The risk for stroke during pregnancy is fairly low ( about 34 per 100 000 deliveries ), but risk is highest in the postpartum period. Although the traditional definition of a postpartum time frame is 6 weeks, a recent study showed that thrombotic events may occur up to 12 weeks after birth. Suspicion for a postpartum stroke or vasculopathy ( the posterior reversible encephalopathy syndrome or the reversible cerebral vasoconstriction syndrome ) or cerebral venous thrombosis should be heightened for women who develop new-onset headache, blurred vision, or seizures or any new neurologic signs or symptoms during the postpartum period.
Preeclampsia and eclampsia
Preeclampsia occurs in approximately 5% of pregnancies. It is defined as high blood pressure in pregnancy associated with proteinuria ( urinary protein excretion greater than or equal to 300 mg/24 h ) or thrombocytopenia, impaired liver function, progressive renal insufficiency, pulmonary edema, or new-onset cerebral or visual disturbances.
The American Congress of Obstetricians and Gynecologists ( formerly the American College of Obstetricians and Gynecologists ) published an updated guideline that changed the criteria for preeclampsia to include women without proteinuria if one of the other multisystem features is present.
Because of evidence that a history of preeclampsia is associated with a 2-fold risk for stroke and a 4-fold risk for hypertension later in life, we recommend documenting preeclampsia as a risk factor ( class IIa; level of evidence C ). The intent is to increase awareness that women with a history of preeclampsia would probably benefit from lifestyle change and early assessment of cardiovascular risk and interventions. Although the evidence for an association between preeclampsia and later hypertension with attendant risk for stroke is clear, the current gap in knowledge is identifying which women with preeclampsia will have these complications. More research is needed to understand biomarkers or other characteristics that might identify the women at highest risk.
Moderate hypertension in pregnancy
Another new recommendation is to consider treating women with a systolic blood pressure between 150 and 159 mm Hg or a diastolic blood pressure between 100 and 109 mm Hg of new onset during pregnancy ( class IIa; level of evidence B ). This recommendation differs from that of the guideline of the American Congress of Obstetricians and Gynecologists, which recommends only treating patients with a blood pressure greater than 160/110 mm Hg.
The new recommendation is based on evidence that treatment of mild to moderately elevated blood pressure in pregnancy is associated with a 50% reduction in risk for severe hypertension ( relative risk, RR=0.5 ).
New studies or reanalyses of existing data using the new definition of preeclampsia would be useful to assess the benefit of treating mild to moderately elevated blood pressure during pregnancy.
Although safe and effective antihypertensive medications can be used during pregnancy, risk to the fetus must also be considered. ( Xagena )
Bushnell C, McCullough L, Ann Intern Med 2014;160:853-857