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. The highest blood pressure
happens when the heart contracts and is pumping the blood. High blood pressure (hypertension)
directly increases the risk of heart attack and stroke. Hypertension is defined in
an adult as:
Systolic pressure of 140 mm Hg or higher. Pressure is at its highest when the heart contracts and is pumping the blood. This
is called systolic pressure.
Diastolic pressure of 90 mm Hg or higher. When the heart is at rest, in-between beats, blood pressure falls. This is called
Chronic hypertension is when a pregnant woman has pre-existing hypertension, or develops
it before the 20th week of pregnancy.
Another form of hypertension in pregnancy is preeclampsia. Preeclampsia is a serious
condition. It causes hypertension and problems with 1 or more organs, such as 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. But 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 baby before and after birth depend on the severity of the disease. The
risks may include:
Managing chronic hypertension during pregnancy
It's important to have prenatal care with careful monitoring of blood pressure. Women
with high blood pressure often need to keep taking their blood pressure medicine.
Your healthcare provider may switch you to a safer medicine while pregnant. A low-dose
of daily aspirin may be advised to help prevent problems.
You may need tests on a regular basis. These are done to check the levels of substances
in blood and urine related to hypertension. You may also need other tests to check
your heart and kidney function. Testing of your baby may begin in the second trimester
and may include:
Ultrasound. Sound waves sent through a transducer are used to measure fetal growth.
Nonstress test. This measures fetal heart rate in response to fetal movement
Biophysical profile. This is a test that combines an ultrasound with the nonstress test.
Doppler flow studies. This is a type of ultrasound that uses sound waves to measure blood flow in babies
with fetal growth restriction (FGR).