FRCA Notes

Placenta praevia

Resources

  • Placenta praevia describes implantation of the placenta in the lower uterine segment, over or very near to the internal os of the cervix
  • It is typically diagnosed ante-natally on ultrasound, and is of relevance as it will necessitate LSCS unless the placenta is >2cm from the cervical os
  • Incidence 0.5%
Patient factors Uterine factors
Increased age (>40yrs) Uterine scar e.g. previous LSCS
Smoking Previous ToP
Assisted conception Previous praevia
Multiparous Endometrial scarring e.g. fibroids, endometritis, prev. MROP
Larger placenta e.g. twin pregnancy


Grade Description
1 Does not abut the internal os (low-lying)
2 Reaches margin of internal os (marginal)
3 Partially covers internal os (partial)
4 Completely covers internal os (complete)


  • Patients may be asymptomatic, although it can present with painless ante-partum haemorrhage from 27 - 32 weeks
  • Although initial bleeding may be light and without maternal compromise, it can herald precipitous haemorrhage

  • Consultant obstetrician and consultant anaesthetist-led care as higher risk of morbidity/mortality

Blood management

  • Additional wide-bore IV access
  • Consent for transfusion and cell salvage
  • Cross-matched blood
  • Rapid infuser and cell saver ready
  • TXA

Anaesthetic considerations

  • Low threshold for arterial line
  • Regional anaesthesia is associated with reduced blood loss but patients may require GA and should be consented as such
  • Choice of anaesthetic depends on the clinical context
    • For elective LSCS, RA may be appropriate
    • For emergency LSCS, GA may well be required as well as management of major obstetric haemorrhage