Placenta accreta

Question 1

What is placenta accreta

Answer 1

Placenta accreta refers to when the placenta implants deeper, through and past the endometrium, making it difficult to separate the placenta after delivery of the baby. It is referred to as placenta accreta spectrum, as there is a spectrum of severity in how deep and broad the abnormal implantation extends.

Question 2

Pathophysiology of placenta accreat

Answer 2

With placenta accreta, the placenta embeds past the endometrium, into the myometrium and beyond. This may happen due to a defect in the endometrium. Imperfections may occur due to previous uterine surgery, such as a caesarean section or curettage procedure. The deep implantation makes it very difficult for the placenta to separate during delivery, leading to extensive bleeding (postpartum haemorrhage).

Question 3

Layers of uterine wall

Answer 3

• Endometrium, the inner layer that contains connective tissue (stroma), epithelial cells and blood vessels
• Myometrium, the middle layer that contains smooth muscle
• Perimetrium, the outer layer, which is a serous membrane similar to the peritoneum (also known as serosa)

Question 4

Where does the placenta normally attach

Answer 4

Endometrium
allows the placenta to separate cleanly during the third stage of labour, after delivery of the baby.

Question 5

What are the types of placenta accreta

Answer 5

Superficial
PLacenta increta
Placenta percreta

Question 6

Risk factors for placenta accreta

Answer 6

Prev PA
Prev endometrial curettage procedures eg miscarriage or abortion
Prev C section
Multigravida
Increased maternal age
Low lying placenta or placenta praevia

Question 7

Presentation of placenta accreta

Answer 7

Placenta accreta does not typically cause any symptoms during pregnancy. It can present with bleeding (antepartum haemorrhage) in the third trimester.
It may be diagnosed on antenatal ultrasound scans, and particular attention is given to women with a previous placenta accreta or caesarean during scanning.
It may be diagnosed at birth, when it becomes difficult to deliver the placenta. It is a cause of significant postpartum haemorrhage.

Question 8

How is placenta accreta diagnosed

Answer 8

Ideally, placenta accreta is diagnosed antenatally by ultrasound. This allows planning for birth.
MRI scans may be used to assess the depth and width of the invasion.

Question 9

What additional management may patients require at birth due to risk of bleeding and difficulty separating the placenta in placenta accreta

Answer 9

Complex uterine surgery
Blood trasnfusions
Intensive care for mother
neonatal intensive care

Question 10

Options duron Caesarean section

Answer 10

• Hysterectomy with the placenta remaining in the uterus (recommended)
• Uterus preserving surgery, with resection of part of the myometrium along with the placenta
• Expectant management, leaving the placenta in place to be reabsorbed over time

Question 11

RCOG guideline if placenta accreta seen when opening abdomen for C section

Answer 11

the abdomen can be closed and delivery delayed whilst specialist services are put in place. If placenta accreta is discovered after delivery of the baby, a hysterectomy is recommended