What is a cerebral embolism during pregnancy?
A cerebral embolism is the blockage of a blood vessel in the brain due to an embolus (a mass that has been traveling through the bloodstream), resulting in an embolic stroke. In medicine, a stroke is an acute (sudden) loss of function in the central nervous system, due to a problem with a blood vessel. Strokes are classified either as hemorrhagic (a blood vessel has ruptured), or ischemic, meaning that there is a shortage of blood supply to the tissues, due to blood vessel obstruction. Ischemic strokes are further categorized into thrombotic strokes (due to a blood clot, or thrombus, obstructing the vessel in the same place where the thrombus began) and embolic strokes.
Pregnant women can suffer different types of strokes, including cerebral embolism. Most commonly, the heart is the source of emboli that reach the brain, either because of heart surgery, problems with a valve on the left side of the heart (aortic valve and mitral valve), an infection of the inner layer of the heart (endocarditis), an aneurysm in the wall of the heart, or atrial fibrillation (AF) (quivering of the upper chambers of the heart without active pumping of the blood into the ventricles). Such emboli are more likely to form when a person is in a hypercoagulability state, meaning that her blood tends to form clots more easily than it should. Pregnancy is one condition that produces a hypercoagulability state. Cerebral embolism is a particular danger during the post-partum period, from delivery until about two weeks after delivery.
How common is cerebral embolism during pregnancy?
There have been a handful of epidemiological studies reporting stroke affecting up to 34 pregnant women per 100,000 deliveries. Still, it is difficult to state how common cerebral embolism is in terms of a precise number for a couple of reasons. First, the studies report on strokes overall during pregnancy, rather than separating cerebral embolism versus other stroke categories. This is because other types of strokes, such as hemorrhagic stroke (which is a danger particularly in pregnancy complications such as preeclampsia and eclampsia, featuring elevated blood pressure) and cerebral venous thrombosis (a type of thrombotic stroke in which a clot forms, not in an artery but in venous sinus (space) within the head). Second, the studies do not all use the same systems and criteria for classifying a condition as a stroke.
What is clear, on the other hand, is that the occurrence of strokes during pregnancy has been increasing during the past several years, possibly because older women are having children more than previously. Your risk of suffering an embolic stroke depends on a range of risk factors. Emboli that reach the brain also can form in aneurysms and other blood vessel abnormalities (such as entities called arteriovenous malformations) along routes between the heart and brain, plus certain genetic conditions, such as sickle cell disease, entail an elevated risk for emboli. Additionally, in many people, emboli generated on the right side of the heart and in veins (venous thromboembolism) can reach the left side of the heart through what is called a patent foramen ovale (PFO), an opening between the hearts right and left atria. The foramen ovale is present in everybody during fetal life and closes soon after birth, but possibly as many as one-third of all people have a PFO. Additionally, there is a severe pregnancy complication called an amniotic fluid embolism (AFE). AFE is not only an embolism because it produces an immune response to amniotic material in the mothers bloodstream, but it can also lead to a cerebral embolism.
How is cerebral embolism during pregnancy diagnosed?
The physical examination conducted by your doctor will include a neurological exam that will provide clues as to the location of the cerebral embolism. Definitive diagnosis depends on either computed tomography (CT) scanning or magnetic resonance imaging (MRI) of the brain, plus doctors also may order a cerebral angiogram, which involves a catheter inserted through a small incision into an artery in your neck. Additional tests may include carotid ultrasound that provides images of the inside of your carotid arteries. You can be given an echocardiogram to find a location in the heart that may be generating emboli. The workup will also include an electrocardiogram (ECG), which can be helpful in diagnosis if a cardiac condition, such as AF, is the reason for the embolism.
Does cerebral embolism cause problems during pregnancy?
Yes. Cerebral embolism can produce temporary or permanent disability and even can be fatal. Disabilities that often occur in strokes include problems with speech or understanding of speech, and paralysis of particular parts of the body, such as the face, arms, or legs. Typically, one side of the body or face is affected.
Does cerebral embolism cause problems for the baby?
Yes, because it threatens the mothers life and ability to function.
What to consider about taking medications when you are pregnant or breastfeeding:
- The risks to yourself and your baby if you do not treat the cerebral embolism
- The risks and benefits of each medication you use when you are pregnant
- The risks and benefits of each medication you use when you are breastfeeding
What should I know about using medication to treat cerebral embolism during pregnancy?
Medications are given to restore blood flow to the affected area of the brain and to prevent additional emboli from forming and reaching the brain. Quick recognition of the stroke is extremely important and is a major factor in determining the treatment. The gold standard treatment consists of drugs of a category called fibrinolytic (or thrombolytic) agents, which are given to break up the clot. In particular, a clot-busting agent called tissue plasminogen activator (tPA) is given. Still, it is effective only if you receive it within approximately 4.5 hours of the onset of the stroke. The drug can be given intravenously, or endovascularly, meaning through an instrument in a catheter that is inserted into a vein. Although tPA is considered to be a risk for the fetus, it has been administered successfully in pregnancy, and the risk must be weighed against the risks and benefits of giving the drug and the risk of not giving it.
As for preventing more emboli, this goal is achieved using blood thinner medications, such as warfarin (and newer drugs that have similar functions) or heparin and antiplatelet therapy, such as aspirin. The danger of warfarin is a huge issue in pregnancy. Still, its a complex issue because warfarin is dangerous to the baby only at particular times during pregnancy and often is the drug of choice when the mother has a very severe clotting problem. Sometimes it is best to avoid warfarin for the entire pregnancy while giving the mother low molecular weight heparin (LMWH) or unfractionated heparin (UFH). Other times, doctors prefer to avoid heparin during the first trimester, then resume warfarin in the second trimester, and th
en switch back to heparin in the last weeks of pregnancy. Aspirin, which also reduces clotting but by inhibiting the clotting cells called platelets is useful in certain cases and is safe for most of the pregnancy.
Who should NOT stop taking medication for cerebral embolism during pregnancy?
If you have a cerebral embolism during pregnancy, taking the medication is a matter of life and death, so no one should stop taking the medication until it is ended by the order of your physician.
What should I know about choosing a medication for my cerebral embolism during pregnancy?
It is important to stay in communication with your health care provider as the release of new studies over time can change the outlook on the role of specific medications during pregnancy.
You may find Pregistrys expert reports about the medications to treat this condition here. Additional information can also be found in the sources listed below.
What should I know about taking a medication for my cerebral embolism when I am breastfeeding?
There is some concern about aspirin because it enters breastmilk, but it enters in very tiny amounts. Neither UFH nor LMWH is thought to be harmful in breastfeeding, but after a stroke, you are likely to be on various medications, some of which may require you to avoid breastfeeding. Neither warfarin (used in North American for long-term anticoagulation therapy) nor a similar drug called acenocoumarol (used in Europe) enter breastmilk or otherwise affect a nursing infant. Thus, once you have delivered, warfarin therapy can be added or added back.
What alternative therapies besides medications can I use to treat my cerebral embolism during pregnancy?
Discussion about alternatives involves not whether to give medications, but how to deliver them, other therapies to provide to make the medications work better, and what procedures to perform. While clot-busting medications such as tPA are effective if given within 4.5 hours of the onset of stroke symptoms, researchers are investigating whether and how endovascular delivery of the drugs can improve the effectiveness. A procedure known as mechanical thrombectomy, in which endovascular techniques are used to remove the clot from the blood vessel, can be effective up to 24 hours after the stroke symptoms have begun. Additionally, some stroke centers have the capability to cool down your body, and especially your brain, ever more rapidly. Known as therapeutic hypothermia, this procedure is showing effectiveness in improving stroke recovery. Still, generally, it is performed only by specialized groups of doctors who are researching it (this is likely to change in the years to come). As with the other treatments, hypothermia must be initiated very early.
What can I do for myself and my baby when I have cerebral embolism during pregnancy?
It is very important to follow the instructions of your physician.
Resources for cerebral embolism in pregnancy:
For more information about cerebral embolism during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or contact the following organizations: