Placenta accreta describes the attachment of the placenta to the myometrium, due to a defective decidua basalis. As the placenta does not properly separate during labour there is a risk of post-partum haemorrhage.

Risk factors

• previous caesarean section
• placenta praevia

Strictly speaking, there are 3 different types of placenta accreta, depending on the degree of invasion although this is quite small print:

• accreta: chorionic villi attach to the myometrium, rather than being restricted within the decidua basalis
• increta: chorionic villi invade into the myometrium
• percreta: chorionic villi invade through the perimetrium

Management

• 60% of women go on to have a hysterectomy