Impact of a smartphone app supporting a lifestyle intervention in overweight and obese pregnancy on on maternal health and lifestyle outcomes

OBJECTIVE: Pregnancy offers an opportunity to encourage positive lifestyle changes. Mobile health (mHealth) technologies can assist lifestyle interventions but there is limited evidence of their effectiveness in pregnancy. The aim of this study is to examine smartphone app usage supporting a behavioral lifestyle intervention in overweight and obese pregnancy, and its impact on dietary intakes, physical activity and health outcomes. STUDY DESIGN: This is an analysis of data from participants (n=278) allocated to the intervention group of a randomised controlled trial for behavior‐change in pregnancy. The intervention consisted of face‐to‐face low glycaemic index‐based dietary advice and physical activity advice with support from a smartphone app. App usage data (times, dates and pages accessed within the app) was collected from the developers' online repository on study completion. Self‐reported dietary and physical activity data were collected at 28 weeks' gestation using 3‐day food records and a validated questionnaire. Maternal outcomes examined were insulin resistance, fasting glucose, c‐peptide, gestational diabetes incidence at 28 weeks', and gestational weight gain. RESULTS: From the 278 participants randomised to the intervention group, 76 never used the app and 5 only used the app on the day it was downloaded (considered non‐app‐users), 197 used the app on at least 2 days (considered app‐users). Maternal characteristics did not differ between app‐users and non‐users. At 28 weeks' gestation, app‐users had significantly better diet quality score (57.7 vs. 52.2, P = 0.01), lower glycaemic index (56.1 vs. 58.0 P = 0.03) and less energy from free sugars (6.7 vs. 8.1, P = 0.04) than nonusers. There were no statistically significant differences in physical activity nor maternal outcomes between the two groups. Examining level of engagement, diet quality score was significantly higher among those with high‐app‐use versus non‐app‐users (58.0 vs. 52.2, P = 0.032). CONCLUSION: Use of a smartphone app supporting a behavioral lifestyle intervention significantly improved dietary behaviours in overweight and obese pregnancy and should be considered a key component in the design of antenatal interventional trials.