Worldwide, 5-8% of pregnant women are diagnosed with preeclampsia. This disease increases the morbidity and mortality of the fetus and pregnant woman, especially in developing countries. Preeclampsia is characterized by systolic blood pressure ] 140mmHg or diastolic blood pressure] 90mmHg as measured twice, and 24 h proteinuria �0.3 g, after 20 weeks of gestation. The cause of preeclampsia is still incompletely elucidated. Numerous studies have suggested to modernize the definition of preeclampsia by incorporating key biomarkers of either placental or vascular origins, including placental growth factor (PIGF) and antiangiogenic factors such as tyrosine kinase-1 (sFlt-1) in the diagnosis of preeclampsia and the risk of occurrence of the disease in the second trimester of pregnancy [1-5]. We studied a group of 50 patients with a 21-week pregnancy diagnosis, we calculated the ratio between sFlt-1 and PIGF and we tested to see if there was an association between this ratio and the resistivity index (IR) of the uterine artery using the artery Doppler ultrasound. The PIGF level in our group was decreased in women who developed preeclampsia compared to the control group where this problem did not occur. Doppler ultrasound examination during the second trimester of pregnancy may provide extra data for prediction of preeclampsia. Although much of pathophysiology of preeclampsia has been explained, the exact etiology of this disorder remains unclear. It is certain that before the clinical signs of preeclampsia are detectable, there is an imbalance between pro-angiogenic and anti-angiogenic factors.