Three small trials (61 women) have compared a colloid solution with placebo or no infusion. These studies were too small for reliable conclusions, but suggest plasma volume expansion is not beneficial34. Systematic reviews of volume expansion for critically ill non-pregnant people found a higher mortality than either not using any plasma expander or expansion with a crystalloid35,,36. Although none of these studies included pregnant women, it would seem prudent to avoid colloid solutions until data Timing of delivery