General Consideration Intrapartum cardiovaseular changes 1. First-stage labor 300ml -500ml t(each contraction) Cardiac output t(maternal pain, anxiety) 2. Second-stage labor Lung circulation f(bearing-down efforts to expel the fetus) Venous return,(after fetus is deliveried) Placental circulation is lost(after placenta is deliveriedGeneral Consideration • Intrapartum cardiovascular changes 1. First-stage labor 300ml –500ml↑(each contraction) Cardiac output↑(maternal pain, anxiety) 2. Second-stage labor Lung circulation↑(bearing-down efforts to expel the fetus) Venous return↓(after fetus is deliveried) Placental circulation is lost (after placenta is deliveried)