Risk factors for multiple pregnancy include Ovarian stimulation (usually with clomiphene or gonadotropins) Assisted reproduction (eg, in vitro fertilization) Prior multifetal pregnancy Advanced maternal age West African descent Complications Multifetal pregnancy increases the risk of Preeclampsia Gestational diabetes Postpartum hemorrhage Cesarean delivery Preterm delivery Growth restriction Stillbirth Neonatal death, largely due to prematurity Postpartum depression The overdistended uterus tends to stimulate preterm labor, causing preterm delivery.