Placenta previa Flashcards
What is placenta previa?
Placenta attached lower portion uterus
Low-lying placenta cs placenta previa
Low-lying - when placenta within 20mm of internal cervical os
Previa - placenta over internal cervical os
What are three causes of antepartum haemorrhage?
Placenta previa
Placental abruption
Vasa previa
Cuases of spotting or minor bleeding
Cervical ectrpion
Infection
Vaginal abrasions from intercourse or procedures
Symptoms of placenta previa
Painless antepartum bleeding
Bleeding usually massive - pool of blood
Signs of placenta previa
Size of uterus expected for GA
Pallor
Head floating
Uterus soft non tender
Foetal heart sounds present
Slowing of foetal heart when pressed down into prelvis with quick recovery when released (Stallworthys sign)
What is stallworthys sign
Slowing of foetal heart when pressed down into prelvis with quick recovery when released
What should not be performed in placenta previa?
Vaginal examination
Risk factors with placenta previa
Antepartum haemorrhage
Emergnecy C section
Emergency hysterectomy
Maternal anaemia and transfusions
Preterm birth and low birth weight
Stillbirth
Grades of placenta previa
Minor previa or grade I
Marginal praevia or grade II
Partial previa or frade III
Complete previa or grade IV
What is the difference between minor and marginal praevia?
Minor - Placenta is in lower uterus but not reaching internal cervical os
Marginal - placenta reaching but not covering internal cervical os
Partial vs complete praevia
Partial/III - covering internal cervical os
Complete/IV - placenta completely covering internal cervical os
What grading should be used for placenta previa?
RCOG - grading is outdated
Either low lying or placenta previa
What grading should be used for placenta previa?
RCOG - grading is outdated
Either low lying or placenta previa
Risk factors for placenta previa
Prev C sections
Prev placenta previa
Older maternal age
Maternal smoking
Structural urine abnormalities
Assisted reproduction
