Effect of intervention on fetal weight
Thirty one randomised trials (5278 newborns) evaluated the effect of the interventions on birth weight.26-28 30-40 42 44-50 52 53 57 59 61-63 65 66 Compared with controls,there was minimal reduction in the birth weight that was not significant (mean difference −50 g, 95% confidence interval −100 to 0 g) for all interventions (table 1⇓, fig 4⇓). There was a trend towards reduction in the risk of large for gestational age babies (defined as birth weight above the 90th centile or 4000 g) (relative risk 0.85, 0.66 to 1.09) with interventions (fig 5⇓.The risk of small for gestational age babies (defined as birth weight below the 10th centile or 2500 g) was not altered (1.00,0.78 to 1.28) with interventions (fig 5⇓).