Placental Abnormalities and Complications Flashcards
What is the placenta accreta spectrum?
Range of pathologic adherence of the placenta (accreta, increta, percreta)
What does placenta accreta spectrum include?
Accreta, increta, percreta
What is placenta accreta?
abnormal invasion of the placental villi through the decidua leading to adherence to the myometrium.
What is placenta increta?
abnormal invasion of the placental villi through the decidua and into the myometrium, through to the outer serosa.
What is placenta percreta?
abnormal invasion of the placental villi through the entire uterine wall; it may then invade other organs.
What causes defective endometrial-myometrial interface in placenta percreta?
Scarring
What does defective endometrial-myometrial interface in placenta percreta cause?
Defective endometrial-myometrial interface causes failure of normal decidualisation - this allows the placental villi (trophoblast) to invade further
What leads to massive obstetric haemorrhage in placenta percreta?
Failure to detect and manage placenta accreta
Common risk factor for placenta percreta?
Previous caesarean section
Name 2 other risk factors for placenta percreta?
Other uterine surgery + Increased maternal age
Presentation of placenta percreta
Typically detected in antenatal period: ○ Women with previous CS found to have low-lying placenta are specifically screened with ultrasound scanning
What is the management for placenta percreta?
Caesarean section at 35-37 weeks (This may be uterus-preserving if the accreta is limited and placenta can be safely
separated.
○ Otherwise, RCOG guidelines recommend caesarean section hysterectomy with
placenta left in situ in the uterus.
)
When is the caesarean section performed?
35-37 weeks
What does RCOG recommend if placenta cannot be separated?
Hysterectomy
What is placenta praevia?
Placenta covers internal os of the cervix
What defines a low-lying placenta?
Within 20 mm of internal os (placenta lies within 20 mm of the internal os (but does not cover it)
What is aetiology of placenta praevia?
Blastocyst implants in the lower segmentof the uterus
Causes of bleeding due to placental trauma?
Placental Trauma (or spontaneous) : sexual intercourse, vaginal examination, cervical dilation in labour
What are risk factors for bleeding due to placental trauma?
Previous C-section, IVF, previous placenta praevia
When is antepartum haemorrhage diagnosed?
> 24 weeks
If bleeding < 24 weeks - what do you suspect?
Threatened miscarriage
What is the presentation of antepartum haemorrhage?
Painless bleeding, soft, non-tender uterus
When is bleeding usually diagnosed without symptoms?
20 week anatomy scan
When is a follow up scan indicated for if praevia/ low lying?
At 32 weeks