Preeclampsia tests include blood pressure readings, urine tests to look for protein, and other lab tests to check for changes in the blood or liver. Doctors may also perform a physical exam.
Health professionals will measure a person’s blood pressure at each prenatal appointment. They may order lab tests if there are signs or symptoms of potential preeclampsia, such as an increase in blood pressure.
Keep reading to learn more about preeclampsia labs, what the results indicate, and what happens next if a person has this condition.
Elevated blood pressure can be the first sign of preeclampsia.
If a pregnant person gets a high blood pressure reading, especially after the
Doctors typically use the following lab tests to diagnose preeclampsia:
Urine test
Initially, doctors test for protein in the urine using a dipstick screening test.
If the test shows protein is present, the doctor may ask the person to collect all their urine in a jug for
However, it is important to note that the amount of protein does not determine how severe the preeclampsia is, or how severe it may become.
Blood tests
Doctors may perform a complete blood count to look for changes that can indicate preeclampsia. They may also assess:
- creatinine levels
- liver enzyme levels
- uric acid levels
A doctor may refer to these blood tests as a preeclampsia panel, HELLP workup, or pregnancy-induced hypertension labs. HELLP syndrome is a severe form of preeclampsia that damages red blood cells, leading to a type of anemia.
Other blood tests measure the levels of a protein known as placental growth factor (PIGF). Low PIGF levels could be a sign of preeclampsia. However, additional tests will need to confirm a diagnosis.
Other tests
In addition to tests that diagnose preeclampsia, doctors
- the person’s weight
- the size and growth of the fetus, via ultrasound
- the fetal heart rate
- for signs of swelling, abdominal tenderness, or an enlarged liver
The following combinations of test results indicate preeclampsia:
Mild preeclampsia
Doctors diagnose mild preeclampsia when a pregnant person has:
- a systolic blood pressure of
140 millimeters of mercury (mmHg) or higher
or - a diastolic blood pressure of 90 mmHg or higher on at least two occasions 4 hours apart at rest
in combination with any of the following:
- 0.3 grams (g) or more of protein in their urine over 24 hours
- a protein-to-creatinine ratio greater than 0.3
- blood tests showing kidney or liver dysfunction, accompanied by the following symptoms:
- fluid in the lungs
- difficulty breathing
- visual changes
Severe preeclampsia
A person has severe preeclampsia if they have:
- a systolic blood pressure of 160 mmHg or higher
or - a diastolic blood pressure of 110 mmHg or higher on at least two occasions 4 hours apart at rest
and any of the following:
- 5 g or more of protein in their urine over 24 hours
- 3 g or more of protein in two random urine samples from at least 4 hours apart
- blood tests showing kidney or liver damage, accompanied by the following symptoms:
- severe and unexplained stomach pain that does not respond to medication
- fluid in the lungs
- difficulty breathing
- visual changes
Doctors test for preeclampsia when a pregnant person’s blood pressure level is high, particularly if this occurs
If a person has atypical lab results and preeclampsia symptoms, doctors will need to closely monitor them.
Medical professionals will schedule more frequent ultrasounds and tests to assess the health of the fetus. They may also check that blood flow through the umbilical cord and placenta is healthy.
A doctor will determine how to manage preeclampsia based on factors such as:
- how many weeks pregnant the person is
- the person’s age and health
- the health of the fetus
- how severe the signs of preeclampsia are
Some medications may help prolong the pregnancy, including anticonvulsants to prevent seizures and antihypertensive drugs to lower blood pressure.
However, if symptoms develop quickly at the end of a person’s pregnancy or during delivery, they may need to go to hospital to receive continuous fetal monitoring or an induction.
Doctors usually recommend inducing labor if the pregnancy is at
In some cases, though, a person must deliver earlier in order to save their life or that of the fetus.
In rare cases, preeclampsia symptoms may not start until after delivery. This is called postpartum preeclampsia.
Doctors usually diagnose postpartum preeclampsia
Health professionals should check blood pressure after delivery to monitor for this complication. People may also wish to monitor their own blood pressure at home using an at-home device.
Doctors treat postpartum preeclampsia with medications. If the blood pressure remains persistently high after delivery, a person may receive a referral to a specialist who provides regular care for people with chronic hypertension.
If a person is monitoring their blood pressure during pregnancy and notices it increasing, they should contact their doctor right away.
People should also contact a doctor immediately if they develop the following symptoms:
- headache that will not get better
- vision problems, such as seeing flashing lights or spots
- swelling of the feet, hands, or face
- sudden weight gain
- pain just below the ribs or in the shoulder
- nausea and vomiting in the second half of pregnancy
- difficulty breathing
These symptoms can be signs of preeclampsia. The earlier doctors diagnose and monitor preeclampsia, the better the person’s outlook.
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Doctors diagnose preeclampsia using blood pressure readings, urine samples, and kidney and liver function tests. They can also base a diagnosis on a person’s symptoms and physical changes, such as sudden swelling or weight gain.
If a person has preeclampsia, a doctor will need to closely monitor them and the fetus. A doctor may also prescribe medications.
Because preeclampsia usually resolves after birth, doctors will often induce an earlier delivery to prevent preeclampsia from causing permanent damage.
A person who has any signs of preeclampsia or concerns about their lab results should speak with a doctor.