What is it?

Sometimes called toxemia, pregnancy induced hypertension (PIH), pre-eclampsia, or gestational hypertension, high blood pressure in pregnancy is a complication that occurs in approximately 8% of pregnant women. Usually it is detected some time after the 20th week of pregnancy and it goes away soon after the baby is born. Sometimes there are no noticeable symptoms. A blood pressure reading above 140/90 is considered high, but any significant rise from the woman’s early pregnancy readings could also be high for her.

Why is it a problem?

Sometimes the PIH is mild, with only a slight elevation of blood pressure and the mother and baby will likely be healthy. When it is more severe, other conditions can develop which can place the mother and baby at risk. It can develop slowly or suddenly.  The mother may have organ damage (eyes, kidneys, liver, brain), swelling of hands and face and even seizures. The baby may not get enough blood, which is rich in oxygen and nutrients, through the placenta and may stop growing.  The baby may also be at risk for premature delivery and related problems. It is important that it is diagnosed early and controlled.

Who gets it?
Doctors do not know why some women get PIH, but the risk seems to be greater in the following groups of women:

• Those with a personal or family history of preeclampsia
• Those who are pregnant for the first time
• Those who are over age 40 or under age 20
• Those who are carrying more than one baby
• Those who have medical conditions such as diabetes, kidney disease, lupus, or rheumatoid arthritis
• Those who are obese
• Those who are African American

The cause of PIH is unclear and still being researched, but some possible causes may include poor blood flow to the uterus, damage to the blood vessels, problem with the immune system, or poor diet.  Other associated factors may include infection (urinary tract infections or gum disease), insufficient vitamin D , or high levels of certain proteins in the blood which interfere with growth of blood vessels

What can I do?

Before pregnancy: 

• Lose weight by diet and exercise
• Maintain normal body weight
• Take blood pressure medications as prescribed
• If you have diabetes, make sure that it is in good control
• Make sure your blood pressure medicine is safe to use during pregnancy

During pregnancy: 

• Go for early and regular prenatal care
• Tell your provider if you have kidney disease or other medical conditions
• Tell your provider right away if you have any of the following warning signs:

  • Sudden weight gain of more than about 1 pound a day
  • Swelling of the face and hands
  • Severe or constant headaches
  • Blurred vision or spots in front of the eyes, loss of vision or other visual changes
  • Pain in the upper right part of the abdomen

Many times PIH can be controlled, but the only real cure is having the baby. Sometimes PIH becomes serious enough to require bed rest or an early delivery.  Your provider will order blood tests to make sure the liver and kidney are still functioning well and that there are enough platelets in your blood for clotting.  You may be asked to save urine for 24 hours to test the kidney function, and your baby may be monitored twice weekly to make sure there is no distress.  Medication is sometimes given in the hospital during labor to prevent seizures or to lower blood pressure. Working with your health care provider (doctor or certified nurse midwife) will help improve your chances of having a healthy baby.

Resources:
MayoClinic.com, “Preeclampsia,” accessed 10/28/10.

American Congress of Obstetricians and Gynecologists Patient Education booklet, “High Blood Pressure During Pregnancy,” , www.acog.org/publications/patient_education/bp034.com, accessed 10/28/10.