Nutritional Manipulation for the Primary Prevention of Gestational Diabetes Mellitus: A Meta-Analysis of Randomised Studies

PLoS ONE
Q1
Feb 2015
Citations:122
Influential Citations:4
Systematic Reviews / Meta-Analyses
90
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Methods
Systematic review and meta-analysis of randomized controlled trials evaluating nutritional manipulation in pregnancy to prevent GDM. Included 20 RCTs (6,444 pregnant women). Participants encompassed both high-risk (e.g., obesity, prior GDM, advanced maternal age) and low-risk pregnancies, across BMI categories. Interventions included diet-based, mixed diet-and-lifestyle, and nutritional supplements; comparator: standard antenatal care.
Intervention
myo-inositol: 2 g twice daily plus 200 µg folic acid; started at 12-13 weeks gestation. Probiotics: Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12, 10^10 CFU daily; taken daily in addition to intensive dietary counselling.
Results
Diet-based interventions reduced GDM risk by 33% (RR 0.67; 95% CI 0.39-1.15; I2 = 52%), but not statistically significant. Mixed diet-and-lifestyle approaches had no effect (RR 0.95; 95% CI 0.89-1.22; I2 = 23%). Nutritional supplements with diet reduced GDM risk: probiotics (RR 0.40; 95% CI 0.20-0.78) and myo-inositol (RR 0.40; 95% CI 0.16-0.99). A BMI interaction showed greater benefit of diet-based interventions in obese/overweight women (RR 0.40; 95% CI 0.18-0.86). Conclusion: Diet-based or mixed approaches do not consistently reduce GDM; nutritional supplements show potential and warrant larger, multicenter trials to define effective regimens and target populations.
Limitations
Differences in inclusion criteria and intervention components; variation in duration, intensity, and frequency; non-standardized GDM definitions; multi-component interventions complicating attribution of effects to a single component; Hawthorne effect due to accessible interventions and lack of blinding; variable adherence; not all trials designated GDM as a primary outcome; some risk of bias in blinding/outcome assessment.

Abstract

Introduction The rise in gestational diabetes (GDM), defined as first onset or diagnosis of diabetes in pregnancy, is a global problem. GDM is often associated with unhealthy diet and is a major contributor to adverse outcomes maternal and fetal outc...