Preeclampsia

Alternative names: Toxemia; Pregnancy-induced hypertension

Definition
Preeclampsia is the development of elevated blood pressure and protein in the urine after the 20th week of pregnancy. It may be associated with swelling of the face and hands.

Causes, incidence, and risk factors

The exact cause of preeclampsia is not known. Many unproved theories of potential causes exist, including genetic, dietary, vascular (blood vessel), and autoimmune factors.

Preeclampsia occurs in approximately 8% of all pregnancies. Increased risk is associated with first pregnancies, advanced maternal age, African-American heritage, multiple pregnancies, and a past history of diabetes, high blood pressure, or kidney disease.

Symptoms

* Edema (swelling of the hands and face present upon arising)
* Weight gain
* In excess of 2 pounds per week
* Of sudden onset, over 1 to 2 days
* Headaches
Note: Some swelling of the feet and ankles is considered normal with pregnancy.

Additional symptoms that may be associated with this disease:

* Decreased urine output
* Nausea and vomiting
* Facial swelling
* High blood pressure
* Agitation
* Vision changes (flashing lights in the eyes)
* Abdominal pain

Signs and tests

* Documented weight gain
* Swelling in the upper body
* Elevated blood pressure
* Proteinuria (protein noted in urine)
* Thrombocytopenia (platelet count less than 100,000)
* Elevated liver function tests
* Preeclampsia may also alter the results of some laboratory tests.

Treatment

Currently, the only way to cure preeclampsia is to deliver the baby. However, if that delivery would be very premature, the disease may be managed by bed rest, close monitoring, and delivery as soon as the fetus has a good chance of surviving outside the womb.

Patients are usually hospitalized, but occasionally they may be managed on an outpatient basis with careful monitoring of blood pressure, urine checks for protein, and weight.

Optimally, attempts are made to manage the condition until a delivery after 36 weeks of pregnancy can be achieved.

Labor may be induced if any of the following occur:

* Diastolic blood pressure greater than 100 mmHg consistently for a 24 hour period, or any confirmed reading over 110 mmHg
* Persistent or severe headache
* Abdominal pain
* Abnormal liver function tests
* Rising serum creatinine
* HELLP syndrome
* Pulmonary edema (fluid in lungs)
* Eclampsia
* Thrombocytopenia (low platelet count)
* Non-reassuring fetal monitoring tracings
* Failure of fetal growth noted by ultrasound
* Abnormal biophysical profile (a test to monitor the health of the fetus)

In cases of severe preeclampsia when the pregnancy is between 32 and 34 weeks, delivery is the treatment of choice. For pregnancies less than 24 weeks, the induction of labor is recommended, although the likelihood that the fetus will survive is very small.

Prolonging pregnancies has been shown to result in maternal complications, as well as infant death in approximately 87% of cases. Pregnancies between 24 and 34 weeks gestation present a "gray zone," and the medical team and the parents may decide to attempt to delay delivery in order to allow the fetus to mature.

During this time, the mother is treated with steroid injections which help speed the maturity of some fetal organs including the lungs. The mother and baby are closely monitored for complications.

During induction of labor and delivery, medications are given to prevent seizures and to keep blood pressure under good control. The decision for vaginal delivery versus Cesarean section is based on how well the fetus is able to tolerate labor.

Expectations (prognosis)

Maternal deaths caused by preeclampsia are rare in the U.S. Fetal or perinatal deaths are high and generally decrease as the fetus matures. The risk of recurrent preeclampsia in subsequent pregnancies is approximately 33%. Preeclampsia does not appear to lead to chronic high blood pressure.

Complications

Preeclampsia may develop into eclampsia, the occurrence of seizures. Fetal complications may occur because of prematurity at time of delivery.

Calling your health care provider

Call your health care provider if symptoms occur during pregnancy.

Prevention

Although there are currently no known prevention methods, it is important for all pregnant women to obtain early and ongoing prenatal care. This allows for the early recognition and treatment of conditions such as preeclampsia.


Update Date: 8/8/2005

Updated by: Sharon Roseanne Thompson, M.D., M.P.H., Clinical Fellow, Department of Obstetrics & Gynecology, Brigham and Women's Hospital, Boston, MA. Review provided by VeriMed Healthcare Network.


Source: http://www.nlm.nih.gov/medlineplus/ency/article/000898.htm