Chronic Hypertension and Pregnancy
What is chronic hypertension?
Blood pressure is the force of the blood pushing against the artery walls. Each time
the heart beats, it is pumping blood into these arteries. This results in the highest
blood pressure when the heart contracts and is pumping the blood. High blood pressure,
or hypertension, directly increases the risk of heart attack and stroke. Hypertension
is defined in an adult as a blood pressure:
Greater than or equal to 140 mm Hg systolic pressure (Pressure is at its greatest
when the heart contracts and is pumping the blood. This is called systolic pressure.)
Greater than or equal to 90 mm Hg diastolic pressure (When the heart is at rest, in-between
beats, blood pressure falls. This is called diastolic pressure.)
When a woman has pre-existing hypertension or develops hypertension before the 20th
week of pregnancy, this is called chronic hypertension.
Other forms of hypertension in pregnancy include preeclampsia. Preeclampsia is a serious
condition with hypertension and problems with one or more organs (for example the
kidneys). Chronic hypertension increases the risk for preeclampsia.
How does pregnancy affect chronic hypertension?
Most risks are not increased for most women with mild chronic hypertension if there
are no other complications. However, risks are much greater for mother and baby if
hypertension is severe. This is also true if there are other conditions such as diabetes
or if preeclampsia develops along with chronic hypertension.
Risks of severe chronic hypertension in pregnancy may include:
Risks to the fetus and newborn depend on the severity of the disease and may include:
Management of chronic hypertension during pregnancy
Prenatal care with careful monitoring of blood pressure are important. Women with
high blood pressure often need to continue taking their antihypertensive medicine.
Your healthcare provider may switch you to a safer antihypertensive medicine while
pregnant. A low-dose of daily aspirin may be recommended to help prevent complications.
Lab tests may be done on a regular basis to check the levels of various blood and
urine substances related to hypertension. Other tests to monitor heart and kidney
function may also be done. Fetal testing may begin in the second trimester and may
Ultrasound. Sound waves sent through a transducer are used to measure fetal growth.
Nonstress test. Measures fetal heart rate in response to fetal movement
Biophysical profile. A test that combines an ultrasound with the nonstress test
Doppler flow studies. A type of ultrasound that uses sound waves to measure blood flow in babies with fetal