Hypertension and Preeclampsia

High blood pressure, or hypertension, occurs when there is a consistently higher-than-normal pressure or force of blood against the walls of your arteries. It is normal for a pregnant woman's blood pressure to drop during her first and second trimesters. By the third trimester, however, blood pressure usually returns to normal levels. However, in about 8 to 10 percent of pregnant women, instead of returning to normal, blood pressure begins to increase to abnormally high levels in the second or third trimester. This condition is known as pregnancy-induced hypertension. Women who enter pregnancy with high blood pressure are said to have chronic high blood pressure.

Mild hypertension during pregnancy is not necessarily dangerous by itself, but it can be a sign of a more serious condition called preeclampsia. High blood pressure puts a woman at higher risk for preeclampsia.

Preeclampsia, which is also sometimes called toxemia, is a disorder that only occurs during pregnancy and can also occur during the period right after delivery. It can greatly affect both the mother and unborn baby. Preeclampsia occurs in about 5 to 8 percent of all pregnancies, and very severe cases of preeclampsia can be life threatening. Typically, this condition develops after the twentieth week of pregnancy, in the late second trimester and into the third trimester, although for some it can develop earlier. High blood pressure that develops before the twentieth week is usually a sign of chronic high blood pressure or pregnancy-induced hypertension, but it can also be an early sign of preeclampsia.

Untreated, preeclampsia can cause high blood pressure, problems with blood supply to the placenta and fetus, problems to the liver, kidney, and brain function of the mother as well as the risk of stroke, seizures, and fluid on the lungs. Because the condition affects the blood flow to the placenta and fetus, the baby has a harder time getting the oxygen and nourishment it needs. These babies are often smaller in size and tend to be born prematurely. Women who develop severe preeclampsia can develop life-threatening seizures called eclampsia.

Both chronic high blood pressure and preeclampsia can develop gradually or suddenly and can be mild or severe. If you develop high blood pressure during your pregnancy, you will be monitored closely for signs of preeclampsia throughout your pregnancy.


There is no single test that can diagnose preeclampsia. Your blood pressure is checked at each and every doctor's visit, which makes regular prenatal care even more essential for all pregnant women. A sudden rise in your blood pressure can be an early sign of preeclampsia. A urine test is also used to check for protein in the urine, which can be another warning sign.

High blood pressure does not necessarily mean you have preeclampsia. In addition to high blood pressure, women with preeclampsia tend to have excessive swelling or edema in the hands and face as well as protein in the urine. Many women who experience high blood pressure during pregnancy without these other symptoms don't have preeclampsia.


The causes of high blood pressure and/or preeclampsia are not actually known. Preeclampsia seems to have a possible genetic link because women with a family history of the condition have a higher risk than those who do not. Preeclampsia is more common in first pregnancies as well. The risk of preeclampsia is much higher in women with any of the following conditions or characteristics:

  • Carrying more than one baby

  • Teenage mother

  • History of preeclampsia

  • Obesity

  • Polycystic ovarian syndrome

  • Over age forty

Other factors that put women at a higher risk include high blood pressure, diabetes, an autoimmune disease such as lupus, or a kidney disorder before pregnancy.

Signs and Symptoms

The signs and symptoms of pregnancy-induced hypertension and pre-eclampsia can be classified into three categories: mild, moderate, and severe. The signs and symptoms of high blood pressure and preeclampsia are often silent if the condition is mild. Suspicions usually surface unexpectedly during routine blood pressure checks and urine tests. Moderate preeclampsia can bring with it signs of high blood pressure, protein in the urine, rapid weight gain (more than 1 pound a day), problems with blood clotting, and excessive swelling of the hands and face. Severe preeclampsia can show signs of brain or certain body organ trouble, such as severe headaches, dizziness, vision problems, breathing problems, abdominal pain, and decreased urination. Very rarely, preeclampsia can progress to a condition called eclampsia that can be life-threatening, especially if the preeclampsia is not treated properly and early enough.

Signs of edema or swelling alone do not necessarily mean that you have preeclampsia. Edema can be a very normal symptom of pregnancy. It is considered more serious when it does not go away after putting your feet up, if it is very obvious in your face and hands, and if it causes a rapid weight gain of more than 5 pounds per week or more than 1 pound per day.


If you are diagnosed with preeclampsia, treatment depends on the severity of your condition, the health of your baby, and the stage of your pregnancy. It is recommend that you lie on your left side as much as possible to help take unnecessary pressure off the blood vessels. This allows for greater blood flow.

If you develop mild preeclampsia close to your due date, and your cervix is showing signs of thinning and dilation, your doctor may want to induce labor. This will help prevent any complications that could develop if the pre-eclampsia were to worsen before your delivery.

If your cervix is not showing signs that it is ready for induction, your doctor will probably monitor you and your baby very closely until the time is right to induce or until labor begins on its own. If you develop preeclampsia before the thirty-seventh week of pregnancy, your doctor will most likely recommend bed rest, either at home or in the hospital, depending on your situation. For some, depending on the severity of the blood pressure, blood pressure medication will be prescribed until the pressure stabilizes or until delivery. With severe preeclampsia, a medication to prevent eclampsia (a very serious condition involving seizures) may also be prescribed.

Even though cutting salt from your diet is usually a good way to help control high blood pressure, it is not a good idea to cut the salt in your diet if you have high blood pressure during pregnancy. It is essential that your body gets a normal intake of salt during pregnancy. If you have questions about salt intake with regard to your blood pressure, ask your doctor and a registered dietitian for advice and information.

In general, if you develop preeclampsia, delivery of your baby is the best way to protect you both from complications. If this isn't possible because it is too early in the pregnancy, steps will be taken to manage the preeclampsia until your baby can be safely delivered and survive outside of the womb.

At this point, early diagnosis through simple blood pressure checks and other routine tests at regular prenatal visits is the best way to detect pregnancy-induced hypertension or preeclampsia. The earlier the condition is detected, the earlier treatment and monitoring can begin and the better chance you and your baby have for a healthy pregnancy and healthy delivery.

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