Hypertension in pregnancy is defined as a diastolic blood pressure of 90 mmHg or more. It complicates 5 to 7 percent of pregnancies and is a major cause of inadequate fetal growth, lack of oxygen supply to fetus, neonatal complications and death, and maternal complications and death. Therefore, pregnancy complicated by hypertension does pose a risk to both the fetus and the mother.

A family history of hypertension, extremes of reproductive age, first pregnancy, multiple gestation, hydatidiform mole (a form of pregnancy tumor), diabetes, kidney disease, and hypertension prior to pregnancy are some of the factors that may contribute to the development of hypertension during pregnancy.

Hypertension can occur in 1 of the 3 forms. It can be present before conception occurs and is commonly known as pre-existing hypertension. It may occur after 20 weeks? gestation and experts name this as gestational hypertension with or without preeclampsia/eclampsia. Or, it can exist as a combination of the two. Preeclampsia/eclampsia is a form of pregnancy disorder that affects blood pressure as well as the brain, kidney, liver and blood.

The control of severe hypertension in pregnancy (that is blood pressure higher than 170/110 mmHg) is essential and should be done immediately. This will prevent maternal death from bleeding in the brain (cerebral hemorrhage) and eclampsia. The need to control mild hypertension in pregnant mothers is less evident, but treatment of mild hypertension has been shown to reduce the subsequent development of severe high blood pressure. Nevertheless, its value in preventing fetal loss or development of eclampsia remains unproven.

Pregnant women with hypertension are usually asked to rest in bed and take antihypertensive medications. Restriction of dietary sodium is generally not advised. In view of the potential risks of medication to the unborn child, many ?old? but ?safe? drugs (such as methyldopa, hydralazine, labetalol, nifedipine) are often used. Some newer antihypertensive medications such as ACE inhibitors and ARBs are not recommended because of the possible ill effects to the fetus.

Occasionally, medical delivery is required to control hypertension or its possible complications. A multi-disciplinary approach combining the expertise of an obstetrician, a physician, a neonatologist and a nurse is usually required for the optimal care of a hypertensive mother with complications.