Women with mild preeclampsia are unlikely to have any symptoms other than mildly elevated blood pressure and proteinuria. These problems usually disappear soon after delivery. Severe preeclampsia can affect various organ systems in the mother and put her baby at risk for complications, as indicated in Table 1.

Table 1. Preeclampsia-Indications of Severity
AbnormalityMildSevere
Systolic blood pressure

Diastolic blood pressure
< 150 mm Hg

< 100 mmHg
160 mmHg or higher

110 mmHg or higher
HeadacheAbsentPresent
Visual disturbancesAbsentPresent
Upper abdominal pain or nausea and vomitingAbsentPresent
ConvulsionsAbsentPresent (eclampsia)
Renal (kidney) function Reduced
Thrombocytopenia (low platelet count)AbsentPresent
Liver function abnormalitiesAbsentPresent
Fetal growth restrictionAbsentPresent

Distinguishing between mild and severe preeclampsia is important for identifying women who are at greater risk for developing eclampsia. However, at any time, mild preeclampsia can progress rapidly to the severe form (marked by headache, abdominal pain, and other uncomfortable symptoms), which is more likely to cause complications in mother and baby. Also, the earlier in the pregnancy preeclampsia develops, the more likely that complications will occur.

In rare cases, preeclampsia leads to two serious complications: the HELLP syndrome (characterized by a clotting disorder, hemolytic anemia from the rapid destruction of red blood cells, and liver dysfunction), and eclampsia (convulsions, seizures). Both conditions require immediate delivery of the baby and continued treatment after delivery. In some women, eclampsia can occur up to four weeks after delivery.

Blood pressure alone is not a good indicator of a woman's susceptibility to seizures. For example, a woman with a blood pressure reading of 150/90 may develop seizures, while another woman with much higher blood pressure levels may not. Symptoms such as severe headaches, visual changes, and upper abdominal pain are better indicators of the severity of the disease.

Complications In the Mother

Although serious complications are rare, blood pressure disorders, edema, and proteinuria can lead to complications, such as:

  • Low levels of red blood cells ( anemia ) and low blood platelet levels, which leads to impaired blood clotting, can cause problems during and after labor. These findings generally occur in pregnant women who develop HELLP syndrome.
  • Cerebral edema (swelling of the brain), vasoconstriction (narrowing of the vessels), and damage to capillary (small blood vessel) linings may lead to exaggerated reflexes, twitching, convulsions, or hemorrhage (stroke).
  • Edema affecting the retinas of the eyes may lead to visual disturbances, retinal detachment, or, rarely, blindness.
  • Fluid loss across damaged capillary endothelium in the lungs may result in pulmonary edema (fluid accumulation in the lungs), a potentially life-threatening complication.
  • Edema of the liver and/or the loss of blood supply due to the constriction of blood vessels ( ischemia ) may cause liver cell damage and the elevation of liver enzymes. Pain in the epigastrium (right, upper quadrant of the abdomen) is attributed to stretching of Glisson's capsule (the fibrous connective tissue surrounding blood vessels of the liver) by swelling or bleeding.
  • Kidney failure and heart attack.

How Can Preeclampsia Affect the Baby?

The effects of preeclampsia on the placenta (through which the baby is nourished), reduce blood flow, nutrients, and oxygen to the baby. The effects can be significant if severe preeclampsia develops before delivery-the baby may suffer reduced oxygenation, leading to premature delivery and small size. Prematurity and low birth weight are the leading causes of complications and death in newborn babies.

The Need for Ongoing Care

Especially if you are at high risk, you must be able to detect the characteristic signs of preeclampsia-hypertension and proteinuria-as early as possible. So, you should initiate prenatal care as soon as you know you are pregnant, and you should not miss any scheduled appointments.

If you do develop severe preeclampsia or if you have significant pre-existing conditions (such as chronic hypertension or kidney disease), you will likely be treated at a medical center with facilities and personnel accustomed to managing high-risk pregnancies. Because of the possible dangers to your baby, it is important that whatever facility you use has an intensive care nursery. You may also be referred for specialized care.