. The only positive movement-related outcome was a small increase in self-reported sports participation in the intervention group compared to a decrease in the control group.

Why Did Digital Support Fail to Boost Physical Activity?

The findings highlight a critical challenge in digital health interventions targeting underserved populations. Despite careful co-development of the intervention with community stakeholders to ensure cultural sensitivity and accessibility, the researchers concluded that "without supervised exercise sessions, mobile eHealth interventions promoting the national physical activity guidelines and providing resources may reduce total GWG but are unlikely to significantly impact physical activity levels during pregnancy in underserved, hard-to-reach populations." This suggests that more intensive approaches may be needed to maintain physical activity throughout pregnancy, particularly for women facing economic disadvantages. The study utilized both objective accelerometry and self-reported questionnaires to assess physical activity, providing comprehensive data on movement patterns. Participants wore wrist-mounted ActiGraph accelerometers for up to seven days in early and late pregnancy, while also completing the Pregnancy Physical Activity Questionnaire to capture contextual information about their activities.

The intervention was designed to be accessible to women with limited resources, including the provision of exercise equipment (yoga mat, resistance bands, and dumbbells), digital scales for weight monitoring, and activity trackers. Health coaches provided weekly virtual check-ins via a web-based messaging platform, offering personalized feedback based on participants' weight gain patterns and activity levels. Educational content was delivered through brief 2-4 minute videos featuring intervention staff and actors reflective of the study population. Despite these supports, engagement with physical activity components was limited, with participants in the intervention group recording their steps an average of 3.6 days per week and achieving their 5,000-step goal on only 39% of days when steps were recorded. The researchers noted that "participants took an average of 4,560 steps per day across the intervention period, which was consistent between the second and third trimesters," falling well below the commonly recommended 10,000 steps per day for general health.

How Do Socioeconomic Factors Influence the Outcomes?

The study population faced significant socioeconomic challenges, with participants living in neighborhoods that experienced greater degrees of disadvantage compared to national averages. The researchers acknowledged that "larger policy, systems, and large-scale environmental factors may be needed to maintain or increase physical activity in economically disadvantaged populations, particularly in those who are enrolled in federal programs such as WIC." The COVID-19 pandemic, which occurred during the study period, may have further complicated efforts to maintain physical activity. Interestingly, changes in physical activity did not predict GWG outcomes in this population, suggesting that other factors may have contributed to the intervention's success in reducing weight gain. The researchers hypothesized that participants may have had "greater physical demands from home chores, family responsibilities, and physically intensive jobs, rather than structured exercise," potentially explaining the disconnect between formal physical activity measures and weight outcomes.

What Are the Future Implications for Maternal Care?

This study adds to a growing body of evidence regarding the effectiveness of digital health interventions in maternal care, particularly for underserved populations. While the intervention showed promise in its primary outcome of reducing gestational weight gain, the failure to impact physical activity levels highlights the need for more comprehensive approaches that address broader social determinants of health. The researchers concluded that "our study provides empirical data in a population of pregnant women who face economic disadvantages and are engaged in a federal supplemental nutrition program, thereby providing a foundation for understanding the importance of leveraging multilevel interventions in federal assistantship programs to improve movement behaviors in pregnancy."

Industry Context: This study reflects the broader challenges in digital health interventions targeting behavioral change in underserved populations. While telemedicine and remote monitoring technologies have expanded rapidly, particularly during the COVID-19 pandemic, their effectiveness varies significantly across different health behaviors and populations. The findings suggest that technology-enabled interventions may need to be paired with more intensive in-person components or environmental modifications to achieve meaningful changes in physical activity patterns among economically disadvantaged groups. As investors and healthcare systems increasingly look toward digital solutions to address health disparities, this research highlights the importance of nuanced, multi-level approaches rather than one-size-fits-all digital interventions.

Summary

A randomized controlled trial involving 351 economically disadvantaged pregnant women in Louisiana's WIC program demonstrated that a mobile eHealth intervention successfully reduced gestational weight gain but failed to improve physical activity levels. Despite providing participants with activity trackers, educational videos, health coach support, and exercise equipment, both intervention and control groups experienced similar declines in physical activity and increases in sedentary time as pregnancy progressed. The study revealed that nearly all participants met physical activity guidelines in early pregnancy, but engagement with digital activity components remained limited, with participants recording steps only 3.6 days per week on average and achieving daily step goals just 39% of the time. Researchers concluded that without supervised exercise sessions, mobile health interventions are unlikely to significantly impact physical activity during pregnancy in underserved populations facing socioeconomic challenges. The findings suggest that more intensive, multilevel approaches addressing broader social determinants of health may be necessary to maintain physical activity throughout pregnancy, particularly for women enrolled in federal assistance programs. This research highlights important limitations of technology-based solutions in achieving behavioral change among economically disadvantaged groups, indicating that digital interventions may need to be paired with in-person components or environmental modifications to be truly effective.