Hypertension in pregnancy

Hypertension in pregnancy

About 5% to 10% of all pregnancies are complicated by hypertension. Hypertension associated with pregnancy is a heterogeneous complex of various pathophysiological conditions. Chronic hypertension is elevated blood pressure (>140/90mmHg) before 20 weeks' gestation that persists beyond 6 weeks after birth of the baby. Essential hypertension accounts for 90% of these cases, while secondary causes, such as parenchymal and vascular renal diseases and endocrine and connective tissue disorders, are responsible for the rest.

Generally, women with mild chronic hypertension (diastolic pressure below 110mmHg) have similar pregnancy outcomes to normal pregnant women.

Pharmacological treatment of hypertension is advised when diastolic pressure exceeds 90mmHg and systolic pressure exceeds 150mmHg. When symptoms of pre-eclampsia are present, treatment can be started at lower pressures

already. The aim of therapy is a preferred diastolic blood pressure of <90mmHg (at least <100mmHg) and a systolic pressure of <150mmHg (at least <160 mmHg). In addtion, symptoms of pre-eclampsia must be followed closely.

Methyldopa is the drug of choice during pregnancy, although the safety and efficacy of calcium channel blockers and β-blockers appear well established. β-adrenergic blocking agents (labetolol, atenolol) are used for various indications during pregnancy. There is also sufficient evidence to conclude that β-blockers have no major teratogenic effects on humans. Concerns about possible perinatal adverse effects have been raised after reports of intrauterine growth retardation, foetal bradycardia, and hypoglycemia associated with their use during gestation were published.

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Methyldopa is a: