Although their levels are similar between second-trimester and term controls, UPR signaling (p-eIF2α, eIF2α, XBP-1 and GRP78) increases significantly in spontaneous preterm placentas delivered vaginally for acute chorioamnionitis and other conditions such as sub-chorionic and intra-parenchymal hemorrhage [164]. The gene discussed is EIF2A; the disease is hemorrhage.