The txt4two intervention content was developed according to evidence-based guidelines. The Institute of Medicine (IOM) GWG guidelines [4] provided the GWG
recommendations. The nutrition content is based on the
recommendations of the Australian Dietary Guidelines
for pregnancy [41] with emphasis on replacement of
sugar-sweetened beverages, increased fruit and vegetable
intake, reduction of discretionary food groups and consumption of regular meals. The physical activity components are also based on national guidelines for pregnancy
[42,43]. The emphasis is on 30 minutes of moderate intensity physical activity on most, if not all, days of the week,
reduction of sedentary behaviour and abdominal and
pelvic floor strengthening. The behaviour change guidance is informed by the CALO-RE taxonomy of behaviour change techniques [44]. An additional file shows
the mapping of intervention content to theoretical constructs (see Additional file 2).