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How do health care providers diagnose preeclampsia, eclampsia, and HELLP syndrome?

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A health care provider should check a pregnant woman's blood pressure and urine during each prenatal visit. If the blood pressure reading is considered high (140/90 or higher), especially after the 20th week of pregnancy, the health care provider will likely perform more extensive lab tests to look for extra protein in the urine (called proteinuria) as well as other abnormalities.

Gestational hypertension is diagnosed if the woman has high blood pressure but no protein in the urine. Gestational hypertension occurs when women with normal blood pressure levels before pregnancy develop high blood pressure after 20 weeks of pregnancy. Gestational hypertension can develop into preeclampsia.1

Mild preeclampsia is diagnosed when a pregnant woman has:

  • Systolic blood pressure (top number) of 140 mmHg or higher or diastolic blood pressure (bottom number) of 90 mmHg or higher
  • Urine with 0.3 or more grams of protein in a 24-hour specimen (a collection of every drop of urine within 24 hours)

Severe preeclampsia occurs when a pregnant woman has:

  • Systolic blood pressure of 160 mmHg or higher or diastolic blood pressure of 110 mmHg or higher on two occasions at least 6 hours apart
  • Urine with 5 or more grams of protein in a 24-hour specimen or 3 or more grams of protein on 2 random urine samples collected at least 4 hours apart
  • Test results suggesting blood or liver damage—for example, blood tests that reveal low numbers of red blood cells, low numbers of platelets, or high liver enzymes
  • Symptoms that include severe weight gain, difficulty breathing, or fluid buildup2

Eclampsia occurs when women with preeclampsia develop seizures.

A health care provider may do other tests to assess the health of the mother and fetus, including:

  • Blood tests to see how well the mother's liver and kidneys are working
  • Blood tests to check blood platelet levels to see how well the mother's blood is clotting
  • Blood tests to count the total number of red blood cells in the mother's blood
  • A maternal weight check
  • An ultrasound to assess the fetus's size
  • A check of the fetus's heart rate
  • A physical exam to look for swelling in the mother's face, hands, or legs as well as abdominal tenderness or an enlarged liver

HELLP syndrome  is diagnosed when laboratory tests show hemolysis, elevated liver enzymes, and low platelets. There also may or may not be extra protein in the urine.3


  1. Saudan, P., Brown, M. A., Buddle, M. L., Jones, M. (1998). Does gestational hypertension become pre-eclampsia? British Journal of Obstetrics and Gynaecology 105, 1177–1184. [top]
  2. Sibai, B. M. (2012). Hypertension. In S. G. Gabbe, J. R. Niebyl, J. L. Simpson, & M. B. Landon (Eds.), Obstetrics: Normal and problem pregnancies (6th ed.). Philadelphia: Saunders. [top]
  3. Haram, K., Svendsen, E., & Abildgaard, U. (2009). The HELLP syndrome: Clinical issues and management. A Review. BMC Pregnancy and Childbirth, 9. doi:10.1186/1471-2393-9-8. Retrieved July 11, 2012, from http://www.biomedcentral.com/content/pdf/1471-2393-9-8.pdf External Web Site Policy (PDF - 465 KB) [top]

Last Updated Date: 11/30/2012
Last Reviewed Date: 11/30/2012
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