Preeclampsia is a complication of pregnancy in which a woman develops high blood pressure, high levels of protein in the urine, and other symptoms. It occurs during the second half of pregnancy, after 20 weeks of gestation. Although there are certain risk factors that make preeclampsia more likely in some women, any pregnant woman can develop preeclampsia.
Preeclampsia can lead to organ damage throughout the body. The most commonly affected organs are the kidneys and liver, but other organs can also be affected. Women who experience preeclampsia during their pregnancy can have serious and lasting health consequences, and can even die as a result of this condition.
Treating preeclampsia can be challenging. When possible, doctors may recommend delivering the baby early, to reduce the risk of significant harm to the mother. However, preeclampsia sometimes develops too early in pregnancy for a baby to be delivered safely. There are also rare cases of women developing postpartum preeclampsia, which occurs after the mother has already given birth.
What is the main cause of preeclampsia?
According to the Mayo Clinic, it’s believed that preeclampsia is caused by abnormal development of the placenta. This is the organ that provides nourishment for the growing fetus during gestation. Early in a woman’s pregnancy, her body generates new blood vessels, which become a part of the placenta. Nutrients and oxygen from the mother’s blood will cross the placenta into the baby’s blood, allowing the baby to develop and grow.
In some women, these new blood vessels don’t develop properly. They’re too narrow, and don’t react properly to hormonal signaling. This reduces the ability of these vessels to deliver adequate blood to the placenta.
It’s still not known exactly what causes some women to develop preeclampsia while others do not. Some of the possible factors that lead to the abnormal blood vessel development may include:
- Damage to blood vessels
- Specific genes
- Immune system problems
- Not enough blood flow to the uterus
In many cases, preeclampsia may be multifactorial, meaning that more than one factor is involved in the development of the condition.
What are the risk factors for preeclampsia?
There are certain risk factors that increase a woman’s likelihood of developing preeclampsia. Some of these include:
- Family history of preeclampsia, or a previous personal history of preeclampsia
- First pregnancy
- Chronic hypertension
- Age, as being very young or over 35 both raise the preeclampsia risk
- Race, with black women having a higher risk
- New paternity
- Carrying multiples (twins, triplets, etc.)
- Interval between pregnancies (closer than two years or more than 10 years apart creates additional risk)
- In vitro fertilization
According to the Preeclampsia Foundation, It’s important to note that having multiple risk factors doesn’t mean that a woman is certain to develop preeclampsia, and a lack of risk factors doesn’t mean that a woman is entirely safe from it. However, those who have more risk factors may be monitored more closely by their doctors, to detect preeclampsia as early as possible if it does develop.
What are the signs of preeclampsia?
Preeclampsia often doesn’t cause any obvious symptoms in its early stages. This is why regular prenatal care is crucial to protect the health of both mother and baby. Without routine monitoring for preeclampsia, organ damage or other health risks may occur before the mother realizes there’s a problem. In addition to monitoring by their doctor, women at higher risk may choose to take blood pressure readings at home, so they can let their doctor know right away if their blood pressure starts to rise.
Women with preeclampsia have high blood pressure, along with one or more of the following signs:
- Severe headaches
- Excess protein in the urine
- Decreased output of urine
- Nausea and vomiting
- Upper abdominal pain, especially on the right side under the ribs
- Impaired liver function
- Decreased platelet levels in the blood
- Fluid in the lungs, causing shortness of breath
- Vision changes, such as blurry vision, light sensitivity, or temporary loss of vision
Pregnant women who are experiencing any of these symptoms should see their doctor right away. If they are found to have preeclampsia, they will need to work with their doctor on a treatment plan that can reduce the risk of serious health problems in both mother and baby.
How is preeclampsia diagnosed?
The diagnosis of preeclampsia is made when two conditions are present:
- The mother has high blood pressure, which developed after 20 weeks of gestation.
- There is damage to at least one organ system in the body. The most commonly affected organs are the kidneys, liver, and nervous system.
Besides monitoring the mother’s blood pressure, doctors also use blood tests and urine tests to check the function of various organ systems. These tests should be performed regularly throughout pregnancy, at a woman’s prenatal care appointments. If a woman develops any unusual symptoms, she should check in with her doctor, in case these could indicate preeclampsia.
Some women develop high blood pressure during pregnancy, but without any signs of damage to organ systems. This is known as gestational hypertension. It may or may not develop into preeclampsia as the pregnancy progresses.
There are also some women who already had high blood pressure before the pregnancy. This is known as chronic hypertension. Women with this condition can also develop preeclampsia; this is known as chronic hypertension with superimposed preeclampsia, and involves worsening high blood pressure along with damage to organ systems.
What are the effects and complications of preeclampsia?
Preeclampsia affects many systems in the mother’s body and can also have serious effects on the baby. Some of the possible complications of preeclampsia include:
- Hemolysis (destruction of red blood cells), leading to anemia (low red blood cell count)
- Low platelet count, which leads to an increased risk of bleeding
- Damage to the liver
- Eclampsia, in which the mother has seizures or goes into a coma
- Strokes or other forms of brain damage
- Fetal growth restriction, in which the baby grows too slowly because of inadequate blood flow through the placenta
- Placental abruption, in which the placenta pulls away from the uterine wall, creating a risk of severe bleeding that can be life-threatening
Regular prenatal care is essential to monitor pregnant women for signs of preeclampsia, so that it can be addressed early if it develops. This includes monitoring the mother’s vital signs (such as blood pressure and heart rate) as well as the baby’s heart rate and growth. Regular blood tests and urine tests are used to check whether the mother’s organ systems are functioning normally.
If there are any signs of preeclampsia, then the frequency of prenatal appointments may be increased, to monitor both mother and baby more closely. Women who are at higher risk for preeclampsia may also be monitored more frequently.
How is preeclampsia treated?
According to the Mayo Clinic, the best treatment option for preeclampsia is delivery of the baby. Because pregnant women with preeclampsia are at significant risk of serious health problems, ending the pregnancy by giving birth is the most reliable way to protect them from serious medical complications.
The primary medical decision that needs to be made is when it’s time to deliver the baby. To make this choice, doctors weigh the risks that early delivery can present to the baby’s health against the damage that preeclampsia is causing to the health of both mother and baby. Delivering a baby before 37 weeks of gestation does create a risk for the baby, but when preeclampsia is severe enough, then there may be a greater risk to both baby and mother from continuing the pregnancy.
If the baby is close to being ready for delivery, doctors may give corticosteroids to help the baby’s lungs to mature. The lungs are the last system to be ready for birth, so using these medications may help to make an early delivery safer for the baby.
- Blood pressure medication, which can help to reduce the risk of organ damage by lowering the mother’s blood pressure.
- Anticonvulsant medications, which may be used to try to prevent seizures. If seizures do occur, delivery becomes necessary no matter how far along in the pregnancy a woman might be.
- Corticosteroids, which may help to improve the mother’s liver functions and platelet count. This can help her carry the pregnancy longer with lower risk.