Drugs for treatment of very high blood pressure during pregnancy.
BACKGROUND
Very high blood pressure during pregnancy poses a serious threat to women and their babies. Antihypertensive drugs lower blood pressure. Their comparative effects on other substantive outcomes, however, is uncertain.


OBJECTIVE
To compare different antihypertensive drugs for very high blood pressure during pregnancy.


METHODS
We searched the Cochrane Pregnancy and Childbirth Group Trials Register (28 February 2006) and CENTRAL (The Cochrane Library 2006, Issue 2).


METHODS
Studies were randomised trials. Participants were women with severe hypertension during pregnancy. Interventions were comparisons of one antihypertensive drug with another.


METHODS
Two review authors independently extracted data.


RESULTS
Twenty-four trials (2949 women) with 12 comparisons were included. Women allocated calcium channel blockers rather than hydralazine were less likely to have persistent high blood (five trials, 263 women; 6% versus 18%; relative risk (RR) 0.33, 95% confidence interval (CI) 0.15 to 0.70). Ketanserin was associated with more persistent high blood pressure than hydralazine (four trials, 200 women; 27% versus 6%; RR 4.79, 95% CI 1.95 to 11.73), but fewer side-effects (three trials, 120 women; RR 0.32, 95% CI 0.19 to 0.53) and a lower risk of HELLP (Haemolysis, Elevated Liver enzymes and Lowered Platelets) syndrome (one trial, 44 women, RR 0.20, 95% CI 0.05 to 0.81). Labetalol was associated with a higher risk of hypotension (one trial 90 women; RR 0.06, 95% CI 0.00 to 0.99) and caesarean section (RR 0.43, 95% CI 0.18 to 1.02) than diazoxide. Data were insufficient for reliable conclusions about other outcomes. The risk of persistent high blood pressure was greater for nimodipine compared to magnesium sulphate (two trials 1683 women; 47% versus 65%; RR 0.84, 95% CI 0.76 to 0.93). Nimodipine was also associated with a higher risk of eclampsia (RR 2.24, 95% CI 1.06 to 4.73) and respiratory difficulties (RR 0.28, 95% CI 0.08 to 0.99), but fewer side-effects (RR 0.68, 95% CI 0.54 to 0.86) and less postpartum haemorrhage (RR 0.41, 95% CI 0.18 to 0.92) than magnesium sulphate. Stillbirths and neonatal deaths were not reported. There are insufficient data for reliable conclusions about the comparative effects of any other drugs.


CONCLUSIONS
Until better evidence is available, the choice of antihypertensive should depend on the clinician's experience and familiarity with a particular drug, and on what is known about adverse effects. Exceptions are diazoxide, ketanserin, nimodipine and magnesium sulphate, which are probably best avoided.
Duley
L
L
University of Oxford, Nuffield Department of Medicine, Room 5609, Level 5, John Radcliffe Hospital, Headington, Oxford, UK OX3 9DU. lelia.duley@ndm.ox.ac.uk
Henderson-Smart
D J
DJ
Meher
S
S
D000959:Antihypertensive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000188:drug therapy*; D011225:Pre-Eclampsia / Q000188:drug therapy; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic
D000959:Antihypertensive Agents