Placental hypoperfusion

After 5 months of pregnancy, the uterus grows larger. When you lie supine, the uterus compresses the blood vessels in front of the spine, which reduces the amount of blood discharged from the heart, and the perfusion of the uterine placenta is correspondingly reduced. If the abdominal aorta is compressed, the uterine placental blood flow is directly reduced. Insufficient long-term placental perfusion and fetal hypoxia can lead to intrauterine growth retardation. Acute and severe placental perfusion can cause fetal distress.