VEGFA and preeclampsia: So far, studies investigated the alterations of VEGF/VEGFR and Ang/Tie2 expression on placenta from maternal smoking are seldom and limited to VEGF and VEGFR-1 on the assumption that maternal smoking is associated with a decreased risk of preeclampsia through reduced soluble form of VEGFR-1 which acts as a negative regulator of VEGF [14].