Placenta praevia and placenta accreta: Diagnosis and management - GTG 27a - 2018 Flashcards
What are the risk factors for placenta praevia or LLP?
Caesarean section
Assisted reproductive techniques
Smoking
pregnancy within a year of a caesarean
What is the difference between the terms placenta praevia and LLP?
Placenta praevia should only be used when the placenta lies directly over the internal os
LLP should be used when the placental edge is within 20mm of the internal os and the pregnancy is >16 weeks gestation.
If LLP or praevia is diagnosed at 20 week scan when does the RCOG recommend repeat US?
TV USS at 32 weeks
If it persists and they are asymptomatic an additional TVS at around 36 weeks is recommended to inform discussion about MOD.
Is cervical length scan informative in women with LLP/praevia?
a short cervical length on TVS before 34 weeks increases the risk of preterm emergency delivery and MOH at caesarean.
Should women with LLP/praevia be offered antenatal corticosteroids?
a single course of AN steroids is recommended between 34 and 35+6 for women with LLP or praevia.
It is appropriate before 34 weeks for those with a higher risk of PTB.
Is tocolysis appropriate for women with symptomatic LLP/praevia in suspected preterm labour?
May be considered to facilitate antenatal corticosteroids.
If delivery is indicated for fetal or maternal concerns tocolysis should not be used.
When should planned delivery occur for women with LLP/praevia?
Late preterm (34-35+6) should be considered for those with vaginal bleeding or other risk factors for PTB
For those with uncomplicated praevia delivery should be considered between 36 and 37 weeks.
Where should women with anterior LLP/praevia be cared for?
anterior LLP/praevia have a higher risk of MOH and hysterectomy.
Delivery should be arranged in a unit with on site transfusion services and access to critical care.
who should be present for the planned caesarean of a woman with praevia or LLP?
A senior obstetrician (usually a consultant) and a senior anaesthetist (usually a consultant) should be present in the theatre.
What anaesthesia is most appropriate for women having a caesarean with LLP or praevia?
lower risk of haemorrhage with regional compared to GA.
Women should be informed that it may be necessary to convert to GA.
what surgical approach should be considered for transverse lie or preterm with LLP or praevia
Consider vertical skin and or uterine incision when the fetus is in transverse lie particularly below 28 weeks.
What should be done if the placenta is transected during the uterine incision in women with LLP/praevia?
The umbilical cord should be clamped immediately after fetal delivery to avoid excessive fetal blood loss.
What are the risk factors for placenta accreta spectrum (PAS)
history of accreta
previous caesarean delivery
previous uterine surgery
for the diagnosis of PAS is MRI or US superior?
the diagnostic value is similar when performed by experts.
MRI can complement US, to help assess depth of invasion.
When should women with PAS have planned delivery?
In the absence of risk factors for PTB women with PAS should have planned delivery between 35 and 36 weeks.
This provides the best balance between fetal maturity and unscheduled delivery.
