First trimester placental growth factor and soluble fms-like tyrosine kinase 1 and risk for preeclampsia. - Thadhani,R.; Mutter,W.P.; Wolf,M.; Levine,R.J.; Taylor,R.N.; Sukhatme,V.P.; Ecker,J.; Karumanchi,S.A. (J Clin Endocrinol Metab, 2004)