Antenatal dietary education and supplementation to increase energy and protein intake.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized trials
PubMed 26031211 · doi:10.1002/14651858.CD000032.pub3
What was done
A Cochrane systematic review and meta-analysis evaluated randomized controlled trials assessing antenatal dietary education or supplementation (balanced energy and protein, high-protein, or isocaloric protein) aimed at increasing maternal energy and protein intake. Risk of bias and GRADE certainty were evaluated across 17 included trials involving 9,030 women.
What was found
Nutritional education (5 trials, 1,090 women) reduced preterm birth (RR 0.46, 95% CI 0.21 to 0.98; 2 trials, 449 women) and low birthweight (RR 0.04, 95% CI 0.01 to 0.14; 1 trial, 300 women), increased head circumference (MD 0.99 cm, 95% CI 0.43 to 1.55; 1 trial, 389 women), and increased birthweight among undernourished women (MD 489.76 g, 95% CI 427.93 to 551.59; 2 trials, 320 women) and daily protein intake (MD 6.99 g/day, 95% CI 3.02 to 10.97; 3 trials, 632 women), but did not significantly increase birthweight in adequately nourished women or alter gestational weight gain, neonatal death, or stillbirth. Balanced energy and protein supplementation (12 trials, 6,705 women) significantly reduced stillbirth (RR 0.60, 95% CI 0.39 to 0.94; 5 trials, 3,408 women) and small-for-gestational age (RR 0.79, 95% CI 0.69 to 0.90; 7 trials, 4,408 women), and increased birthweight (MD 40.96 g, 95% CI 4.66 to 77.26; 11 trials, 5,385 women), with no significant effect on preterm birth or neonatal death. High-protein supplementation (1 trial, 505 women) increased the risk of small-for-gestational age (RR 1.58, 95% CI 1.03 to 2.41) with no benefit on birthweight. Isocaloric protein supplementation (2 trials, 184 women) showed no significant effects on birthweight or maternal weight gain.
Why it matters
Balanced energy and protein supplementation during pregnancy provides clear fetal benefits by reducing stillbirths and fetal growth restriction. Conversely, high-protein supplementation provides no benefit and may impair fetal growth.
Limits
The risk of bias was unclear or high in at least one domain across multiple included trials. Evidence certainty was low or very low for many outcomes, including nutritional education and isocaloric protein supplementation, and perinatal mortality data were missing or underreported across several sub-analyses.
Cited by
- supports Across studies in pregnant women, low-protein diets lead to smaller babies.