Reference
Fair F, Soltani H. A meta-review of systematic reviews of lifestyle interventions for reducing gestational weight gain in women with overweight or obesity. Obes Rev. 2021 May;22(5):e13199. doi: 10.1111/obr.13199
Abstract
The results of a recent meta-review produced a systematic overview of current reviews regarding the effectiveness of lifestyle interventions on GWG (gestational weight gain) in women with overweight or obesity.
Background
Limiting GWG in women with overweight or obesity is viewed as important due to the multiple risks associated with excessive weight gain. As lifestyle interventions appeared to decrease gestational weight gain, many guidelines recommend limiting GWG through healthy eating and physical activity. Given the rising number of systematic reviews in this area, and in the face of contradictory evidence, a systematic overview of all evidence is deemed necessary. The purpose of such an overview is to evaluate the most appropriate lifestyle interventions during pregnancy, especially in order to help women with overweight or obesity avoid excessive GWG.
Characteristics of the study
This overview involved searching eight electronic databases. The research was limited to studies with RCTs, in order to minimize study design heterogeneity and ensure comparability. The review focused exclusively on women with overweight and/or obesity (or reported as a subgroup) and reported the outcome of GWG. Lifestyle interventions included dietary interventions, physical activity, or a combination of both. The quality of the included reviews was assessed by two independent researchers. A narrative data analysis was carried out, with subgroup and sensitivity analyses for each type of intervention. A total of 15 systematic reviews were included within the meta-review.
Results
Lifestyle interventions appear to have a small effect on reducing GWG in women with overweight or obesity. A reduction in gestational weight gain of between 0.3 and 2.4 kg was noted with lifestyle interventions compared with standard care. Due to the methodological and statistical heterogeneity of the studies investigated in most of the included reviews, it was not possible to identify the most effective interventions within this group of women (diet alone, physical activity alone, or combined interventions). Due to the small nature of the reduction in GWG produced by lifestyle interventions in women with overweight or obesity, current evidence does not indicate a clear benefit for maternal and infant health outcomes. The authors concluded that determining which behavior change techniques are effective, as well as the required frequency of an intervention, requires further investigation within the subpopulation of pregnant women with overweight or obesity.
Limits of the study
One limitation of this review is the diverse nature of the included lifestyle interventions, which prevented an understanding of the effective components of interventions. Within the studies, and therefore within the systematic reviews, there is also inconsistency relating to the definition of end points for GWG. This overview is further limited by the limitations of the included reviews, which include the quality of their searches, extraction, and reporting. These biases led to the inclusion of apparently ineligible trials within systematic reviews. Finally, several errors in data extraction within included reviews were noted, such as extracting standard error rather than standard deviation. The authors felt that going back to the original study results within this overview, to correct and highlight the areas of inconsistency, has partly mitigated these limitations.
What is new?
The identification of effective components of lifestyle interventions that promote dietary improvements during pregnancy and optimize gestational weight gain has been identified as a key research priority by the Health in Preconception, Pregnancy, and Postpartum Global Alliance. However, given the small amount of reduced GWG produced by lifestyle interventions undertaken during pregnancy in women with overweight or obesity, current evidence does not show a clear benefit in maternal and infant outcomes.
Perspectives
The findings of Fair and Soltani suggest the need for further trials to identify the most effective components of lifestyle interventions, as well as their application procedures. The impact of specific nutrients in pregnancy also needs further exploration in both pregnant women as a whole and within the subgroup of women with overweight or obesity. To reduce some heterogeneity between studies, a universal definition for the measurement of GWG would be beneficial. Consideration should also be given to exploring lifestyle interventions in the prenatal period, given the current lack of proven benefits in maternal and infant outcomes from lifestyle interventions during pregnancy. Edited by Elisabetta Bravini and Carmela Rinaldi
