Placenta praevia (Complete) Flashcards
(19 cards)
Define placenta praevia
Placenta overlying the cervical os
What is a low-lying placenta?
Placenta that is located within 2cm of the internal os but does not cover it
The placenta may move upward as the pregnancy progresses.
What risk factors are associated with placenta praevia?
IVF
Multiple pregnancies
Previous history of praevia
Previous uterine surgery (including C-section)
Smoking
Increased maternal age
What are the main clinical features of placenta praevia?
Demographic: Pregnant woman over 24 weeks gestation
Bright red and painless vaginal bleeding
Haemodynamic instability
- Hypotension
- Tacchycardia
What differentials should be considered alongside placenta praevia?
Placental abruption
Vasa praevia
What investigations should be considered alongside placenta praevia?
Bedside:
CTG: Check for foetal distress
Speculum examination: exclude vaginal/cervical haemorrhage but needs to be done very carefully and requires double setup in case C-section required.
Bloods:
FBC
Group and save and cross match: If transfusion required
Rhesus test
Kleihauer test: If resus negative
Clotting factors
Imaging:
Transvaginal USS: Gold-standard
What examination should be avoided until placenta praevia is ruled out?
Bimanual examination
What is the gold standard diagnostic test for placenta praevia?
TV USS
What are the grades of placenta praevia?
Grade I: Placenta reaches lower segment but not the internal os
Grade II: Placenta reaches internal os but doesn’t cover it
Grade III : Placenta covers the internal os before dilation but not when dilated
Grade IV (‘major’): Placenta completely covers the internal os
How is placenta praevia managed?
Conservative:
Repeat US at 32 weeks
- Grade I & II: Repeat again at 36 weeks if still present followed by C-section at 37 weeks
- Grade III & IV: Advise admission at 34 weeks for monitoring and C-section at 37 weeks
Avoidance of sex and inform need for C-section
Medicine:
Standard resuscitation guidelines for haemorrhage
- e.g. blood transfusions, tranexamic acid
Corticosteroids
- Consider between 24-34 weeks gestation if preterm labour suspected
Anti-D immunoglobulin: If rhesus negative
Surgical:
Emergency C-section
- If foetal comprimise or unable to stabilise patients with moderate/severe bleeding
What advice should be given for woman with placenta praevia?
Advise avoidance of sex
Inform them of need for C-section
Repeat US is typically done at what gestational week?
Week 32
What is management plan if grade I & II placenta praevia found at 32 weeks US?
Repeat US at 36 weeks followed by C-section at 37 weeks
What is management plan if grade III & IV placenta praevia found at 32 weeks US?
Admit for observation at 34 weeks followed by C-section at 37 weeks
How are patients with mild bleeding acutely managed?
Admit for 48 hours for observation and symptom management
How are patients with moderate/severe bleeding acutely managed?
A-E approach following resuscitation guidelines
Anti-D immunoglobulins if rhesus negative
Emergency C-section of foetal or maternal comprimise despite resuscitation attempts
Corticosteroids (24-34 weeks) if preterm labour suspected
What complications can arise due to placenta praevia?
Maternal complications:
- Haemorrhage
- DIC
Foetal complications:
- Death
- IUGR
How does placental abruption differ to placenta praevia?
Painful bleeding
Uterine tenderness and contractions
How does vasa praevia differ to placenta praevia?
Both present with painless bleeding however vasa praevia additionally presents with foetal bradycardia and rupture of membranes
