Placenta Praevia

Question 1

Define Placenta Praevia.

Answer 1

Placenta lies over the internal os.

• Diagnosed at ≥32 weeks

Question 2

Define Low-lying Placenta.

Answer 2

Placental edge is <2cm from internal os on TVUSS.

Question 3

What are the classifications of placenta praevia?

Answer 3

Question 4

What are the risk factors for placenta praevia?

Answer 4

• Multiple pregnancy
• Increased maternal age
• Previous uterine surgery (i.e. CS)
• Previous praevia history
• Smoking
• IVF (6x increased risk)

Question 5

What are the signs and symptoms of placenta praevia?

Answer 5

• Painless PV bleeding - 2^nd or 3^rd trimester
• Potential signs of shock

Question 6

What are the appropriate investigations for suspected placenta praevia?

Answer 6

• 1st line diagnosis: TVUSS
• Bloods – FBC, clotting studies, G&S, U&E, LFT
• Kleihauer test/Rhesus status
  
  • If mother if RhD -ve → administer anti-D
• CTG

Question 7

What must not be done on a women with (suspected) placenta praevia?

Answer 7

BIMANUAL

• Speculum is okay to assess bleeding

Question 8

What is the general management of placenta praevia?

Answer 8

• Advise not to have sex
• Delivery will be by caesarean section

Question 9

What is the management of minimal bleeding in placenta praevia?

Answer 9

• Check the cause is local vaginal bleeding
• Symptomatic management - if cervical carcinoma is excluded
• Admitted for 48 hours for observation

Question 10

What is the management of a low-lying placenta at a 20-week scan?

Answer 10

• Rescan at 32 weeks → if still present rescan at 36 weeks → if still low, recommend CS
• USS at 36 weeks → method of delivery:
  
  • CS (grade III/IV at 37 weeks)
  • Vaginal delivery (grade I)
• 10% go on to have a low-lying placenta later in pregnancy

Question 11

What is the management of a placenta praevia with bleeding?

Answer 11

• ABC and IV access with fluids
• Bloods - FBC, G&S, consider crossmatch, Kleihauer test
  
  • Anti-D if Rh-D -ve and Kleihauer test
  • Steroids (between 24-34(+6) weeks)
• Scans:
  
  • CTG if >27 weeks
  • Umbilical artery dopplers (every 2 weeks)
  • Growth scan
  • Induction of labour if early foetal compromise
  • Admit at least until bleeding has stopped (and keep them in for 48 hours to observe)

Question 12

What are the complications of placenta praevia?

Answer 12

• Maternal mortality is 1 in 300
• Maternal – haemorrhage, DIC, hysterectomy
• Foetal – IUGR, death