上海交通大学医学院：《妇产科学》（双语） 17 PLACENTA PREVIA

PLACENTA PREVIA Lin Qi De

PLACENTA PREVIA Lin Qi De

Definition Placenta previa: Abnormal location of the placenta over or in close proximity to the internal os Incidence: approximately 1 /250 pregnancy **: nulliparas: 1 /1000 1/1500 pregnancy d: grandmultiparas: 1/20

Definition Placenta previa: Abnormal location of the placenta over ,or in close proximity to the internal os. Incidence: approximately 1 /250 pregnancy nulliparas: 1/1000~1/1500 pregnancy grandmultiparas: 1/20

Classification Complete(total) placenta previa: entire cervical os is covered Partial placenta previa: the margin of the placenta extends across but not all of the internal oS Marginal: edge of the placenta lies adjacent to the internal os Low lying placenta: placenta is located near but not directly adjacent to the internal OS

Classification Complete (total) placenta previa: entire cervical os is covered Partial placenta previa:the margin of the placenta extends across but not all of the internal os. Marginal:edge of the placenta lies adjacent to the internal os Low lying placenta:placenta is located near but not directly adjacent to the internal os

Etiology Mechanism: abnormal vascularization Predisposing factors: .Twin pregnancy increasing maternal age iNcreasing parity Previous cesarean section

Etiology Mechanism: abnormal vascularization Predisposing factors: •Twin pregnancy •Increasing maternal age •Increasing parity •Previous cesarean section

diagnosis Painless vaginal bleed first bleeding episode is 29N30 weeks Ultrasonography benefit in localizing the placenta and diagnosis placenta previa

diagnosis Painless vaginal bleed: first bleeding episode is 29~30 weeks Ultrasonography: benefit in localizing the placenta and diagnosis placenta previa

Caution Double setup vaginal examination No digital vaginal or rectal examination is preformed in case of placenta previa. only as a final and definitive event and only under conditions of double set up This procedure involves careful evaluation of the cervix in the operation room with full preparations for rapid cesarean section

Caution Double setup vaginal examination No digital vaginal or rectal examination is preformed in case of placenta previa . Only as a final and definitive event and only under conditions of double set up. This procedure involves careful evaluation of the cervix in the operation room with full preparations for rapid cesarean section

Management Basic management iNitial hospitalization with hemodynamic stabilization ● nforced bed rest Restrictions of activity

Management Basic management •Initial hospitalization with hemodynamic stabilization •Enforced bed rest •Restrictions of activity

Expectant management (allow for further fetal growth and maturation .Blood transfusion is given as necessary . Amniocentesis for fetal lung maturity testing Cesarean birth if fetus is thought to be mature

Expectant management (allow for further fetal growth and maturation) •Blood transfusion is given as necessary •Amniocentesis for fetal lung maturity testing •Cesarean birth if fetus is thought to be mature

Indication of vaginal delivery o Delivery can be accomplished with minimal blood loss Fetus is dead Major fetal malformation

Indication of vaginal delivery •Delivery can be accomplished with minimal blood loss •Fetus is dead •Major fetal malformation

Complication pLacenta previa accreta postpartum hemophage iNcreasing maternal mortality and perinatal mortality

Complication •Placenta previa accreta •Postpartum hemopphage •Increasing maternal mortality and perinatal mortality