Preeclampsia is a complication some women experience in pregnancy. It often occurs after 20 weeks of pregnancy, but rarely can develop earlier or postpartum. The major signs of preeclampsia are high blood pressure and certain organs not working normally. A possible sign is excess protein in urine.

The exact cause of preeclampsia is unknown. Experts think it’s caused by problems with the blood vessels that connect the placenta, the organ that passes oxygen from mom to baby, to the uterus.

During the early stages of pregnancy, new blood vessels begin to form between the placenta and uterine wall. These new blood vessels may develop abnormally for several reasons, including:

  • inadequate blood flow to the uterus
  • blood vessel damage
  • immune system problems
  • genetic factors

These abnormal blood vessels restrict the amount of blood that can move to the placenta. This dysfunction can cause a pregnant woman’s blood pressure to increase.

If left untreated, preeclampsia can be life-threatening. Because it involves problems with the placenta, the recommended treatment for preeclampsia is delivery of the baby and placenta. The risks and benefits regarding timing of delivery are based on the severity of the disease.

A diagnosis of preeclampsia early in your pregnancy can be tricky. The baby needs time to grow, but you both need to avoid serious complications. In this case, your doctor may prescribe magnesium sulfate as well as medications to help reduce blood pressure.

Magnesium sulfate therapy is used to prevent seizures in women with preeclampsia. It can also help prolong a pregnancy for up to two days. This allows drugs that speed up your baby’s lung development to be administered.

In some women, preeclampsia develops gradually without any symptoms.

High blood pressure, the major sign of preeclampsia, usually occurs suddenly. This is why it’s important for pregnant women to monitor their blood pressure closely, especially later in their pregnancy. A blood pressure reading of 140/90 mm Hg or higher, taken at two separate times at least four hours apart, is considered abnormal.

Besides high blood pressure, other signs or symptoms of preeclampsia include:

  • excess protein in urine
  • decreased amount of urine
  • low platelet count in blood
  • intense headaches
  • vision problems such as loss of vision, blurry vision, and sensitivity to light
  • pain in the upper abdomen, usually under the ribs on the right side
  • vomiting or nausea
  • abnormal liver function
  • trouble breathing due to fluid in the lungs
  • rapid weight gain and swelling, especially in the face and hands

If your doctor suspects preeclampsia, they’ll perform blood and urine tests to make a diagnosis.

You’re more likely to have complications if you develop preeclampsia early in pregnancy. In some cases, doctors must perform induced labor or a caesarean delivery to remove the baby. This will stop preeclampsia from progressing and should lead to resolution of the condition.

If left untreated, complications may develop. Some complications of preeclampsia include:

  • a lack of oxygen to the placenta which can cause slow growth, low birth weight, or preterm birth of the baby or even stillbirth
  • placental abruption, or the separation of the placenta from the uterus wall, which can cause severe bleeding and damage to the placenta
  • HELLP syndrome, which causes loss of red blood cells, elevated liver enzymes, and low blood platelet count, resulting in organ damage
  • eclampsia, which is preeclampsia with seizures
  • stroke, which can lead to permanent brain damage or even death

Women who develop preeclampsia face an increased risk for heart and blood vessel disease. Their risk of preeclampsia in future pregnancies also increases. Women who’ve had preeclampsia have a 16 percent chance of developing it again in a future pregnancy.

The only treatment to stop progression and lead to resolution of preeclampsia is delivery of the baby and placenta. Waiting to deliver can increase risk of complications but delivering too early in the pregnancy increases the risk for preterm birth.

If it’s too early in your pregnancy, you may be told to wait until the baby is mature enough to be born to minimize those risks.

Depending on the severity of the disease and gestational age, doctors may recommend women with preeclampsia come in more often for outpatient prenatal visits, or possibly be admitted to the hospital. They’ll likely perform more frequent blood and urine tests. They may also prescribe:

  • medications to lower blood pressure
  • corticosteroids to help mature the baby’s lungs and improve the mother’s health

In severe cases of preeclampsia, doctors often recommend antiseizure medications, such as magnesium sulfate. Magnesium sulfate is a mineral that reduces seizure risks in women with preeclampsia. A healthcare provider will give the medication intravenously.

Sometimes, it’s also used to prolong pregnancy for up to two days. This allows time for corticosteroid drugs to improve the baby’s lung function.

Magnesium sulfate usually takes effect immediately. It’s normally given until about 24 hours after delivery of the baby. Women receiving magnesium sulfate are hospitalized for close monitoring of the treatment.

Magnesium sulfate can be beneficial to some with preeclampsia. But there’s a risk of magnesium overdose, called magnesium toxicity. Taking too much magnesium can be life-threatening to both mother and child. In women, the most common symptoms include:

  • nausea, diarrhea, or vomiting
  • large drops in blood pressure
  • slow or irregular heart rate
  • breathing problems
  • deficiencies in minerals other than magnesium, especially calcium
  • confusion or fogginess
  • coma
  • heart attack
  • kidney damage

In a baby, magnesium toxicity can cause low muscle tone. This is caused by poor muscle control and low bone density. These conditions can put a baby at greater risk for injuries, such as bone fractures, and even death.

Doctors treat magnesium toxicity with:

  • giving an antidote
  • fluids
  • breathing support
  • dialysis

To prevent magnesium toxicity from happening in the first place, your doctor should closely monitor your intake. They may also ask how you’re feeling, monitor your breathing, and check your reflexes often.

The risk of toxicity from magnesium sulfate is low if you’re dosed appropriately and have normal kidney function.

If you have preeclampsia, your doctor may continue to give you magnesium sulfate throughout your delivery. Your blood pressure should return to a normal level within days to weeks of delivery. Because the condition may not resolve immediately, close follow up after delivery and for some time after is important.

The best way to prevent complications from preeclampsia is an early diagnosis. When you go to your prenatal care visits, always tell your doctor about any new symptoms.