Chronic hypertension in pregnancy.

Chronic hypertension in pregnancy is associated with increased rates of adverse maternal and fetal outcomes both acute and long term. These adverse outcomes are particularly seen in women with uncontrolled severe hypertension, in those with target organ damage, and in those who are noncompliant with prenatal visits. In addition, adverse outcomes are substantially increased in women who develop superimposed preeclampsia or abruptio placentae. Women with chronic hypertension should be evaluated either before conception or at time of first prenatal visit. Depending on this evaluation, they can be divided into categories of either "high risk" or "low risk" chronic hypertension. High-risk women should receive aggressive antihypertensive therapy and frequent evaluations of maternal and fetal well-being, and doctors should recommend lifestyle changes. In addition, these women are at increased risk for postpartum complications such as pulmonary edema, renal failure, and hypertensive encephalopathy for which they should receive aggressive control of blood pressure as well as close monitoring. In women with low-risk (essential uncomplicated) chronic hypertension, there is uncertainty regarding the benefits or risks of antihypertensive therapy. In my experience, the majority of these women will have good pregnancy outcomes without the use of antihypertensive medications. Antihypertensive agents are recommended and are widely used in these women despite absent evidence of either benefits or harm from this therapy. These recommendations are based on dogma and consensus rather than on scientific evidence. There is an urgent need to conduct randomized trials in women with mild chronic hypertension in pregnancy.