The risk of stroke during normal pregnancy is small. The greatest risk of hemorrhagic stroke occurs around the time of delivery. The hemorrhagic stroke can occur if your blood pressure has gotten too high. Another cause of hemorrhagic stroke in pregnancy can occur with normal blood pressure if you have a brain aneurysm. Some women are born with a brain aneurysm and may not know about it. These brain aneurysms can rupture during the pushing part of normal labor.
Occasionally a woman will have a brain aneurism that might rupture with normal blood pressure. These are tragic, catastrophic, and rare. The only way to know if a pregnant woman might have an aneurysm would be to take a CAT scan of every pregnant woman’s head and if an aneurysm is found, delivery the baby by C-section so she doesn’t die from pushing. With good reason, the American College of Obstetricians and Gynecologists (ACOG) has not recommended a CAT scan of every first-time mom because this condition is so rare. Thousands of women would need to be given an unnecessary CAT scan to find the one woman who needed it.
Sometimes pregnant women have an ischemic stroke, one caused by a clot or plaque closing an artery. This causes a lack of oxygen to the area supplied by this artery. An ischemic stroke is much less traumatic than a hemorrhagic stroke. In an ischemic stroke, the blood is shut off in a small area by a clot. This type of stroke is generally less destructive than a hemorrhagic stroke and the blockage can be opened.
Managing high blood pressure is the best way to prevent hemorrhagic strokes. The good news is that most hemorrhagic strokes can be avoided by giving apresoline (a kind of vasodilator), which lowers the blood pressure by relaxing the arteries. Apresoline tends to raise your heart rate, so propranolol is often also prescribed at the same time to control your heart rate.
Both the apresoline and the propranolol have been available for many years. They are effective, available, safe, and cheap medications. They are usually given at the time of delivery and not during pregnancy. If you have normal blood vessels, there is no excuse to die from a hemorrhagic hypertensive stroke at the time of delivery. Hypertensive hemorrhagic strokes seldom occur before labor.
Generally, apresoline and propranolol are not given during pregnancy. Hemorrhagic strokes are largely preventable by carefully watching your blood pressure and not letting it get too high. During pregnancy, Aldomet is generally used to lower blood pressure, which can help prevent pre-eclampsia. However, I believe there are some women who will develop pre-eclampsia even when their blood pressure is controlled during their pregnancy. My blog post on eclampsia provides more information about the importance of monitoring blood pressure in pregnancy.