Antepartum Haemorrhage Flashcards
whats the definition of antepartum haemorrhage
Bleeding from the genital tract after 24 weeks gestation
what is placental praevia
when the placenta implants in the lower part of the uterus,
at which point is a low lying uterus considered placental praevia
persistence beyond 20 weeks gestation as it is normal at this point but it should move by term
what is the classification of placental praevia
minor - lower segment of uterus, away from internal os
major - partially or totally covering the os
what is the aetiology of placental praevia
Majority Unknown
Twins
High parity
Scarred uterus
Increased maternal age
how may placental preavia affect the labour mechanism
it may prevent engagement necessitating a C-section
Mass effect may cause a transverse lie
may be a cause of massive antepartum haemorrhage
what is placental accreta
deep implantation of the placenta into a uterine scar, usually a c-section scar, leading to difficulty separating from the uterus
what is placental percreta
invasion of the placenta through the uterine wall into other structures
what % of patients with a previous C section + placental praevia get placental accreta
10%
whats the presentation of placental praevia
painless antepartum haemorrhage
increases in frequency and intensity over weeks
1/3 do not bleed before delivery
abnormal lie/presentation common
how do you diagnose placental praevia
USS
2nd trimester scan may detect a low lying placenta
There is a repeat scan at 32 weeks to confirm placental praevia
Placenta <2cm from internal os is likely to be praevia at birth, and if the placenta is anterior then a 3D power USS is used to exclude placenta accreta
what investigations do you do if placental praevia is diagnosed
CTG
FBC
Clotting
Cross match
how do you manage placental praevia
Antepartum haemorrhage suspected to be praveia = admit
If <34 weeks steroids are administered
Delivery by elective C-section at 39 weeks
Emergency C section is required is severe bleeding before
Placenta accreta or percreta must be identified earlier on and a clear plan must be made for elective delivery supported by interventional radiology and surgeons
what is placental abruption
partial or total separation of the placenta from the uterus
what are the consequences of placental abruption
further separation
foetal distress
massive antepartum haemorrhage
foetal death (30%)
DIC/Renal failure in mother
what are risk factors for placental abruption
IUGR
Pre-eclampsia
Cocaine use
Maternal smoking
Autoimmune disease
Previous history of placental abruption
Multiple pregnancy
High maternal parity
Trauma
Sudden reduction in uterine volume
what is the common presentation for placental aburption
painful bleeding with dark blood
what are signs of deterioration in a patient with placental abruption
tachycardia
hypotension
how is placental abruption diagnosed
clinical diagnosis
how do you manage placental abruption
Admission required
Delivery – depending on foetal state and gestation
If the foetus is distressed the emergency C section
Otherwise labour is induced by amniotomy (artificial rupture of the membranes)
If no foetal distress and the abruption is minor and the pregnancy is preterm, steroids can be used and the woman monitored, if all symptoms are gone discharge is allowed
Any episode of abruption where delivery is not undertaken causes reclassification of the pregnancy to high risk, due to the much higher risk of post-partum haemorrhage
Maternal ICU may be necessary
what is a ruptured vasa praevia
the foetal blood vessel runs in the membranes in front of the presenting part, this usually results in the umbilical cord being attached to the membranes rather than the placenta
Rupture is more likely with vessels closer to the cervix
what is the typical presentation of a ruptured vasa praevia
Painless, moderate vaginal bleeding occuring around the time of the rupture of the membranes
Accompanied by severe foetal distress
High mortality – foetus does not often survive to c-section
