Pregnancy and the postpartum
period are associated with an increased risk of ischemic stroke and cerebral hemorrhage. Labor/delivery and postpartum appear to be the periods of highest risk, with 90% of events occurring at these times.1,2 The incidence appears to be increasing, with stroke causing about 5% of maternal deaths in the United States.3 Appropriate prenatal and obstetric care can detect risks and decrease the incidence of most common forms of stroke. Rapid diagnosis and intervention is often critical for decreasing death and morbidity.
Explore This IssueACEP News: Vol 31 – No 02 – February 2012
Risk factors for stroke in pregnancy are the same as in the nonpregnant population but may be increased in pregnancy by pro-coagulation changes, hypertension, and increased vascular constrictive reactivity. These latter changes are often associated with pre-eclampsia or eclampsia.
Standard risk factors for stroke include:
- Aura-associated migraine headaches: Vasospasm then vasodilatation in cerebral vessels are reported to be significant problems in about 2/1,000 pregnancies. Women with these types of migraines in pregnancy may have up to 15 times increased risk for stroke.
- Increased maternal age.
- Chronic hypertension.
- Substance abuse, including cocaine, methamphetamine, and tobacco.
- Intracranial vascular abnormalities, including arteriovenous malformations (AVMs) and aneurysms.
- Congenital or acquired thrombophilias, which can promote arterial or venous thrombosis.
- Cardiac or vascular pathology, which can cause arterial embolic, injury/dissection, or occlusion.
- Other conditions that can cause vascular injury or obstruction (such as sickle cell disease, syphilis infection, polycythemia vera, vasculitis).
Always consider pre-eclampsia/eclampsia as an underlying factor in patients at more than 20 weeks gestation. Postpartum angiopathy presents with a similar clinical picture as subarachnoid hemorrhage (SAH). This most often occurs in the first week post partum and is caused by reversible cerebral vasoconstriction.4
Dural sinus thrombosis is related to an increase in circulating clotting factors during pregnancy and relative dehydration occurring during delivery and postpartum. A case has been reported 3 months post partum.5 Headache is highly variable. Associated signs and symptoms can include seizures, paresis, or focal neurologic deficits, papilledema, altered mental status, and increased isolated intracranial hypertension. Risk factors include genetic hypercoagulability, advanced maternal age, hyperemesis, cesarean delivery, infection, and maternal hypertension.6
For patients who are candidates for treatment with IV tissue plasminogen activator (TPA), the goal is to complete a head CT scan without contrast within 25 minutes of ED arrival, with the study interpreted within another 20 minutes (door-to-interpretation time of 45 minutes).7 Radiation from this study does not put the fetus at risk.