Effect of balanced protein energy supplementation during pregnancy on birth outcomes.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized and quasi-randomized trials
PubMed 21501434 · doi:10.1186/1471-2458-11-S3-S17
What was done
Authors conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and quasi-RCTs identified via PubMed, Cochrane Library, and WHO regional databases. The review examined balanced protein-energy supplementation during pregnancy (protein providing <25% of total energy content) versus control. Studies involving dietary advice alone, high-protein supplements (≥25% energy), isocaloric protein replacement, or low-energy diets were excluded. Primary outcomes were small for gestational age (SGA) birth, mean birth weight, and neonatal mortality.
What was found
Eleven RCTs and quasi-RCTs were included. Balanced protein-energy supplementation significantly reduced the risk of SGA birth by 31% (RR = 0.69, 95% CI 0.56 to 0.85) and increased mean birth weight by 59.89 g (95% CI 33.09 to 86.68 g), with larger effects observed in malnourished women. The reduction in neonatal mortality was not statistically significant (RR = 0.63, 95% CI 0.37 to 1.06).
Why it matters
These findings provide pooled effect estimates for global health planning tools (the Lives Saved Tool) to quantify the impact of maternal nutritional supplementation on intrauterine growth restriction in low-resource settings.
Limits
The review pooled quasi-randomized trials alongside standard RCTs, increasing potential risk of bias. Total participant count, intervention duration, baseline nutrient status metrics, and compliance rates are not reported in the abstract. The effect on neonatal mortality lacked statistical power.
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