It is associated with a higher risk of preterm delivery, vaginal bleeding during pregnancy, subchorionic hematoma, preterm premature rupture of membranes, placental insufficiency and placental abruption, especially when maternal serum alpha-fetoprotein is elevated (1.4 MoM) (multiple of the median) and when UtA-PI (uterine artery-pulsatility index) of 1.2 [27,32,33,34]. This evidence concerns the gene AFP and placental abruption.