Clonus is a rhythmic movement of your ankle and foot during pregnancy. It’s often an early symptom of severe preeclampsia and a medical emergency.

Clonus, a rhythmic movement of your foot and ankle, is an early symptom of neurologic conditions. If you have clonus during pregnancy, it usually means you have severe preeclampsia, a serious medical condition related to high blood pressure. Severe preeclampsia is a medical emergency.

Here’s what you need to know about clonus during pregnancy and what to expect if you have it.

Clonus is a neurological symptom usually affecting your ankle and foot. It’s a rhythmic movement that continues after tapping and stroking your lower leg.

Testing for clonus is a routine part of a neurological exam because having clonus is one sign of the presence of a neurological condition.

When clonus occurs during pregnancy, it’s a symptom of a medical condition called severe preeclampsia, which may quickly become a medical emergency.

It also means you’re at a high risk of having seizures.

Other symptoms of severe preeclampsia include:

Doctors help treat clonus during pregnancy by treating the underlying condition. The main reason you might have clonus is severe preeclampsia.

The primary treatment for preeclampsia is delivering your baby — even if it’s before your due date or early in your pregnancy. Other treatment options include the medication magnesium sulfate, which helps lower the risk of seizures during pregnancy. You may need this medication if doctors try to delay delivery so your baby can grow more.

Other treatment options include medications to lower your blood pressure and corticosteroids to help your baby’s lungs mature faster.

If you have clonus during pregnancy, you may need further medical follow-up and treatment.

Your exact outlook depends on the underlying cause of your clonus. If you have preeclampsia, you may deliver your baby earlier than expected. Having preeclampsia can also affect your baby in the following ways:

Does preeclampsia cause clonus?

Having clonus is a sign you may also have preeclampsia. The same underlying conditions that cause preeclampsia also cause clonus — like high blood pressure and edema.

What are the neurological symptoms of preeclampsia?

In addition to clonus, other neurological symptoms of preeclampsia include:

Clonus during pregnancy is serious. It’s often a sign that you have severe preeclampsia and may soon have seizures.

Having clonus during pregnancy generally means your pregnancy is high risk, and you may deliver your baby earlier than expected. You may need additional follow-up and treatment with healthcare professionals.