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Placenta Previa
“afterbirth before birth” placenta is first
Incidence is 1 in 300 deliveries. Incidence increases significantly with history of a c/s and
also increases with the number of c/s
Up to 1000mL of blood flows through the placenta every minute at term. There is
potential for significant blood loss.
Route of delivery is c/s
Never perform vaginal exam when vaginal bleeding is present until an u/s is done to
determine placental location b/c it can cause dislodgment of the placenta causing
hemorrhage
Four classifications of placenta previa:
Total placental previa: The placenta completely covers the cervical os
Partial placenta previa: Placenta partially covers the cervical os
Marginal placenta previa: The placenta is at the margin of the cervical os
Low-lying placenta: The placenta is implanted in the lower uterine segment in close
proximity to the cervical os
Risk Factors:
Cause is unknown
Endometrial scarring
-previous placenta previa
-prior cesarean section
Placenta Previa
“afterbirth before birth” placenta is first
Incidence is 1 in 300 deliveries. Incidence increases significantly with history of a c/s and
also increases with the number of c/s
Up to 1000mL of blood flows through the placenta every minute at term. There is
potential for significant blood loss.
Route of delivery is c/s
Never perform vaginal exam when vaginal bleeding is present until an u/s is done to
determine placental location b/c it can cause dislodgment of the placenta causing
hemorrhage
Four classifications of placenta previa:
Total placental previa: The placenta completely covers the cervical os
Partial placenta previa: Placenta partially covers the cervical os
Marginal placenta previa: The placenta is at the margin of the cervical os
Low-lying placenta: The placenta is implanted in the lower uterine segment in close
proximity to the cervical os
Risk Factors:
Cause is unknown
Endometrial scarring
-previous placenta previa
-prior cesarean section
