Diet, activity reduce gestational weight gain, improve pregnancy outcomes
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A structured antenatal diet in addition to lifestyle interventions that are based on physical activity may reduce gestational weight gain as well as adverse maternal and neonatal outcomes, researchers reported in JAMA Internal Medicine.
“Many studies showed how important and effective lifestyle support is for women in pregnancy, yet this evidence isn’t being put into practice,” Helena J. Teede, MBBS, PhD, FRACP, FAAHMS, FRANZCOG, executive director of the Monash Partners Academic Health Science Centre in Melbourne, Australia, told Healio.
In a systematic review and meta-analysis, Teede and colleagues searched for studies in MEDLINE, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials and Health Technology Assessment Database published between Feb. 1, 2017, and May 31, 2020. They focused on randomized trials that reported on gestational weight gain (GWG) and maternal and neonatal outcomes.
The researchers integrated the results with a previous systematic review of literature spanning January 1990 to February 2017. The 117 studies included in the meta-analysis involved 34,546 women from five different continents.
“The study sought to integrate all of the previous evidence to demonstrate how significant the benefits are and to indicate which type of lifestyle intervention is most useful. This was designed to inform implementation into practice,” said Teede, who also is professor of women’s health at Monash University and director of the Monash Centre for Health Research and Implementation in Australia.
The researchers categorized interventions as structured diet, structured physical activity, and diet with at least one structured component, or personalized advice on diet components or portion sizes rather than generic advice on a healthy diet. Other interventions were categorized as mixed, predominantly unstructured lifestyle support, written information with weight monitoring or behavioral support alone.
“The health benefits were more significant than expected,” Teede said.
Compared with routine care, overall lifestyle interventions were associated with reduced GWG (–1.15 kg; 95% CI, –1.4 to –0.91).
Reduced GWG also was specifically associated with diet (–2.63 kg; 95% CI, –3.87 to –1.4), diet with physical activity (–1.35 kg; 95% CI, –1.95 to –0.75), physical activity (–1.04 kg; 95% CI, –1.33 to –0.74) and mixed interventions (–0.74 kg; 95% CI, –1.06 to –0.43).
“Whilst apparently not that much when you consider these [totals] as a proportion of total weight gained and recommended, they represent up to a 20% difference in pregnancy,” Teede said, adding that diet intake has more direct influence on weight, as it accounts for 100% of intake. Physical activity, however, is a relatively small proportion of output, the rest being relatively fixed in terms of resting body metabolism, she continued.
Also, the researchers found an association between diet and reduced risks for gestational diabetes (OR = 0.61; 95% CI, 0.45-0.82), preterm delivery (OR = 0.43; 95% CI, 0.22-0.84), large for gestational age neonate (OR = 0.19; 95% CI, 0.08-0.47), neonatal intensive care admission (OR = 0.68; 95% CI, 0.48-0.95) and total adverse maternal (OR = 0.75; 95% CI, 0.61-0.92) and neonatal outcomes (OR = 0.44; 95% CI, 0.26-0.72).
Associations were found between physical activity and reduced GWG as well as with reduced risk for gestational diabetes (OR = 0.6; 95% CI, 0.47-0.75), hypertensive disorders (OR = 0.66; 95% CI, 0.48-0.9), cesarean section (OR = 0.85; 95% CI, 0.75-0.95) and total adverse maternal outcomes (OR = 0.78; 95% CI, 0.71-0.86).
Though improved neonatal outcomes only were associated with dietary interventions, improved maternal outcomes were associated with interventions based on structured diets, physical activity and diet combined with physical activity.
These findings, the researchers concluded, support the implementation of interventions using structured diet and physical activity facilitated by trained professionals in antenatal care programs and policies.
“As yet, uptake is limited, as this needs a change in the way maternity care is funded. However, overall, the health benefits mean that the health system saves money with implementation,” said Teede.
Helena J. Teede, MBBS, PhD, FRACP, FAAHMS, FRANZCOG, can be reached at helena.teede@monash.edu.