Blood pressure is the pressure in the blood vessels in your body. It is the force with which the blood moves through the blood vessels. Doctors and nurses measure blood pressure by putting a cuff around your upper arm. Then they listen to your blood flow with a stethoscope. High blood pressure (also called hypertension) occurs when your blood moves through your blood vessels at a higher pressure than normal.
There are three types of high blood pressure in pregnant women:
PIH can prevent the placenta (which gives oxygen and food to your baby) from getting enough blood. If the placenta doesn't get enough blood, your baby gets less oxygen and food. This can cause low birth weight and other problems for the baby.
Most women who have PIH still deliver healthy babies. A few develop a condition called eclampsia (PIH with seizures), which is very serious for the mother and baby, or other serious problems. Fortunately, PIH is usually detected early in women who get regular prenatal care, and most problems can be prevented.
If you have any of the following symptoms of PIH, call your doctor right away:
Not necessarily. If your doctor sees that your blood pressure is high, he or she will watch you closely for changes that could mean you have PIH. In addition to high blood pressure, women who have PIH also have excessive swelling. They may also have protein in their urine. Many women who have high blood pressure during pregnancy don't have protein in their urine or extreme swelling, and don't get PIH.
Swelling alone doesn't necessarily mean you have PIH. Some swelling is normal during pregnancy. For example, your rings or shoes might become too tight. Swelling is more serious if it doesn't go away after resting, if it's very obvious in your face and hands or if it's a rapid weight gain of more than 5 pounds in a week.
PIH is more common during a woman's first pregnancy and in women whose mothers or sisters had PIH. The risk of PIH is higher in women carrying multiple babies, in teenage mothers and in women older than 40 years of age. Other women at risk include those who had high blood pressure or kidney disease before they became pregnant. The cause of PIH isn't known.
No one test diagnoses PIH. Your blood pressure will be checked during each doctor's visit. A big rise in your blood pressure can be an early sign that you might have PIH. A urine test can tell if there is protein in your urine. Your doctor may order certain blood tests, which may show if you have PIH. If you have signs of PIH, your doctor may want to see you at least once a week and possibly every day.
The treatment will depend on the type of high blood pressure:
One way to control high blood pressure when you're not pregnant is to cut the amount of salt you eat. This is not a good idea if you have high blood pressure during pregnancy. Your body needs salt to keep up the flow of fluid in your body, so you need a normal intake of salt. Your doctor will tell you how much salt to eat each day and how much water you should drink each day.
This is up to your doctor and you. A Cesarean section (an operation to deliver the baby) is more likely if your health or your baby's health is in danger. If things aren't this serious, your doctor may use medicine (such as oxytocin) to start your labor, and you can deliver your baby through a vaginal delivery.
High blood pressure during pregnancy can cause the following problems for you and your baby:
NHBPEP Report on High Blood Pressure in Pregnancy: A Summary for Family Physicians by MA Zamorski, M.D., M.H.S.A. and LA Green, M.D., M.P.H. (American Family Physician July 15, 2001, http://www.aafp.org/afp/20010715/263.html)
Written by familydoctor.org editorial staff