17.15: Autotransfusion

During labor, the uterus undergoes powerful contractions, leading to the displacement of blood into circulation. In the first stage of labor, there is a notable increase in cardiac output, rising by approximately 20 percent. As labor progresses to the second stage, characterized by the delivery of the baby, the cardiac output experiences a more substantial surge, elevating by around 50 percent. Following the delivery of the placenta, there is a remarkable spike in cardiac output, reaching up to 80 percent above prelabor levels. However, this heightened cardiac output is a transient phenomenon, as it gradually returns to prelabor levels within 48 hours and eventually stabilizes at pre pregnancy levels within 12 to 24 weeks postpartum. These dynamic changes in cardiac output during labor are integral components of the physiological adaptations that support the birthing process.

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