# A randomized digital behavioral intervention for prenatal and postpartum weight outcomes in women with overweight or obesity: the GROWell trial

## TL;DR

A mobile app and text-based intervention called GROWell was tested to help pregnant and postpartum women manage weight, but it did not significantly reduce weight gain or retention compared to a control group.

## Contribution

The study is one of the few randomized trials evaluating a digital behavioral intervention for weight outcomes in pregnant and postpartum women with overweight or obesity.

## Key findings

- Excess gestational weight gain occurred in 36% of the control group and 35% of the GROWell group.
- Postpartum weight retention was observed in 26% of the control group and 23% of the GROWell group.
- Both groups had lower rates of excess weight outcomes compared to national and international averages.

## Abstract

Rising rates of overweight and obesity globally have led to an increasing number of women who enter pregnancy with excess weight, posing significant health risks to mothers and infants. Mobile health interventions, such as smartphone apps, may be a solution to improving pregnancy outcomes, however, limited randomized studies have examined this approach for gestational weight gain (GWG) and postpartum weight retention (PPWR). We report results from a double-blinded, randomized control trial of Goals for Reaching Optimal Wellness (GROWell), a mobile app and text-based intervention designed to improve diet quality and associated weight outcomes in pregnant and postpartum women.

Women living in California with BMI = 25–42 kg/m2 and a singleton, uncomplicated pregnancy were recruited via social media or clinic in early pregnancy from January 2021 through March 2023. After completing a baseline survey, participants were randomized to GROWell or an educational control. Participants completed online surveys of diet quality and other health behaviors and self-weighed using study-provided Bluetooth scales. Modified Poisson regression tested for differences in excess GWG and 6-month PPWR.

Using block randomization in permuted blocks of three based on prepregnancy BMI, race/ethnicity, and recruitment source) 453 racially and ethnically diverse participants (237 attention control, 216 intervention) were enrolled. Mean age was 33.6 ± 4.1 years and mean BMI was 30.9 ± 4.28 kg/m2. Excess GWG was observed in 36% of the control group and 35% of the intervention group. PPWR was observed in 26% of the control group and 23% of the intervention group.

Compared to an attention control, GROWell was not associated with lower rates of excess GWG or PPWR. However, study rates of excess GWG and PPWR were lower in both groups compared to averages in the US and several Western nations. Future studies should investigate the potential of text-based educational support on weight and other health indicators among childbearing women.

ClinicalTrials.gov identifier NCT04449432. Registered on June 26, 2020.

The online version contains supplementary material available at 10.1186/s12884-026-08846-3.