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
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,
Etiology
Mechanism,abnormal vascularization
Predisposing factors,
?Twin pregnancy
?Increasing maternal age
?Increasing parity
?Previous cesarean section
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,
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
Indication of vaginal delivery
?Delivery can be accomplished with
minimal blood loss
?Fetus is dead
?Major fetal malformation
Complication
?Placenta previa accreta
?Postpartum hemopphage
?Increasing maternal mortality and perinatal
mortality
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
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,
Etiology
Mechanism,abnormal vascularization
Predisposing factors,
?Twin pregnancy
?Increasing maternal age
?Increasing parity
?Previous cesarean section
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,
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
Indication of vaginal delivery
?Delivery can be accomplished with
minimal blood loss
?Fetus is dead
?Major fetal malformation
Complication
?Placenta previa accreta
?Postpartum hemopphage
?Increasing maternal mortality and perinatal
mortality
