Management of hypertension in pregnancy

Hypertension in pregnancy is generally defined as either an absolute BP greater than or equal to 140/90 mm Hg or a rise in systolic BP greater than or equal to 25 mm Hg and/or diastolic BP greater than or equal to 15 mm Hg from pre-conception or 1(st) trimester BP. Hypertension in pregnancy is classified as: a) Chronic - essential or secondary hypertension, b) De novo - pre-eclampsia or gestational hypertension, and c) Pre-eclampsia superimposed on chronic hypertension. Pre-eclampsia is a multisystem disorder in which hypertension is but one sign. The major maternal abnormalities occur in kidneys, liver, brain and coagulation systems. Impaired uteroplacental blood flow causes fetal growth retardation or intrauterine death. There is general agreement that BP greater than or equal to 170/110 mm Hg should be lowered rapidly to protect the mother against risk of stroke or eclampsia. There is dispute concerning the level at which lesser degrees of hypertension should be treated, and lowering BP is treating only one aspect of pre-eclampsia. Delivery remains the definitive management.