Moderate exercise, dieting may reduce risk of C-section, gestational diabetes
A healthy diet and regular exercise during pregnancy can limit gestational weight gain without adverse effects on offspring outcomes, along with reduced risks of caesarean section and gestational diabetes, according to a systematic review and meta-analysis by the i-WIP* Collaborative Group.
“Our findings are important because it is often thought that pregnant women shouldn’t exercise because it may harm the baby. But we show that the babies are not affected by physical activity or dieting,” said senior author Professor Shakila Thangaratinam from Barts Research Centre for Women’s Health at Queen Mary University of London, UK.
Pregnant women who received diet- and physical activity-based interventions gained an average of 0.7 kg less weight than those who did not undergo intervention (control group), and the difference between groups was significant after adjustment for baseline weight and clustering. [BMJ 2017;358:j3119]
Women in the intervention group were also significantly less likely to undergo caesarean section compared with control (odds ratio [OR], 0.91, 95 percent confidence interval [CI], 0.83–0.99).
Evidence of benefit in terms of reduction in gestational diabetes risk was significant in particular among interventions based mainly on physical activity (OR, 0.67, 95 percent CI, 0.44–0.99), although the difference between groups was not statistically significant in the overall individual participant data meta-analysis comparing diet and exercise based interventions with routine care.
The results remained across subgroup analyses based on maternal baseline characteristics such as body mass index (BMI), age, parity, ethnicity, and medical comorbidities.
Also, no significant effect was observed with interventions during pregnancy on offspring outcomes, including stillbirth, small/large for gestational age foetus, and admission to a neonatal intensive care unit.
“Mothers should be reassured about the safety of the interventions, particularly on physical activity and structured exercise in pregnancy, by highlighting the benefits and lack of harm. This may improve engagement and compliance with the intervention,” advised Thangaratinam and co-authors.
“This should be part of routine advice in pregnancy, given by practitioners as well as midwives. Now that we’re able to link the advice to why it’s beneficial for mothers-to-be, we hope mothers are more likely to adopt these lifestyle changes,” Thangaratinam added.
The meta-analysis included 36 trials comprising individual participant data of 12,526 pregnant women who were randomized to interventions based on diet and/or physical activity of moderate intensity or routine care.
“Often with interventions like these, certain groups benefit more than others, but we’ve shown that diet and physical activity have a beneficial effect across all groups, irrespective of your BMI, age or ethnicity; so these interventions have the potential to benefit a huge number of people,” said Thangaratinam.
The long-term benefits of these interventions on mother and child need to be confirmed in large randomized trials to enable detailed recommendations to be made, according to the researchers.