- pregnancy-induced hypertension (PIH)
Preeclampsia is a condition in which high blood pressure (pregnancy-induced hypertension), proteinuria (protein in the urine), edema (swelling) and excessive weight gain occur during pregnancy. The condition usually occurs after the 20th week of pregnancy.
What is going on in the body?
The placenta is the spongy material in the mother's uterus that nourishes the fetus. Some experts believe that a problem with the placenta causes preeclampsia. The mother has spasms of the blood vessels, which increase her blood pressure. The blood flow to the placenta is impaired. If the blood pressure is not controlled, it can damage the placenta and cause death of the baby.
Preeclampsia develops in 5% of pregnant women. It usually occurs after the 20th week of pregnancy. It may be mild or severe. The high blood pressure can affect the brain, kidneys, liver, and lungs.
If the woman develops seizures or coma, the condition is known as eclampsia.
What are the causes and risks of the condition?
Factors that increase a woman's risk of preeclampsia are:
a first pregnancy
African American ethnicity
high blood pressure or chronic renal disease before pregnancy
family history of pregnancy-induced hypertension
low socioeconomic status
maternal age below 20 or over 35
molar pregnancy, an abnormal condition that mimics a normal pregnancy but is actually a tumor
multiple gestation such as twins or triplets
preeclampsia or eclampsia in previous pregnancies
she or the baby's father was born of a pregnancy with preeclampsia or eclampsia
one of the thrombophilias
No one knows why some women with preeclampsia develop the seizures associated with eclampsia. Theories about why seizures might occur in pregnancy involve:
small clots that block blood vessels in the brain and restrict oxygen
narrowing of tiny arteries in the brain
areas of bleeding in the brain
high blood pressure
- a problem with the brain or nervous system
What can be done to prevent the condition?
There are no known ways to prevent preeclampsia. All pregnant women should have early prenatal care. Blood pressure changes should be watched closely.
How is the condition diagnosed?
Diagnosis of preeclampsia begins with a medical history and physical exam. The woman's blood pressure
will be measured. The healthcare provider may order the following tests:
- blood tests to check clotting and liver function
- complete blood count, or CBC, to look for abnormal blood cell counts
- cranial CT scan to check for bleeding or stroke
- pregnancy ultrasound to check the age and condition of the baby
- urinalysis to look for protein in the urine
Long Term Effects
What are the long-term effects of the condition?
Preeclampsia may cause pregnancy complications, including the following:
increased risk for cesarean birth
intrauterine growth restriction (IUGR), a lack of normal growth of the baby within the womb
placenta abruptio, or separation of the placenta from the uterine wall
- suffocation at birth, or asphyxia
Preeclampsia can also cause the following health problems that affect both mother and baby:
- acute renal failure, or kidney failure
- disseminated intravascular coagulation, or DIC, a clotting problem that causes widespread bleeding
- eclampsia, with high blood pressure, coma, and seizures
- HELLP syndrome, which includes liver and blood disorders
- intracerebral hemorrhage and stroke
What are the risks to others?
Preeclampsia is not contagious. Both mother and baby are at risk for complications of preeclampsia.
What are the treatments for the condition?
Giving birth is the only cure for preeclampsia. Preeclampsia limits blood flow to the placenta and the baby. If a woman has symptoms, flow may already be reduced by 50%.
The healthcare provider may decide to induce labor or to wait for labor to occur naturally. The following factors will determine the decision:
condition of the mother and her baby
dilation of the cervix
failure of growth of the baby in the uterus as measured by pregnancy ultrasounds
gestational age of the baby
distress of the baby
fluid in the lungs
presence of labor
severity of the condition
- the wishes of the mother
If the symptoms are mild, outpatient treatment is common. This includes bed rest at home and biweekly exams in the provider's office. If symptoms do not improve, hospitalization may be needed.
Testing of the unborn child will be done to decide if early delivery is possible. In severe cases, the provider may decide to induce labor with medications.
Delivery may be induced if any of the following conditions occur:
destruction of red blood cells, known as hemolysis
elevated liver function tests
falling platelet count
pain in the right upper abdomen
persistent and severe headache
signs of kidney failure
- very high blood pressure for more than 24 hours
Treating severe preeclampsia means controlling the woman's blood pressure. A Cesarean birth may be needed. Medications to treat eclampsia include intravenous magnesium sulfate, hydralazine (i.e., Apresoline), and, if necessary, diazoxide (i.e., Hyperstat, Proglycem). Anticonvulsants may be used to prevent seizures.
What are the side effects of the treatments?
A cesarean birth may cause bleeding, infection, or even death. Medicines used to treat eclampsia may cause low blood pressure, breathing difficulties, nausea, or allergic reactions.
What happens after treatment for the condition?
After the baby is born, a woman may still have seizures for up to 6 weeks. Her provider will closely monitor blood pressure, urine and blood tests, and any other symptoms. If a baby is born prematurely and has health problems, hospitalization and care will be needed.
Twenty-five percent of women with eclampsia will have hypertension in subsequent pregnancies, but only 5% of these will be sever and only 2% will be eclamptic again.
Also, multiparous women with eclampsia (eclampsia in a pregnancy that is not the first pregnancy) are at higher risk for essential hypertension later in life and are at a higher risk for higher mortality in subsequent pregnancies.
How is the condition monitored?
Preeclampsia may recur in later pregnancies. Early prenatal care is key to recognizing warning signs and managing the condition. Any new or worsening symptoms should be reported to the healthcare provider.