Acute Evidence Tables 2 Diagnostic Imaging
Initial Emergency Management
While stroke during pregnancy presents several additional challenges, initial emergency investigations and treatment of stroke during pregnancy, or within the 6 weeks thereafter, is similar to treatment in the nonpregnancy state. Rapid presentation to a stroke centre for timely assessment and management represents the best opportunity for a good outcome for the mother and baby. Delay or deferral of critical steps in the diagnosis of stroke, and life-saving care due to pregnancy is not warranted. In such cases, maternal health is essential for fetal well-being. Hypertension and headaches, which are both common during pregnancy, may also indicate more serious conditions. In particular, the rapid identification and treatment of hypertension in a woman presenting with neurological symptoms with a history of preeclampsia, is of critical importance. Hypertensive treatment should be initiated to achieve and maintain a systolic blood pressure of <160 mm Hg. It should be noted that women with severe preeclampsia and eclampsia do not always present with elevations in diastolic blood pressure (Martin et al. 2005). While common during pregnancy and often benign, headaches may also occur as the result of more serious neurological conditions. Their history and characteristics should be queried. Thunderclap headache may be a symptom of subarachnoid hemorrhage, while a headache with atypical aura, may result from a stroke or TIA. Headache will accompany ischemic stroke in 17% to 34% of cases and are usually nonspecific in quality and of moderate intensity. (MacGregor et al. 2014).
Many pregnant women and their care providers are concerned about the fetal risk associated with neuroimaging and ionizing radiation. However, given the severe maternal risk caused by potential delay in diagnosis of stroke (Yoshimatsu et al. 2004) and the small risk to the fetus of computed tomography, neuroimaging with CT scan without first confirming a pregnancy is acceptable. In fact, the fetal radiation dose associated with head or neck CT is considered very low (0.001 to 0.01 mGy) (AROC 2017). Most estimates suggest that fetal radiation doses of <50 mGY have negligible risk of fetal malformation, abortions or other pregnancy complications when compared to the general risk of pregnancy (McCollough CH et al. 2007; Tirada et al. 2015). Likewise, magnetic resonance imaging (MRI) is considered safe at 3.0