Placenta Praevia

Question 1

What is placenta praevia?

Answer 1

When the placenta is attached to the lower uterine segment, lower than the presenting part of the fetus

Question 2

What is the main complication of placenta praevia?

Answer 2

Antepartum haemorrhage

Question 3

What is antepartum haemorrhage?

Answer 3

Vaginal bleeding from week 24 of gestation until delivery

Question 4

What are the four classifications of placenta praevia?

Answer 4

Minor Praevia

Marginal Praevia

Partial Praevia

Complete Praevia

Question 5

What is minor praevia (grade one)?

Answer 5

A placenta in the lower uterus that doesn’t reach the internal cervical os

Question 6

What is marginal praevia (grade two)?

Answer 6

A placenta which reaches, however doesn’t cover, the internal cervical os

Question 7

What is partial praevia (grade three)?

Answer 7

A placenta which partially covers the internal cervical os – specifically covering before dilation however not when dilated

Question 8

What is complete praevia (grade four)?

Answer 8

A placenta which completely covers the internal cervical os

Question 9

What is the difference between low-lying placenta and placenta praevia?

Answer 9

Low-lying placenta is the term used when the placenta is within 20mm of the internal cervical os

Placenta praevia is the term used when the placenta is over the internal cervical os

Question 10

What are the five risk factors of placenta praevia?

Answer 10

Previous C-Section

Maternal Age > 40

Multiple Pregnancy

Multiparity

Previous Placenta Praevia

Question 11

What is the most common risk factor of placenta praevia?

Answer 11

Previous C-Section

Question 12

What are the two clinical features associated with placenta praevia?

Answer 12

Painless Vaginal Bleeding

Shock

Question 13

What is the cause of bleeding in placenta praevia?

Answer 13

This bleeding is due to separation of the placenta, as the lower uterine segment forms and the cervix effaces

Question 14

Which blood vessels rupture in placenta praevia?

Answer 14

Venous sinuses in the lower segment

Question 15

What are the two features of shock?

Answer 15

Tachycardia

Hypotension

Question 16

What are the two investigations used to diagnose placenta praevia?

Answer 16

Abdominal Ultrasound Scan

Transvaginal Ultrasound Scan

Question 17

When are abdominal ultrasound scans used to diagnsoe placenta praevia?

Answer 17

They detect placenta praevia at the routine 20 weeks scan

Question 18

What is the gold standard investigation is used to diagnose placenta praevia?

Answer 18

Transvaginal US scan

Question 19

What are the three features of placenta praevia on US scan?

Answer 19

Reduced Distance Between Placenta & Internal Cervical Os

Abnormal Fetal Lie & Presentation

Normal Fetal Heartbeat

Question 20

Do we conduct vaginal examination for placenta praevia diagnosis? Why?

Answer 20

No

There is an increased risk of severe haemorrhage

Question 21

How do we manage a low-lying placenta which presents on the 20 week abdominal ultrasound scan?

Answer 21

We conduct a transvaginal ultrasound scan at 32 weeks

In cases where the placenta praevia is still present at 32 weeks, we rescan every 2 weeks following this

Once 36 weeks gestation, a final ultrasound scan is used to determine the method of delivery

Question 22

What delivery method is recommended in grade one placenta praevia patients?

Answer 22

Vaginal Delivery

Question 23

What delivery method is recommended in grade three and four placenta praevia patients? When should this be conducted?

Answer 23

Elective C-sections

37 - 38 weeks gestation

Question 24

How do we manage placenta praevia, with active bleeding?

Answer 24

Admit

ABC Approach

Question 25

In which two cirucmstances is emergency c-section recommended to manage placenta praevia patients, with active bleeding?

Answer 25

Unstable > ABC Approach

Labour

Question 26

When do we prescribe anti-d to placenta praevia patients?

Answer 26

Within 72 hours of bleeding - if the woman is rhesus D negative

Question 27

What are the four complications of placenta praevia?

Answer 27

Antepartum Haemorrhage

Postpartum Haemorrhage

Preterm Labour

Stillbirth