What is gestational hypertension?
There are two main forms of gestational hypertension. Both occur after the 20th week of pregnancy and go away without treatment soon after delivery. Preeclampsia is a potentially serious disorder, which is characterized by high blood pressure and protein in the urine. When high blood pressure is not accompanied by protein in the urine, it is referred to as gestational hypertension. However, gestational hypertension may progress to preeclampsia, so all women who develop high blood pressure in pregnancy are monitored closely.

Preeclampsia also may be accompanied by swelling (edema) of the hands and face and sudden weight gain (5 or more pounds in one week). Other signs of preeclampsia include blurred vision, severe headaches, dizziness and intense stomach pain. A pregnant woman should contact her health care provider right away if she develops any of these symptoms.

Preeclampsia usually occurs after about 30 weeks of pregnancy. Most cases are mild, with blood pressure around 140/90. Women with mild preeclampsia often have no obvious symptoms. If left untreated, though, preeclampsia can cause serious problems.

It’s important to remember that many women who develop preeclampsia or gestational hypertension do so at term (at or beyond 37 weeks of gestation). These women generally have few complications.

What risks do preeclampsia and other forms of hypertension pose for a pregnant woman and her fetus?
All forms of hypertension can constrict the blood vessels in the uterus that supply the fetus with oxygen and nutrients. When this occurs before term, it can slow the fetus’s growth, sometimes resulting in low birthweight. Hypertension also increases the risk of pretermdelivery (before 37 weeks gestation). Premature and low-birthweight babies face an increased risk of health problems during the newborn period and lasting disabilities, such as learning problems and cerebral palsy.

Women with hypertension also have an increased risk of placental abruption,  which is separation of the placenta from the uterine wall before delivery. Severe abruption can cause heavy bleeding and shock, which are dangerous for both mother and baby. The most common symptom of abruption is vaginal bleeding after 20 weeks of pregnancy. A pregnant woman always should report any vaginal bleeding to her health care provider immediately. While all women with high blood pressure during pregnancy face some increased risk of abruption and the other complications discussed above, the risk is greatest in women who have preeclampsia along with chronic high blood pressure.³

Preeclampsia also can quickly progress to a rare but life-threatening condition called eclampsia, causing seizures and sometimes coma. Fortunately, eclampsia is rare in women who receive regular prenatal care. At each prenatal visit, blood pressure is measured and urine is checked for protein, so that preeclampsia can be diagnosed and treated before it can progress to eclampsia.

How is preeclampsia treated?
The only cure for preeclampsia is delivery. However, this is not always best for the baby. So treatment depends upon how severe the problem is and how far along a woman is in her pregnancy. If a woman is at term (37 to 40 weeks), the preeclampsia is mild, and her cervix has begun to thin and dilate (signs that it’s ready for delivery), her health care provider probably will recommend inducing labor. This prevents any potential complications that could develop if the pregnancy continues and the preeclampsia worsens. If her cervix is not yet ready for labor, her provider may recommend medication to help prepare her cervix for induction or continue to monitor her and her baby closely until labor starts on its own.

If a woman develops mild preeclampsia before her 37th week, her provider probably will recommend that she reduce her activities.  In some cases, hospitalization may be recommended, though most women can be treated at home. Her baby’s well-being will be closely monitored with tests such as ultrasound and fetal heart rate monitoring. Blood tests probably will be recommended for the pregnant woman to see if the preeclampsia is progressing and harming her health.

If a woman has severe preeclampsia, she should be hospitalized. Her health care provider will probably recommend inducing labor if she is beyond 33 to 34 weeks gestation.⁴ At this stage of pregnancy, the risk of prematurity is generally outweighed by the risk of progression to eclampsia. Before inducing labor, doctors generally treat women who are at less than 34 weeks gestation with a drug called a corticosteroid that helps speed maturity of the fetal lungs to reduce the risk of prematurity-related problems. A woman who develops severe preeclampsia at less than 32 weeks gestation sometimes can be monitored closely in the hospital, to prolong the pregnancy safely while her baby matures.

Sometimes, a woman’s blood pressure continues to rise despite treatment with blood pressure medications, and her baby must be delivered early to prevent serious health problems in the mother, such as stroke, liver damage and seizures. Babies born early may have difficulties due to prematurity, such as trouble breathing. Most of these infants will do better in an intensive care nursery than if they had stayed in the uterus.

About 10 percent of women with severe preeclampsia also develop a disorder called HELLP (an acronym for Hemolysis, Elevated Liver enzymes, and Low Platelet count) syndrome, which is characterized by blood and liver abnormalities.⁵ Symptoms may include nausea and vomiting, headache, upper abdominal pain and general malaise. Women with HELLP syndrome, which also can develop in the first 48 hours after delivery, are treated with medications to control blood pressure and prevent seizures, and sometimes with blood transfusions. Women who develop HELLP syndrome during pregnancy almost always require early delivery to prevent serious complications.