[Hypertension in pregnancy]

Abstract

The most important task of classification of hypertension in pregnancy is to establish whether hypertension predates pregnancy (so-called pre-existing hypertension) or whether this is pregnancy-induced hypertension (so-called gestational hypertension). Pre-existing hypertension is diagnosed either before pregnancy or within 20 weeks of gestation. Gestational hypertension is characterized by poor perfusion of several organs, and the elevated blood pressure (BP) represents usually only one of the characteristic features. Non-pharmacological treatment of hypertension should be considered in pregnant females with systolic BP 140-150 mm Hg or diastolic BP 90-99 mm Hg. Salt restriction or weight reduction is not recommended. Systolic BP > or = 170 or diastolic BP > or = 110 mm Hg in a pregnant woman should be regarded as an emergency requiring hospitalization. Drug treatment with intravenous labetalol, or oral methyldopa or nifedipine should be considered. The thresholds at which to initiate antihypertensive therapy is systolic BP of 140 mm Hg or diastolic BP of 90 mm Hg in women with gestational hypertension without proteinuria or in those with pre-existing hypertension before 28 weeks' gestation. Drug treatment is to be initiated at the same threshold levels in females with gestational hypertension and proteinuria or those presenting with symptoms at any time during the pregnancy, those with pre-existing hypertension in the presence of associated conditions or organ damage and, also, those with pre-existing hypertension and superimposed gestational hypertension. In other cases, it is recommended to institute antihypertensive medication at systolic BP of 150 mm Hg or diastolic BP of 95 mm Hg. For non-severe hypertension, methyldopa, labetalol, calcium-channel blockers should be considered the drugs of choice. ACE inhibitors and angiotensin II antagonists (AT1-blockers) are contraindicated in pregnancy.