The present invention provides methods and compositions related to the detection and/or monitoring of the levels of angiogenic factors, specifically VEGF, PlGF and sFlt-1, in urine samples obtained from pregnant women and the effects of such levels on the risk of developing complications of pregnancy, including hypertensive disorders such as preeclampsia, in the first, second, and/or third trimester of pregnancy. The present invention also provides kits for identifying and screening patients at risk of developing a complication of pregnancy, such as preeclampsia.