Exams and Tests

High blood pressure (hypertension) and preeclampsia are typically detected during regular prenatal checkups. Because these conditions can get worse rapidly and can be life-threatening to you and your fetus, it's important that you have regular checkups during your pregnancy.

Prepregnancy

A prepregnancy blood pressure reading is used to:

• Screen for chronic high blood pressure (hypertension). It's important to know whether you have chronic high blood pressure before becoming pregnant, because it increases your risk of developing preeclampsia.
• Provide a baseline measurement that can be compared with later readings during pregnancy.

Routine prenatal tests

Certain tests are given at each prenatal visit to monitor for high blood pressure and preeclampsia. These include a:

• Blood pressure reading. (For more information, see considerations about blood pressure readings during pregnancy.)
• Urine test for excess protein in the urine (proteinuria), a sign of preeclamptic kidney damage.
• Weight measurement. (Rapid weight gain can be an indicator of preeclamptic fluid retention.)

Tests for pregnant women considered high-risk for preeclampsia

Other tests may also be used to monitor for signs of preeclampsia, including:

• Blood tests to check for blood abnormalities (as in HELLP syndrome) and for signs of kidney damage. (Elevated uric acid in the blood is often the earliest sign of preeclampsia.)
• Creatinine clearance test, which requires both a blood sample and a 24-hour urine collection, to assess kidney function.
• 24-hour urine collection test to assess protein in the urine.

Tests for women with preeclampsia

If results from one or more of the above tests suggest that you have preeclampsia, you and your fetus will be closely monitored throughout the remainder of your pregnancy. The type and frequency of testing depend on the severity of the preeclampsia and the time remaining until your pregnancy reaches full term (37 to 42 completed weeks). Testing is more frequent and extensive when preeclampsia is severe and the pregnancy is far from full-term (less than 36 weeks).

Tests that may be given to assess your health if you have preeclampsia include:

• A physical exam for signs and symptoms of preeclampsia that is getting worse.
• Blood tests to check for blood abnormalities and kidney damage.
• A creatinine clearance test, which requires both blood and urine samples, to assess kidney function.

Tests for women with eclampsia

If you have a seizure (eclampsia), one or more of the following tests may be done after delivery to assess your brain function and condition:

• A computed tomography (CT) scan uses X-rays to produce detailed pictures of structures inside the body.
• Magnetic resonance imaging (MRI) uses a magnetic field and pulses of radio wave energy to provide pictures of organs and structures inside the body.
• An electroencephalogram (EEG) measures the brain's electrical activity using sensors attached to your head and connected by wires to a computer.

Tests for the fetus

If you develop high blood pressure, preeclampsia, or both, your fetus's health also will be closely monitored. The more severe your condition, the more frequent the fetal testing, ranging from once a week to daily.

Tests commonly used to monitor fetal health include:

• Electronic fetal heart monitoring (including nonstress tests), which records the fetal heart rate and the change in heart rate with fetal movement.
• Fetal ultrasound, which uses reflected sound waves to produce a computerized picture of the fetus, placenta, and uterus to check:
  • Fetal well-being and growth.
  • The condition of the placenta and the possibility of placenta abruptio.
  • The amount of amniotic fluid surrounding the fetus.
• Doppler ultrasound to check how well the placenta is working.

Less commonly, amniocentesis is used to check fetal well-being if preterm delivery is being considered as a treatment option. For this procedure, a needle is inserted into your abdomen to collect amniotic fluid from inside the uterus. The fluid is then checked for chemical signs that the fetus's lungs are mature.

Early Detection

Throughout your pregnancy, prenatal visits will include routine blood pressure measurements and urine tests to screen for preeclampsia.