Rana et al Angiogenic Factors and Preeclampsia 199 including those who remain normotensive. 4, 15 These factors combined with the above discussed physiological increments in protein excretion make it more difficult to discriminate preeclampsia from controls using angiogenic factor measurements when the disease presents near term. However, beyond gestational week 37, such testing seems unnecessary as then hypertension, whatever the cause, is considered by most as sufficient reason to deliver. 34 One argument against pursuing biomarker research has been the absence of disease-modifying agents to make such pursuits useful. Critics argue that angiogenic profile use differs from those for biomarkers measured to predict aneuploidy or diabetes mellitus where pregnancy can be terminated or blood glucose controlled. It is therefore imperative that studies to predict preeclampsia focus not only on identifying the disease, but also demonstrate clinical usefulness, that is, what does the obstetrician do if disease is predicted early? Finally, most studies using angiogenic factors were performed with manual ELISA kits, methodology often displaying high interassay coefficient of variation (10%–20%). Automated assays, now available, are much more reliable,(interassay coefficients of variation< 5%), report the results rapidly, and produce more robust associations with altered factor levels and preeclampsia. 35–37