February 19, 2007

The Dangers of Preeclampsia
By Kim M. Norton
For The Record
Vol. 19 No. 3 P. 28

Close monitoring during pregnancy and continued involvement in the postpartum can reduce the risk of serious complications such as seizure and stroke.

Untreated hypertension can lead to serious complications such as an enlarged heart, kidney damage, atherosclerosis, stroke, and heart attack. Pregnant women who do not have a history of hypertension but develop it during the course of the pregnancy can acquire pregnancy-induced hypertension, or preeclampsia. If left untreated, it can lead to abruptio placentae, cerebral hemorrhage, cerebral vascular accident, acute renal failure, and intrauterine growth restrictions for the fetus.

Preeclampsia, often known as the disease of first pregnancies, is usually detected at approximately 20 weeks gestation. The mother must be monitored more closely and frequently to detect any consistent rise in blood pressure and evidence of proteinuria. In the past, the general knowledge about preeclampsia was that by delivering the child, the risk for preeclampsia and its complications are resolved. However, current research is finding otherwise.

“Preeclampsia can surface at any point in the pregnancy. Although it is often diagnosed about midway through the pregnancy, it can and does occur in the postpartum with severe complications if its signs and symptoms are ignored,” says John R. Barton, MD, a maternal-fetal medicine specialist at Central Baptist Hospital in Lexington, Ky. Although the mother who was preeclamptic during her pregnancy is likely to suffer some complications in the postpartum, this, too, is proving not to be the norm. Women who did not have preeclampsia but have some other unresolved or undiagnosed medical condition could develop postpartum or late-onset preeclampsia anywhere from 48 hours after delivery to three or four weeks postpartum, says Barton.

The majority of these women who return to the emergency department (ED) with severe headaches, shortness of breath, and epigastric pain do so around 10 days postpartum, but physicians are missing the diagnosis, explains Barton. “When a woman presents with any of these symptoms and has just had a child, it should raise a red flag and the physician should consider postpartum preeclampsia,” he says.

Defining Preeclampsia
“Preeclampsia occurs when the placenta abnormally invades the uterus by growing into the spiral arteries of the uterus incorrectly,” says Robert Atlas, MD, chair of the department of obstetrics and gynecology at Mercy Medical Center in Baltimore. In this instance, the body regards the placenta as a tumor and is resistant to high blood pressure, which can result in poor pregnancy outcome, he says.

Preeclampsia is generally diagnosed at roughly 20 weeks gestation and is characterized by a sustained blood pressure elevation of 140/90 millimeters of mercury after the 20th week of gestation that is recorded on two or more measurements, according to the American College of Obstetricians and Gynecologists (ACOG). In some circumstances, obstetricians can detect the onset of the disease with close follow-up of mothers deemed at risk, says Atlas.

Proteinuria is another indicator of preeclampsia. “It is defined as the excretion of 0.1 g of protein per liter (100 mg/L) in a random urine sample and 0.3 g/L (300mg/L) in a 24-hour specimen,” according to the ACOG. Evidence of proteinuria indicates a worsening of preeclampsia and increased risk of adverse outcomes for both the mother and her fetus, according to the authors of Association of Women’s Health, Obstetric and Neonatal Nurses’s Perinatal Nursing. The final indication that points to preeclampsia is edema. Although edema is a common complication during pregnancy, when the swelling causes increased amounts of fluid in the tissue, it can lead to vasospasms that could increase the risk of pulmonary edema.

“There is no known cause for preeclampsia, but it is believed that the presence of a foreign object, in this case the placenta and fetus, is the trigger. Preeclampsia is the body’s response to the unborn child,” explains Nancy Powell, RN, MSN, CNM, clinical educator at Shore Memorial Hospital in Somers Point, N.J. Numerous risk factors and genetics are strong indicators of whether a woman is susceptible to the disease, she adds.

Postpartum Preeclampsia
Some clinicians and physicians are puzzled by postpartum preeclampsia. In their experience, preeclampsia is “cured” with the delivery of the child. But recent research shows that in some women, preeclampsia may develop in the postpartum or worsen following a pregnancy in which preeclampsia was a factor.

Barton and his colleagues have researched postpartum preeclampsia and determined that late-onset preeclampsia can be prevented with “prompt reporting and evaluation of symptoms of preeclampsia in the postpartum.” There has been an increase in the number of postpartum preeclampsia cases, and Barton believes this could be due in part to the limited amount of time the mother spends in the hospital after giving birth and the gap between discharge and follow-up at her obstetrician’s office.

It is not known what prompts preeclampsia in the postpartum—it appears to affect mothers who deliver vaginally, with or without an epidural or spinal, and mothers who deliver by cesarean section. However, the mother who delivers via a cesarean loses twice as much blood as the mother who delivers vaginally. This may lower blood pressure and mask the symptoms of preeclampsia, according to Barton.

“Symptoms of late-onset preeclampsia can occur at any time once the mother goes into labor. She can have increased blood pressure during labor, immediately following delivery, or up to four weeks after delivering,” says Barton. Careful postpartum monitoring of the new mother can reduce the number of preeclampsia-induced complications, if healthcare providers are aware of the signs and symptoms, he says.

Postpartum Signs and Symptoms
“Any woman who has recently given birth and has an elevated blood pressure reading; complains of severe, constant headaches; has blurry vision; or epigastric pain should be evaluated for postpartum preeclampsia,” says Barton. Thorough blood tests could indicate kidney failure, liver damage, and platelet problems, all of which indicate postpartum preeclampsia, explains Randy A. Fink, MD, a gynecologist/obstetrician in Miami. Other symptoms include black spots in front of the eyes and pain in the middle of the stomach that radiates up to the shoulder, possibly indicating poor liver function or failure, says Fink.

While most women who return to the ED do so within the first 10 days after giving birth, there is a chance the disease could strike later. Late-onset preeclampsia is generally an extension of hypertension from pregnancy, but in some cases the mother will develop high blood pressure following birth, even though it was not an issue during the prenatal period.

Other causes of high blood pressure after giving birth could arise from undiagnosed medical conditions such as kidney disease, rheumatoid disease, diabetes, and obesity or morbid obesity, explains Atlas.

If the signs and symptoms of postpartum preeclampsia are ignored, the mother can suffer such complications as a stroke, due to a brain bleed or ruptured blood vessel, or a seizure. “The risk for seizures or other brain events generally decreases 24 to 48 hours postpartum,” says Fink. If it is known beforehand that the mother is having an issue with hypertension, magnesium sulfate can be administered to control her blood pressure. If, after the mother gives birth, there is still a concern of elevated blood pressure, hypertensive drugs should be used to control her blood pressure, he says.

The postpartum preeclampsia diagnosis would change to chronic hypertension if the diagnosis persists past the 42nd day, according to Powell. At that point, pharmacological therapy and lifestyle changes would be the most effective course of treatment.

Risk Factors
There are several factors contributing to an increased risk of preeclampsia. These can include the following:

• genetic predisposition (daughters of preeclamptic mothers and first-degree relatives who had preeclampsia are at the highest risk of developing the disease);

• first-time mothers;

• African American and Native American women;

• preexisting hypertension, diabetes, or kidney disease;

• a previous pregnancy with preeclampsia (If the mother was diagnosed in her first pregnancy prior to 20 weeks gestation, there is a significant risk she will become preeclamptic in subsequent pregnancies.);

• a woman with a body mass index (BMI) of 30 or above has a high risk, and a woman with a BMI of 35 or higher has the greatest risk; and

• fertility treatments. (There is a possible connection between these treatments and the risk of preeclampsia due to the higher incidence of multiples.)

Good prenatal care and a thorough exam prior to conception can be extremely helpful in the early diagnosis and detection of preeclampsia or any other medical issue that could complicate a pregnancy. If a woman has chronic hypertension prior to becoming pregnant, her blood pressure will be monitored more closely and any elevation in the pressure could require pharmacologic intervention or bed rest. “Women who are at risk of developing the disease should watch their diet to control excessive weight gain. Exercise, such as walking, and periods of rest are important to help manage the progression of the disease,” explains Powell.

Cardiovascular Implications Beyond Pregnancy
For the 5% to 8% of women who are affected by preeclampsia, there are long-term health considerations beyond the child’s birth. Various studies from Europe and Scandinavia have shown a correlation between mothers who had preeclampsia and the incidence of cardiovascular disease later in life. “It is important for the woman who had preeclampsia to be monitored more closely as she ages for the risk of cardiovascular disease,” explains Atlas.

Supplements to Consider and Avoid
Depending on the disease severity, the management varies. There have been several nonpharmacological therapies shown to be helpful in the prevention or, at the least, the progression of preeclampsia. “Eight milligrams of baby aspirin can be of some benefit to the at-risk mother as well as 2 grams of calcium daily,” says Atlas. Women should avoid taking vitamin E while pregnant because of the higher risk of developing preeclampsia, Atlas adds.

Further Research
Although there are several defined risk factors associated with preeclampsia, there is no definitive cause contributing to the disease’s manifestation. Researchers are looking into isolating a chromosome that may be a genetic link to the susceptibility of developing preeclampsia. Currently, there is no diagnostic test available to determine if a woman will develop preeclampsia. Rather, researchers are looking at genetic predisposition and risk factors that can lead to a diagnosis midway through gestation, explains Eric Moses, PhD, a molecular geneticist with the Southwest Foundation for Biomedical Research in San Antonio.

“If we are able to isolate the chromosome that causes preeclampsia, there is the hope that we would be able to identify women with the gene early in pregnancy or prior to pregnancy to be able to monitor them more closely, to reduce or eliminate the onset of symptoms of the preeclampsia,” he says. The possibility of improved preventative care is there, but currently there are no such options available, adds Moses.

— Kim M. Norton is a New Jersey-based freelance writer specializing in healthcare related topics for various trade and consumer publications.

Resources
Chames MC, Livingston JC, Ivester TS, et al. Late postpartum eclampsia: A preventable disease? Am J Obstet Gynecol. 2002; 186(6):1174-1177.

Irgens HU, Reisaeter L, Irgens LM, et al. Long term mortality of mothers and fathers after pre-eclampsia: Population based cohort study. BMJ. 2001;323(7323):1213-1217.

Lubarsky SL, Barton JR, Friedman SA, et al. Late postpartum eclampsia revisited. Obstet Gynecol. 1994;83(4):502-505.

Matthys LA, Coppage KH, Lambers DS, et al. Delayed postpartum preeclampsia: An experience of 151 cases. Am J Obstet Gynecol. 2004; 190(5):1464-1466.

Simpson KR, Creehan PA. Association of Women’s Health, Obstetric and Neonatal Nurses’ Perinatal Nursing. Philadelphia: Lippincott Williams & Wilkins and Association of Women’s Health, Obstetric and Neonatal Nurses. 2001;173-190.

Wilson BJ, Watson MS, Prescott GJ, et al. Hypertensive diseases of pregnancy and risk of hypertension and stroke in later life: Results from cohort study. BMJ. 2003;326(7394):845.

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Severe Preeclampsia Warning Signs
• A systolic blood pressure of 160 millimeters of mercury (mm/Hg) or diastolic blood pressure of 110 mm/Hg on two occasions at least six hours apart

• Proteinuria of 5 grams or greater in 24 hours or 3 to 4-plus on a dipstick

• Intrauterine growth restriction

• Cerebral or visual disturbances

• Impaired liver function demonstrated by right upper quadrant or epigastric pain or altered liver function tests

• Pulmonary edema, cyanosis, chest pain, or cardiac dysrhythmias

• Development of eclampsia

• Development of HELLP (hemolytic anemia, elevated liver enzymes, and low platelets syndrome)

Late-Onset or Postpartum Preeclampsia Warning Signs
• A systolic blood pressure of 140 millimeters of mercury (mm/Hg) or diastolic blood pressure of 90 mm/Hg after 48 hours of giving birth for a mild case and a systolic blood pressure of 160mm/Hg or diastolic blood pressure of 110 mm/Hg for a severe case

• An unrelenting, persistent headache (patient will likely claim that it is “the worst headache of my life”)

• Shortness of breath

• Epigastric pain or pain in the chest

— KMN