Screening for Preeclampsia: US Preventive Services Task Force Recommendation Statement

Approximately 4% of pregnancies in the United States are affected by preeclampsia, defined as new-onset hypertension (or worsening hypertension in patients with existing hypertension) after 20 weeks' gestation, combined with either new-onset proteinuria or other symptoms involving multiple organ systems. This disorder is associated with poor maternal and fetal outcomes, including maternal mortality, maternal stroke, low birth weight, and stillbirth. African American women are affected by preeclampsia at a higher rate than are white women and also have higher fatality rates related to preeclampsia, which may be due to unequal access to adequate care. The US Preventative Services Task Force (USPSTF) accounts for both benefits and harms of preventive care services when making recommendations, but does not consider costs of services. After review of screening and diagnostic methods for preeclampsia, and accuracy and potential harms and benefits of those methods, the USPSTF aimed to update its recommendations on screening for preeclampsia. The USPSTF also reviewed evidence on the benefits and harms of treatment of screen-detected preeclampsia. The USPSTF found dipstick tests have a low accuracy for detecting proteinuria in pregnancy, whereas blood pressure measurements are accurate in screening for preeclampsia. It was found that well-established treatments of preeclampsia can substantially benefit the mother and child because it can reduce the risk of morbidity and mortality. The potential harm of screening and treatment is no greater than small. With moderate certainty, the USPSTF concludes that screening for preeclampsia carries a substantial net benefit and recommends screening for preeclampsia by obtaining blood pressure measurements at each prenatal care visit during pregnancy. Screening for preeclampsia with blood pressure measurement throughout pregnancy is recommended. To diagnose preeclampsia, the patient must have elevated blood pressure (>= 140/90 mm Hg on 2 occasions 4 hours apart after 20 weeks' gestation) and proteinuria or, in the absence of proteinuria, must have thrombocytopenia, renal insufficiency, impaired liver function, pulmonary edema, or cerebral or visual symptoms. After preeclampsia diagnosis, treatment may consist of antihypertensive medications, close fetal and maternal monitoring, and magnesium sulfate. In women with a high risk of preeclampsia, low-dose aspirin is also recommended as a preventive medication after 12 weeks' gestation.