What is preeclampsia
Preeclampsia, also spelled pre-eclampsia, is a potentially serious condition that affects only pregnant women after the 20th week of pregnancy or shortly after delivery. Its characteristic symptoms are sudden-onset proteinuria (protein in the urine) and hypertension (high blood pressure). It is not yet known for certain what causes preeclampsia, but it may have something to do with abnormalities of the placental blood supply. Preeclampsia may also occur alongside HELLP syndrome, which is very serious and may progress to eclampsia, which is also very serious and may be fatal.
Preeclampsia affects only between about two and eight of every 100 pregnant women. Severe preeclampsia affects only about one in every 200 pregnancies. HELLP Syndrome has a similar incidence, but around half of women with severe preeclampsia will develop HELLP Syndrome. Rates of eclampsia are low in most developed countries, with an incidence of around one in every 2000 pregnancies. However, the rate is considerably higher in developing countries.
- Hypertension (high blood pressure). A blood pressure of 140 over 90 is considered a sign in women who do not have pre-existing hypertension.
- Proteinuria (protein in the urine). This is defined as 300mg or more of protein passed in the urine over 24 hours.
Foamy urine is a sign of proteinuria. If a pregnant woman finds that her urine is foamy, she should consult a physician as soon as possible. Other symptoms which may appear as the disorder worsens include:
- Headache that cannot be alleviated with painkillers
- Edema (swelling) of hands, arms, face and/or feet
- Blurred vision or blind spots
- Confusion or disorientation
- Nausea and vomiting
- Pain in the upper right abdomen, just below the ribs
- Heartburn that cannot be alleviated by antacids
- Feeling of great unwellness
- Oliguria (low urine output) of 500ml or less over 24 hours
- Being unable to feel the baby move as much as previously
- Shortness of breath, possibly due to pulmonary edema (excess fluid in the lungs)
- Stroke. This is very rare
Good to know: If a pregnant person suddenly discovers that their watch, bracelets or rings no longer fit their arm or hand, or that their sleeves are suddenly tight, they should seek medical help immediately.
It should be noted that not all painkillers are safe for use in pregnancy. Pregnant women should consult with their doctor about what pain-relieving measures might work for them. If a pregnant woman has a headache that does not resolve on its own within a reasonable time, they should contact their care provider.
If any of these symptoms appear, the affected person should receive medical help as soon as possible. Without treatment, preeclampsia may become eclampsia, which is very serious and may be fatal.
Hypertension, proteinuria and heartburn
Many women have hypertension during pregnancy, without having preeclampsia. Hypertension that results from preeclampsia is normally distinguishable from pre-existing or chronic hypertension by its sudden onset. It is possible for preeclampsia-related hypertension to be superimposed on chronic hypertension. It may be quite difficult to diagnose preeclampsia in women with chronic hypertension.
Likewise, it may be hard to diagnose accurately in women with pre-existing proteinuria or renal diseases. One indication may be a sudden upward spike in the levels of protein being excreted.
Heartburn is also quite common among pregnant people who do not have preeclampsia. Heartburn resulting from preeclampsia can be distinguished from other heartburn by its resistance to antacid treatment.
In all of these cases, if proteinuria is present, preeclampsia is also likely to be present.
Most women with preeclampsia will not go on to develop severe preeclampsia if they are promptly treated. Signs and symptoms which can indicate severe preeclampsia include:
- Worsening physical symptoms, as listed above
- Renal insufficiency due to kidney damage from high blood pressure
- Moderate to severe thrombocytopenia, i.e.low platelet count of 100 000 or lower
- Twice the normal serum levels of aspartate transaminase (AST) or alanine aminotransferase (ALT) (enzymes found in the liver)
In mothers with severe preeclampsia, the unborn baby usually suffers from reduced oxygen and nutrient supply, which can retard fetal growth. Babies can be measured by medical practitioners to determine whether they are small for gestational age.
The cause of preeclampsia is not yet completely understood by doctors. It appears to involve inflammation of maternal blood vessels, particularly those in the kidneys. This may be due to abnormalities in the way that the placental blood supply develops, which can impact the effectiveness of the attachment of the placenta to the uterine wall. An imperfect attachment may cause inflammatory substances to be released into the mother’s bloodstream. It is not yet known whether preeclampsia is caused by these abnormalities or whether these abnormalities and preeclampsia share a cause.
There is some evidence that preeclampsia and heart disease share some risk factors, namely:
- Endothelial dysfunction (dysfunction of the lining of the blood vessels and lymph glands)
- Insulin resistance
- Dyslipidemia (high levels of lipids in the blood).
There also appears to be a genetic component. If a pregnant person’s mother and/or sisters have a history of preeclampsia, their risk of preeclampsia is higher than that of a person without such a family history. Having had a previous pregnancy with preeclampsia also increases risk. In such high-risk pregnancies, there is some evidence that a daily low dose (81mg/day) of aspirin may have a protective effect.
- Have diabetes (type 1, type 2 or gestational diabetes)
- Are pregnant for the first time
- Are pregnant for the first time in 10 years
- Are having a multiple pregnancy of twins, triplets, etc.
- Have a BMI of 35 or greater, or body weight of 90kg or greater
- Are older than 40 or younger than 17 years old
- Have existing high blood pressure
- Have existing kidney disease
- Have existing vascular disorders
- Have existing clotting disorders
- Have a history of preeclampsia
- Have a family history of preeclampsia
Most cases of preeclampsia are relatively mild and can be treated without much danger to the mother or the unborn baby. However, in some cases the situation can become more severe. HELLP Syndrome and eclampsia are two serious complications of eclampsia.
HELLP syndrome may be considered a very severe form of preeclampsia, or a separate but overlapping disorder. The acronym HELLP stands for “hemolysis, elevated liver enzymes, low platelet count”, which refer to the main features of the condition. HELLP tends to have sudden onset with similar symptoms to preeclampsia.
- Nausea and vomiting
- Pain in the upper abdominal (stomach) region
- Vision problems
- Bruising easily or purple spots on the skin
- Tender or swollen liver
- High blood pressure
Signs that can be determined only by testing include:
- Hemolysis (disintegrating blood cells)
- Raised enzyme levels
- Thrombocytopenia (low blood platelet count)
HELLP Syndrome can occur at any point after 20 weeks of pregnancy, but is most common between 27 and 37 weeks. However, almost a third of cases occur only after delivery. Long-term complications can include:
- Retarded fetal growth
- Placental abruption, i.e. separation of placenta from uterine wall before labor
- Blood clotting problems
- Eclampsia, i.e. seizures in pregnant women with high blood pressure
- Liver failure
Placental abruption can reduce the supply of oxygen and nutrients to the unborn baby, increasing the risk of retarded fetal growth. In severe cases, the unborn child may not survive.
Eclampsia is diagnosed when a pregnant person with preeclampsia begins to have seizures.. In most cases, the person with eclampsia will have shown symptoms of severe preeclampsia, but in some cases no prior symptoms of preeclampsia appear. If eclampsia is not treated rapidly, it can lead to maternal coma, brain damage, and death.
Treatment and care
Treatment for preeclampsia involves balancing the severity of the preeclampsia with the risks facing the baby. The only total cure is to deliver the baby and placenta. If it is safe to do so for both the mother and the baby, the pregnancy will be maintained until the natural end of gestation, around 37 weeks. Only if the life of the mother or the baby is in danger will labor be induced early. However, if the baby is still too young to survive outside the womb, the medical care team will take steps to maintain the pregnancy until it is safe to deliver and if it is safe for the mother to do so.
In cases of mild preeclampsia, a short period of initial hospitalization may be followed by home care as an outpatient, often extending until the baby is delivered. Home care includes:
- Bed rest
- Regular blood pressure tests
- Regular fetal nonstress tests (NSTs) to check on the baby’s health
- Visits to a physician two or three times a week
It can also be helpful to increase the amount of protein eaten, minimize salt intake and ensure that enough water is consumed to stay well-hydrated.
When home care is not advisable due to the severity of the symptoms, people with preeclampsia will usually be hospitalized. The treatment concentrates on managing hypertension and monitoring for complications. Treatment includes:
- Medication to lower blood pressure, such as hydralazine, labetalol and nifedipine
- Blood pressure tests at intervals of four hours, or, in severe cases, every 15 to 30 minutes
- Urine tests for protein
- Monitoring of hydration
- Blood tests to monitor platelet count, clotting factors, and kidney and liver function
If preeclampsia occurs in late pregnancy, labor may be induced if the baby or the mother have blood pressure levels that cannot be controlled until the baby comes to full term. In such cases, the baby may be delivered, vaginally or by cesarean section.In cases where the baby is only a few weeks premature, the risks to the baby’s health are low. However, if the baby is less than 34 weeks along, it is the severity of the mother’s preeclampsia that will determine whether the medical team opts to deliver the baby. Outcomes for the baby may improve if the pregnancy is maintained, but treatment should not be at the expense of maternal wellbeing.
In some cases, corticosteroids may be administered to boost the baby’s lung development in order to allow it to be safely delivered earlier. If corticosteroid treatment is undertaken, the baby’s heart rate should be monitored very closely. If they are not thriving in the womb and have a better chance of survival if delivered, labor should be induced.
If HELLP syndrome is present, delivery will be induced regardless.
In cases of eclampsia, also, delivery should not be postponed unless the mother is in an unstable condition, in which case the mother should be stabilized before delivery is attempted. This should be done regardless of whether or not the baby is distressed.
In cases of eclampsia, the mother’s oxygen intake and seizures should be brought under control before delivery. Both baby and mother will need to be in a high-dependency unit for at least 24 hours after birth. Seizures can be prevented with an intravenous dose of magnesium sulfate, and may be broken using lorazepam or diazepam. Magnesium sulfate can have serious side effects and should only be administered by a skilled practitioner.
Preeclampsia after delivery
Most instances of preeclampsia happen before the baby is born, and subside soon after delivery. However, in a minority of cases, preeclampsia occurs only after delivery. If this happens, the affected person will be placed in a hospital high-dependency unit and monitored for signs of eclampsia. Once the medical team has established that they are not at risk of eclampsia, they will remain in hospital to be monitored for hypertension and further complications.
Good to know: In cases of postpartum preeclampsia, the baby is likely to be unaffected.
Q: What are the long-term complications for people who have had preeclampsia?
A: There is some evidence that people who had preeclampsia, eclampsia or HELLP syndrome may be at increased risk of hypertension and heart disease in later life. It may also increase the risk of stroke.
Q: Will my preeclampsia have long-term effects on my child once they are born? A: Children born to mothers with preeclampsia may be at increased risk of endocrine and nutritional diseases, which can affect height and weight gain.
American College of Gynecologists. “Practice Advisory on Low-Dose Aspirin and Prevention of Preeclampsia: Updated Recommendations.”. 11 July 2016. Accessed 14 April 2018. ↩
Obstetrics and Gynecology. [“Incidence, risk factors, and associated complications of eclampsia.”]https://www.ncbi.nlm.nih.gov/pubmed?term=22015865). November 2011. Accessed 13 April 2018. ↩
Obstetrics and Gynecology. “Use of corticosteroids in pregnancy-induced hypertension.”. February 1980. Accessed 14 April 2018. ↩
American Journal of Obstetrics and Gynecology. “Health of children born to mothers who had preeclampsia: a population-based cohort study”. September 2009. Accessed 08 May 2018. ↩
PLoS One. “Exposure to preeclampsia in utero affects growth from birth to late childhood dependent on child’s sex and severity of exposure: Follow-up of a nested case-control study.”. 2017. Accessed 17 April 2018. ↩