Avoid vaginal examination as can worsen bleeding
About
- A low lying placenta that can cause bleeding and necessitate a caesarean section
Aetiology
- Placenta praevia is seen in 1 in 200 pregnancies
- There can be severe and rapid blood loss as uterine supply is very high 600-800 mL/min at term
- USS can show a low lying placenta early on but this moves up as the uterus develops
Risks/Associations
- Large placenta e.g. twins
- Uterine fibroids or other abnormalities
- Previous caesarean section
Clinical
- Painless vaginal bleeding - antepartum haemorrhage
- Presents at 29-30 weeks or otherwise later
- Avoid speculum examination which could worsen bleeding
- Normal lie and presentation
- fetal heart normal
- Non tender uterus
Grades
- Complete : Internal os covered entirely
- Partial : Internal os partially covered
- Marginal : Placental edge at cervix
- Low lying: lies in the lower segment
Differential
- Placental abruption which causes vaginal bleeding and Pain
Investigations
- Transabdominal or transvaginal USS will show the low lying placenta
- Check FBC
- Group and cross match
- Check clotting
- baseline U&E
- Cardiotocography should be performed to assess the fetus
Management
- Good IV access and transfuse to Hb > 10g/dl
- Observation in hospital for those from 35 weeks is suggested by some but controversial if there is no bleeding
- Steroids for fetal prematurity
- Caesarean section by consultant