Obstetrics Normal And Problem Pregnancies

[Eboni Kleifgen]

Atthe mild end of the spectrum is gestational hypertension, which occurs when a woman who previously had normal blood pressure develops high blood pressure when she is more than 20 weeks pregnant and her blood pressure returns to normal within 12 weeks after delivery. This problem usually occurs without other symptoms. In many cases, gestational hypertension does not harm the mother or fetus. Severe gestational hypertension, however, may be associated with preterm birth and infants who are small for their age at birth.1 Some women who have gestational hypertension later develop preeclampsia.2,3,4

Preeclampsia is similar to gestational hypertension because it also involves high blood pressure at or after 20 weeks of pregnancy in a woman whose blood pressure was normal before pregnancy. But preeclampsia can also include blood pressure at or greater than 140/90 mmHg, increased swelling, and protein in the urine.5,6 The condition can be serious and is a leading cause of preterm birth (before 37 weeks of pregnancy).7 If it is severe enough to affect brain function, causing seizures or coma, it is called eclampsia.

A serious complication of hypertensive disorders in pregnancy is HELLP syndrome, a situation in which a pregnant woman with preeclampsia or eclampsia suffers damage to the liver and blood cells. The letters in the name HELLP stand for the following problems:

Postpartum preeclampsia describes preeclampsia that develops after the baby is delivered, usually between 48 hours and 6 weeks after delivery.8 Symptoms can include high blood pressure, severe headache, visual changes, upper abdominal pain, and nausea or vomiting.5,6 Postpartum preeclampsia can occur regardless of whether a woman had high blood pressure or preeclampsia during pregnancy.9

Postpartum eclampsia refers to seizures that occur between 48 and 72 hours after delivery. Symptoms also include high blood pressure and difficulty breathing.5,6 About one-third of eclampsia cases occur after delivery, and nearly half of those are more than 48 hours after the birth.10

Women with preeclampsia are at increased risk for damage to the kidneys, liver, brain, and other organ and blood systems. Preeclampsia may also affect the placenta. The condition could lead to a separation of the placenta from the uterus (referred to as placental abruption), preterm birth, and pregnancy loss or stillbirth. In some cases, preeclampsia can lead to organ failure or stroke.

In severe cases, preeclampsia can develop into eclampsia, which includes seizures. Seizures in eclampsia may cause a woman to lose consciousness and twitch uncontrollably.2 If the fetus is not delivered, these conditions can cause the death of the mother and/or the fetus.

Although most pregnant women in developed countries survive preeclampsia, it is still a major cause of illness and death globally.3 According to the World Health Organization, preeclampsia and eclampsia cause 14% of maternal deaths each year, or about 50,000 to 75,000 women worldwide.4

In "uncomplicated preeclampsia," the mother's high blood pressure and other symptoms usually go back to normal within 6 weeks of the infant's birth. However, studies have shown that women who had preeclampsia are four times more likely to later develop hypertension (high blood pressure) and are twice as likely to later develop ischemic heart disease (reduced blood supply to the heart muscle, which can cause heart attacks), a blood clot in a vein, and stroke as are women who did not have preeclampsia.5

Less commonly, mothers who had preeclampsia can experience permanent damage to their organs, such as their kidneys and liver. They can also experience fluid in the lungs. In the days following birth, women with preeclampsia remain at increased risk for developing eclampsia and seizures.3,6

Infants whose mothers had preeclampsia are also at increased risk for later problems, even if they were born at full term (39 weeks of pregnancy).3 Infants born preterm due to preeclampsia face a higher risk of some long-term health issues, mostly related to being born early, including learning disorders, cerebral palsy, epilepsy, deafness, and blindness. Infants born preterm may also have to be hospitalized for a long time after birth and may be smaller than infants born full term. Infants who experienced poor growth in the uterus may later be at higher risk of diabetes, congestive heart failure, and high blood pressure.4

Preeclampsia is also more common among women who have histories of certain health conditions, such as migraines,8 diabetes,9 rheumatoid arthritis,10 lupus,11 scleroderma,12 urinary tract infections,13 gum disease,14 polycystic ovary syndrome,15 multiple sclerosis, gestational diabetes, and sickle cell disease.16

The U.S. Preventative Services Task Force recommends that women who are at high risk for preeclampsia take low-dose aspirin starting after 12 weeks of pregnancy to prevent preeclampsia.17 Women who are pregnant or who are thinking about getting pregnant should talk with their health care provider about preeclampsia risk and ways to reduce the risk.

A pregnant woman with HELLP syndrome might bleed or bruise easily and/or experience abdominal pain, nausea or vomiting, headache, or extreme fatigue. Although most women who develop HELLP syndrome already have high blood pressure and preeclampsia, sometimes the syndrome is the first sign. In addition, HELLP syndrome can occur without a woman having either high blood pressure or protein in her urine.

A health care provider will check a pregnant woman's blood pressure and urine during each prenatal visit. If the blood pressure reading is considered high (140/90 or higher), especially after the 20th week of pregnancy, the health care provider will likely perform blood tests and more extensive lab tests to look for extra protein in the urine (called proteinuria) as well as other symptoms.

Gestational hypertension is diagnosed if a pregnant woman has high blood pressure but no protein in the urine. Gestational hypertension occurs when women whose blood pressure levels were normal before pregnancy develop high blood pressure after 20 weeks of pregnancy. Gestational hypertension can progress into preeclampsia.1

HELLP syndrome is diagnosed when laboratory tests show hemolysis (burst red blood cells release hemoglobin into the blood plasma), elevated liver enzymes, and low platelets. There also may or may not be extra protein in the urine.5

Treatment decisions for preeclampsia, eclampsia, and HELLP syndrome need to take into account how severe the condition is, the potential for maternal complications, how far along the pregnancy is, and the potential risks to the fetus. Ideally, the healthcare provider will minimize risks to the mother while giving the fetus as much time as possible to mature before delivery.

If the pregnancy is at less than 37 weeks, however, the woman and her healthcare provider may consider treatment options that give the fetus more time to develop, depending on how severe the condition is. A healthcare provider may consider the following options:

When a woman has severe preeclampsia and is at 34 weeks of pregnancy or later, the American College of Obstetricians and Gynecologists recommends delivery as soon as medically possible. If the pregnancy is at less than 34 weeks, healthcare providers will probably prescribe corticosteroids to help speed up the maturation of the fetal lungs before attempting delivery.2

HELLP syndrome, a severe complication of preeclampsia and eclampsia, can lead to serious complications for the mother, including liver failure and death, as well as the fetus. The healthcare provider may consider the following treatments after a diagnosis of HELLP syndrome:

As mentioned earlier, some women develop preeclampsia or eclampsia after they deliver their babies. The American College of Obstetricians and Gynecologists recommends that healthcare providers closely monitor women who had high blood pressure or preeclampsia during pregnancy for 72 hours after delivery, either at home or in the hospital.5 Because postpartum preeclampsia and eclampsia can progress quickly and can have serious effects, it is important to get treatment immediately.

One study looked at women who came to the emergency room with a diagnosis of postpartum preeclampsia. The most common warning symptoms in these cases were headache, vision changes, and nausea or abdominal pain. Nearly all of these women had high blood pressure when admitted, and some had already had seizures at home before coming to the hospital. Treatment for postpartum preeclampsia follows the guidelines used to treat preeclampsia during pregnancy. The women in the study received magnesium sulfate to treat or prevent seizure and, if needed, additional treatment for their high blood pressure.6

Complications of preeclampsia, such as kidney failure, hemorrhage, and stroke, can lead to lasting health problems. Worldwide, preeclampsia is one of the leading causes of maternal death. NICHD aims to maintain a global perspective while pursuing a better understanding of hypertensive disorders in pregnancy to prevent the poor health outcomes and deaths caused by this condition.

Researchers at NICHD's Division of Intramural Population Health Research (DIPHR) found strong evidence that an imbalance of two proteins produced by the placenta is responsible for the symptoms of preeclampsia. Abnormally high levels of these proteins appear to deprive the blood vessels of substances needed to keep the lining of the blood vessels healthy. Deprived of these essential substances, the cells lining the blood vessels begin to sicken and die. As a result, blood pressure increases, and the blood vessels leach protein into the tissues and urine. Both proteins appear to contribute to the development of preeclampsia. Severe disease usually occurs in women with high levels of both measures and not in women with high levels of only one or the other. (PMID: 16957146)

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