Plasma volume expansion for treatment of pre-eclampsia

Not enough evidence to show the effects of plasma volume expansion for women with pre-eclampsia.

Blood plasma volume increases gradually in women during the second half of pregnancy. The increase is usually greater for women with multiple pregnancies and less for those with small babies. Plasma volume is reduced in women with pre-eclampsia (pregnancy induced complication that includes high blood pressure). It is possible that women with pre-eclampsia might benefit from expanded plasma volume if it were to increase blood circulation for the mother and baby. The review of trials found there was not enough evidence to show the effects of plasma volume expansion for women with pre-eclampsia. More research is needed.

Authors' conclusions: 

There is insufficient evidence for any reliable estimates of the effects of plasma volume expansion for women with pre-eclampsia.

[Note: The 14 citations in the awaiting classification section of the review may alter the conclusions of the review once assessed.]

Read the full abstract...
Background: 

Plasma volume is reduced amongst women with pre-eclampsia. This association has led to the suggestion that expanding the plasma volume might improve maternal and uteroplacental circulation, and so potentially improve outcome for both the woman and her baby.

Objectives: 

The aim of this review was to assess the effects of plasma volume expansion for the treatment of women with pre-eclampsia.

Search strategy: 

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register and the Cochrane Controlled Trials Register Issue 4, 2000 were searched for trials meeting the selection criteria.

We updated the search of the Cochrane Pregnancy and Childbirth Group's Trials Register on 1 October 2009 and added the results to the awaiting classification section.

Selection criteria: 

Randomised trials were included. Quasi-random designs were excluded. Participants were women with hypertension during pregnancy, with or without proteinuria. Women who were postpartum at trial entry were excluded. Interventions were any comparison of plasma volume expansion with no expansion, or of one plasma volume expander with another.

Data collection and analysis: 

Data were extracted independently by two reviewers. Discrepancies were resolved by discussion. There was no blinding of authorship or results.

Main results: 

Three trials involving 61 women were included in this review. All compared a colloid solution with no plasma volume expansion. For every outcome reported, the confidence intervals are very wide and cross the no effect line.