Interventions designed to limit gestational weight gain: a systematic review of theory and meta-analysis of intervention components (#67)
Limiting gestational weight gain (GWG) to recommended levels is important to optimize health outcomes for both mother and baby, including the prevention of maternal obesity and the development of childhood overweight and obesity. Currently, interventions designed to promote healthy GWG have reported limited effectiveness; addressing psychological factors and identifying useful behaviour change techniques (BCTs) may help improve the effectiveness of such interventions. We extend current research by: (i) using a generalized health psychology perspective to systematically evaluate the theories of behavior change informing GWG interventions, and (ii) meta-analyzing BCTs reported in the interventions to identify areas of greater potential for successful intervention. Interventions designed to limit GWG were searched for using health, nursing, and psychology databases. Papers reporting an underpinning theory were identified and the CALO-RE taxonomy developed by Michie et al. (2011) was used to determine individual BCTs. Nineteen studies were identified for inclusion. Of these 19 studies, 8 were informed by a behavior change theory and 6 of these reported favourable effects on GWG. Overall, studies based on theory were found to be as effective as non-theory-based studies at limiting GWG. An average of 5.5 (range 1-12) BCTs were reported per intervention. In general, more techniques were reported in effective interventions. There was also a trend for interventions with a larger number of techniques to report greater differences in GWG between the intervention and control groups (r(n=20) =.30, p=.10). There were 18 techniques that were not utilized in any intervention. Meta-analysis revealed the following BCTs to be key strategies for promoting healthy GWG in the reviewed studies: provision of information, motivational interviewing, behavioral self-monitoring, and providing rewards contingent on successful behavior. Future research should focus on determining the exact combination of BCTs and which underpinning theories are most useful for limiting GWG to healthy levels.