The pharmacological management of hypertension in pregnancy

The management of pregnancy-induced hypertension (PIH) and preeclampsia using antihypertensive drug therapy remains contentious. Conflicts arise due to differences in diagnostic criteria and varying attitudes regarding the value of treating hypertension, which is only one aspect of this systemic disorder. The following review assesses the role of individual agents and their effects upon both maternal and foetal/neonatal wellbeing.

Human clinical trials of each of the main antihypertensive drugs used in the management of PIH/preeclampsia are reviewed. The value of randomized, placebo-controlled trials and long-term paediatric follow up is stressed.

A number of agents have a favourable benefit-risk profile for use in women with PIH/preeclampsia; these include alpha-methyldopa, beta-blockers, hydralazine, prazosin, calcium channel antagonists and ketanserin. Diazoxide and sodium nitroprusside may also be used for acute severe hypertension. Angiotensin converting enzyme inhibitors are contra-indicated. Low-dose aspirin is presently being investigated in multicentre trials and may play a major role in the prevention of preeclampsia.

Decisions regarding the need for antihypertensive treatment during pregnancy and the selection of a specific antihypertensive agent should be based upon an assessment of the relative benefits and risks for the individual patient. In future studies, the effects of antihypertensive agents upon the underlying pathophysiological processes involved in PIH/preeclampsia may guide therapeutic decision making.