title: Balanced protein/energy supplementation in pregnancy.
abstract: BACKGROUND
  Observational and non-randomized studies have suggested that energy/protein supplementation in pregnant women increases gestational weight gain and fetal growth.
  
  
  OBJECTIVE
  The objective of this review was to assess the effects of a balanced protein/energy supplement for pregnant women on gestational weight gain and on the outcome of pregnancy.
  
  
  METHODS
  The Cochrane Pregnancy and Childbirth Group trials register was searched. Date of last search: January 2000.
  
  
  METHODS
  Acceptably controlled trials of energy/protein supplementation for pregnant women in which the protein content of the supplement was 'balanced' (protein content less than 25% of total energy content).
  
  
  METHODS
  One reviewer assessed trial quality and extracted data. Study authors were contacted for additional information.
  
  
  RESULTS
  Thirteen trials were included. They were of variable quality. Balanced protein/energy supplementation was associated with modest increases in maternal weight gain (weighted mean difference 17 grams per week, 95% confidence interval 5-29 grams per week) and fetal growth (birth weight increase, weighted mean difference 25 grams, 95% confidence interval 4-55 grams). The reduction in risk of small for gestational birth was substantial, however (odds ratio 0. 64, 95% confidence interval 0.53-0.78). These effects did not appear to be greater in undernourished women, nor did they seem to confer long term benefits to the child. No significant effects were detected on preterm birth, but significant reductions in stillbirth and neonatal death (based on only 3 trials) appear important.
  
  
  CONCLUSIONS
  Balanced energy/protein supplementation improves fetal growth and may reduce the risk of fetal and neonatal death. The evidence is insufficient to evaluate whether there are other potential benefits to pregnant women or their infants.
authors.affiliation: Faculty of Medicine, McGill University, 1020 Pine Avenue West, Montreal, Quebec, CANADA, H3A 1A2. mikek@epid.lan.mcgill.ca
authors.forename: M S
authors.initials: MS
authors.lastname: Kramer
mesh_terms: D019587:Dietary Supplements; D005314:Embryonic and Fetal Development; D002149:Energy Intake; D005260:Female; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D015430:Weight Gain