QuestionSBA
QuestionChoice
Placenta increta occurs where the placental villi invade into, but not through, the myometrium.
49988
b
Placenta increta
QuestionChoice
Placenta praevia occurs where the placenta overlies the cervical os. This can result in antepartum haemorrhage, and is usually diagnosed antenatally.
49990
d
Placenta praevia
QuestionChoice
Vasa praevia occurs where the foetal vessels run near to or across the internal cervical os, unsupported by the umbilical cord or placental tissue. This can cause antepartum haemorrhage due to rupture of the foetal vessels during rupture of membranes.
49991
e
Vasa praevia
QuestionChoice
Placenta percreta occurs where the placental villi invade through the full thickness of the myometrium to the serosa.
49989
c
Placenta percreta
QuestionChoice
Placenta accreta occurs where the placental villi adhere directly to the superficial myometrium. In placenta accreta, the placental villi do not penetrate into the myometrium itself. Placenta accreta is the most common placental implantation abnormality, and is typically diagnosed antenatally.
49987
a
Placenta accreta
Concept
Chapter
# Summary

Placental accreta refers to a spectrum of abnormalities involving the implantation of the placenta into the uterine wall. It is associated with various risk factors such as previous pregnancy termination, dilation and curettage, caesarean section, advanced maternal age, placenta praevia, and uterine structural defects. Diagnosis may be difficult to establish antenatally, with Doppler ultrasound and MRI scanning providing valuable information. Placental accreta can lead to complications like severe postpartum bleeding, preterm delivery, and uterine rupture. Management strategies often involve an elective caesarean section and hysterectomy, but in cases where fertility preservation is necessary, a less destructive placental resection may be performed.


# Definition

Placental accreta is a spectrum of abnormalities of placental implantation into the uterine wall.

# Risk factors

Risk factors for placental accreta spectrum include:

- Previous termination of pregnancy
- Dilatation and curettage
- Previous caesarean section
- Advanced maternal age
- Placenta praevia
- Uterine structural defects

# Classification

**Placenta accreta** occurs where adherence of the placenta directly to superficial myometrium but does not penetrate the thickness of the muscle.

**Placenta increta** occurs where the villi invade _into_ but not _through_ the myometrium

**Placenta percreta** occurs when the villi invade through the full thickness of the myometrium to the serosa. There is increased risk of uterine rupture and in severe cases the placenta may attach to other abdominal organs such as the bladder or rectum.

# Diagnosis

Doppler ultrasound and MRI scanning are useful investigations, but antenatal diagnosis can be difficult to make.

# Complications

Abnormal implantation of the placenta can lead to increased risk of severe postpartum bleeding, preterm delivery and uterine rupture.

# Management

If abnormal placental implantation is suspected, the safest management plan is often an elective caesarean section and hysterectomy.

If it is important to preserve the patient's fertility, a less destructive placental resection may be attempted.
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Placenta Accreta Spectrum
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Obstetrics
Video
Concept
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Placenta Accreta Spectrum
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Placenta praevia 1
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A 39-year-old woman is scheduled for an elective caesarean section due to a previous caesarean section at 38+4 weeks gestation.

A lower uterine segment caesarean section is performed and a live male infant is delivered. Following delivery of the infant, there is brisk bleeding from the placental site, and the placenta is found to be adherent to the uterine wall.

Bleeding is unable to be controlled and the lower uterine segment is closed and a total hysterectomy is performed.

Pathology reports an abnormally adherent placental with the placental villi adhering directly onto the superficial myometrium.

What is the most likely reason for this patient's postpartum haemorrhage?
a