Preeclampsia is a common problem during pregnancy. The condition — sometimes referred to as pregnancy-induced hypertension — is defined by high blood pressure and excess protein in the urine after 20 weeks of pregnancy.
Often, preeclampsia causes only modest increases in blood pressure. Left untreated, however, preeclampsia can lead to serious — even fatal — complications for both mother and baby.
The only cure for preeclampsia is delivery of the baby. If preeclampsia develops near the end of your pregnancy, delivery is the obvious solution. If you're diagnosed with preeclampsia earlier in your pregnancy, you and your doctor face the delicate task of prolonging your pregnancy to allow your baby more time to mature, without putting you or your baby at risk of serious complications.
Preeclampsia used to be called toxemia because it was thought to be caused by a toxin in a pregnant woman's bloodstream. Although this theory has been debunked, researchers have yet to determine what causes preeclampsia. Possible causes may include :
- Insufficient blood flow to the uterus
- Damage to the blood vessels
- A problem with the immune system
- Poor diet
Risk Factor :
Preeclampsia develops only during pregnancy. Risk factors include:
- History of preeclampsia. A personal or family history of preeclampsia increases your risk of developing the condition.
- First pregnancy. The risk of developing preeclampsia is highest during your first pregnancy or your first pregnancy with a new partner.
- Age. The risk of preeclampsia is higher for pregnant women who are older than age 35.
- Obesity. The risk of preeclampsia is higher if you're obese.
- Multiple pregnancy. Preeclampsia is more common in women who are carrying twins, triplets or other multiples.
- Gestational diabetes. Women who develop gestational diabetes have a higher risk of developing preeclampsia as the pregnancy progresses.
- History of certain conditions. Having certain conditions before you become pregnant — such as chronic high blood pressure, diabetes, kidney disease or lupus — increases the risk of preeclampsia.
In a 2006 study, pregnant women who had high levels of two specific proteins in their blood were found to be more likely to develop preeclampsia than were other women. These proteins interfere with the growth and function of blood vessels — lending evidence to the theory that preeclampsia is caused by abnormalities in the blood vessels feeding the placenta. Although more research is needed, the discovery suggests that a blood test may one day serve as an effective screening tool for preeclampsia.
When to seek medical advice :
Headaches, nausea, and aches and pains are common pregnancy complaints. It's difficult to know when new symptoms are simply part of being pregnant and when they may indicate a serious problem — especially if it's your first pregnancy. If you're concerned about your symptoms, contact your doctor.
Contact your doctor right away if you have severe headaches, blurred vision or severe pain in your abdomen.
The signs of preeclampsia are elevated blood pressure (hypertension) and the presence of excess protein in your urine (proteinuria) after 20 weeks of pregnancy. The excess protein is related to problems with your kidneys. Your doctor may identify these signs of preeclampsia at one of your regular prenatal visits.
Other signs and symptoms of preeclampsia — which can develop gradually or strike suddenly, often in the last few weeks of pregnancy — may include :
- Severe headaches
- Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
- Upper abdominal pain, usually under the ribs on the right side
- Nausea or vomiting
- Decreased urine output
- Sudden weight gain, typically more than 2 pounds a week
Swelling (edema), particularly in the face and hands, often accompanies preeclampsia as well. Swelling isn't considered a reliable sign of preeclampsia, however, because it also occurs in many normal pregnancies.
Other high blood pressure disorders during pregnancy
Preeclampsia is classified as one of four high blood pressure disorders that can occur during pregnancy. The other three are :
- Gestational hypertension. Women with gestational hypertension have high blood pressure, but no excess protein in their urine. Some women with gestational hypertension eventually develop preeclampsia.
- Chronic hypertension. Chronic hypertension is high blood pressure that appears before 20 weeks of pregnancy or lasts more than 12 weeks after delivery. Often, chronic hypertension was present — but not detected — before pregnancy.
- Preeclampsia superimposed on chronic hypertension. This term describes women who have chronic high blood pressure before pregnancy and then develop worsening high blood pressure and protein in the urine during pregnancy.
You'll be diagnosed with preeclampsia if you have high blood pressure and protein in your urine after 20 weeks of pregnancy. Preeclampsia usually shows up unexpectedly during a routine prenatal blood pressure check and urine test. That's why it's essential to seek regular prenatal care throughout your pregnancy.
During pregnancy, a blood pressure reading lower than 130/85 millimeters of mercury (mm Hg) is normal. A blood pressure reading of 140/90 mm Hg or higher is considered above normal. However, a single high blood pressure reading doesn't mean you have preeclampsia. If you have one reading in the abnormal range — or a reading that's substantially higher than your usual blood pressure — your doctor will closely observe your numbers. You may also be asked to come in for additional blood pressure readings and urinary protein measurements.
If you're diagnosed with preeclampsia, your doctor may recommend additional tests to determine how well your liver and kidneys are functioning and to see if your blood has a normal number of platelets — the cells that help blood clot. Your doctor may also recommend close monitoring of your baby's growth, typically through ultrasound. This test combines high-frequency sound waves and computer processing to generate pictures of the inside of your uterus.
You may also need a nonstress test or biophysical profile to make sure your baby is getting enough oxygen and nourishment. A nonstress test is a simple procedure that checks how often your baby moves in a certain period of time and how much his or her heart rate increases with movement. A biophysical profile combines an ultrasound with a nonstress test to provide more information about your baby's breathing, tone, movement and the volume of amniotic fluid in your uterus.
Most women with preeclampsia deliver healthy babies. The more severe your preeclampsia and the earlier it occurs in your pregnancy, however, the greater the risks for you and your baby. Complications of preeclampsia may include :
- Lack of blood flow to the placenta. Preeclampsia affects the arteries carrying blood to the placenta. If the placenta doesn't get enough blood, the baby may receive less oxygen and nutrients. This can lead to slow growth, low birth weight, preterm birth or stillbirth.
- Placental abruption. Preeclampsia increases the risk of placental abruption, in which the placenta separates from the inner wall of the uterus before delivery. Severe abruption can cause heavy bleeding, which can be life-threatening for both mother and baby.
- HELLP syndrome. HELLP — which stands for hemolysis (the destruction of red blood cells), elevated liver enzymes and low platelet count — syndrome can rapidly become life-threatening for both mother and baby. Symptoms of HELLP syndrome include nausea and vomiting, headache and upper right abdominal pain. HELLP syndrome is particularly dangerous because it can occur before signs or symptoms of preeclampsia appear.
- Eclampsia. When preeclampsia isn't controlled, eclampsia — which is essentially preeclampsia plus seizures — can develop. Symptoms of eclampsia include upper right abdominal pain, severe headache, vision problems and change in mental status, such as decreased alertness. Eclampsia can permanently damage a mother's vital organs, including the brain, liver and kidneys. Left untreated, eclampsia can cause coma, brain damage and death for both mother and baby.
The only cure for preeclampsia is delivery. You're at increased risk of seizures, placental abruption and severe bleeding until your blood pressure decreases. Of course, if it's too early in your pregnancy, delivery may not be the best thing for your baby.
Bed rest: Buying time for baby to grow
If you aren't near the end of your pregnancy and you have a mild case of preeclampsia, your doctor may recommend bed rest to lower your blood pressure and increase blood flow to your placenta, giving your baby extra time to mature. You may need to lie in bed, only sitting and standing when necessary. Or you may be able to sit on the couch or in bed and strictly limit your activities. Your doctor may want to see you a few times a week to check your blood pressure, urine protein levels and your baby's well-being.
If you have more severe preeclampsia, you may need bed rest in the hospital. In the hospital, you may have regular nonstress tests or biophysical profiles to monitor your baby's well-being. You may also have ultrasound exams to measure the volume of amniotic fluid. A lack of amniotic fluid is a sign of poor blood supply to the baby.
Medications: Helpful for you and your baby
Your doctor may recommend medication to lower your blood pressure until delivery. If you have severe preeclampsia or HELLP syndrome, corticosteroid medications can temporarily improve liver and platelet functioning to help prolong your pregnancy. Corticosteroids can also help your baby's lungs become more mature in as little as 48 hours — an important step in helping a premature baby prepare for life outside the womb.
Delivery: The ultimate cure for preeclampsia
If you're diagnosed with preeclampsia near the end of your pregnancy, you may be treated by inducing labor right away. The readiness of your cervix — whether it's beginning to open (dilate), thin (efface) and soften (ripen) — also may be a factor in determining whether or when labor will be induced.
In more severe cases, it may not be possible to consider your baby's gestational age or the readiness of your cervix. If it's not possible to wait, your doctor may induce labor or schedule a C-section earlier in your pregnancy. During delivery, you may be given magnesium sulfate intravenously to increase uterine blood flow and prevent seizures.
After delivery, expect your blood pressure to return to normal within a few days or weeks.
There's no known way to prevent preeclampsia. Eating less salt or changing your activities during pregnancy doesn't reduce the risk. The best way to take care of yourself — and your baby — is to seek early and regular prenatal care. If preeclampsia is detected early, you and your doctor can work together to prevent complications and make the best choices for you and your baby.
In a preliminary 2006 study, women who took multivitamins and maintained a healthy weight before conception reduced the risk of developing preeclampsia during pregnancy by more than 70 percent compared with women of a healthy weight who didn't take multivitamins or with women who took multivitamins but were overweight before conception.
Several earlier studies suggested that specific nutritional supplements could prevent preeclampsia, but these studies haven't stood the test of time. Although a healthy weight before pregnancy has clear benefits for both mother and baby, more research is needed to determine the preventive effects of multivitamins and other nutritional supplements.