Placenta praevia Flashcards
Placenta praevia
Placenta lying wholly or partly in the lower uterine segment
Associated factors
Multiparity
Multiple pregnancy
Embryos are more likely to implant on a lower segment scar from previous c-section
Clinical features
Shock in proportion to visible loss
No pain
Uterus not tender
Lie and presentation may be abnormal
Fetal heart usually normal
Coagulation problems rare
Small bleeds before large
Diagnosis
Digital vaginal examination should NOT be performed before an US as may provoke severe haemorrhage
Often picked up on routine 20 week abdominal US
Transvaginal US as it improves accuracy of placental localisation and is considered safe
Classical grading
1- placenta reaches lower segment but not the internal os
2- placenta covers the internal os before dilation but not when dilated
3- placenta covers the internal os before dilation but not when dilated
4- placenta completely covers the internal os
Management if low-lying at 20 week scan
Rescan at 32 weeks
No need to limit activity or intercourse unless they bleed
If still present at 32 weeks and grade 1/2 then scan every 2 weeks
Final US at 36-37 weeks to determine method of delivery
Elective c-section for grades 3/4 between 37-38 weeks
If grade 1 then trial of vaginal delivery
If known placenta praevia goes into labour prior to elective c-section
Perform emergency c-section due to the risk of post-partum haemorrhage
Placenta praevia with bleeding
Admit
A-E approach to stabilise the woman
If not able to stabilise then emergency c-section
If in labour or term reached then emergency c-section
Prognosis
Death is now extremely rare
Major cause of death in women with placenta praevia is now PPH
