Use of information and communication technology -based health behavior change support system in modifying lifestyle after delivery among women with obesity.

Postpartum weight retention is common and particular when accompanied with prior obesity, it further increases the risks of subsequent pregnancies and adverse effects on the long-term health.

The aim of this randomized controlled trial is to examine whether using an information and communication technology (ICT) -based health behavior change support system (HBCSS) reduce postpartum weight retention and disorders related to subsequent pregnancy. Web-based HBCSS application utilizes persuasive design and cognitive behavioral therapy.

200 participants with prepregnancy obesity (BMI ≥ 30.0 kg/m^2) and age ≥ 18 years are randomly assigned into two groups after delivery in the Oulu university hospital. The study period begins 5-12 weeks after delivery. All participants will have conventional postpartum lifestyle counselling and the intervention group get in addition access for 12 months to web-based HBCSS application, which is recommended to use twice a week for 5-10 minutes.

Participants are followed by questionnaires up to 24 months. The main outcome is weight change from baseline to 12 and 24 months. Medical records and national registers are used for long-term follow-up. Researchers have permission to contact participants afterwards. The ethical approval is permitted by the Regional Medical Research Ethics Committee of the Wellbeing Services County of North Ostrobothnia. The authorization for the use of medical device is granted from the Finnish Medicines Agency. Recruitment of the participants will be performed 2/2024-1/2026.

Inclusion Criteria:

• Pre-pregnancy BMI ≥ 30.0 kg/m^2
• Smartphone user

Exclusion Criteria:

• Eating disorder
• Severe mental disorder
• Use of other lifestyle support system or medication
• Non-Finnish speaker