Drugs for treatment of very high blood pressure during pregnancy

Abstract

Background: Very high blood pressure during pregnancy poses a serious threat to women and their babies. The use of drugs to lower blood pressure will reduce this risk for the women, and possibly also for the baby.

Objectives: The objective of this review was to compare different antihypertensive drugs used for treatment of severe hypertension during pregnancy.

Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register (April 2002), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2 2002) and MEDLINE (April 2002).

Selection criteria: Studies were randomised trials. Quasi random designs were excluded. Participants were women with severe hypertension during pregnancy. Women postpartum at trial entry were excluded. Interventions were any comparisons of one antihypertensive agent with another.

Data collection and analysis: Data were extracted independently by two reviewers to assess eligibility and describe the trial characteristics, and by one reviewer for the meta-analyses. Discrepancies were resolved by discussion. There was no blinding of authorship or results. Whenever possible, unpublished data were sought from investigators.

Main results: Twenty trials were included (1637 women) and 19 were excluded. There were ten different comparisons. Hydralazine was the most common drug for others to be evaluated against. Diazoxide, given as 75mg bolus injections, appears to be associated with maternal hypotension requiring treatment, and ketanserin is less effective than hydralazine at reducing blood pressure. There is no other clear evidence that any one of the other antihypertensive agents is better than another for women with severe hypertension during pregnancy.

Reviewer's conclusions: Until better evidence is available, the choice of antihypertensive should depend on the experience and familiarity of an individual clinician with a particular drug, and on what is known about adverse maternal and fetal side-effects. Exceptions are diazoxide and ketanserin, which are probably not good choices.