placental abruption, placenta praevia + placenta accreata Flashcards
what- placental abruption?
Separation of a normally implanted placenta from the wall of the uterus - partially or totally before the birth of the fetus
risk factors- placental abruption?
-cocaine use
-trauma
-pre eclampsia
-multiple pregnancies
-increasing maternal age
-smoking
-abnormal placenta
presentation- placental abruption?
-sudden onset of continuous abdominal pain + bleeding (bleeding may be concealed)
-Woody hard uterus (suggests a large haemorrhage)
-abnormal CTG indicating fetal abnormalities
management of placental abruption?
Fetus alive and < 36 weeks:
-Fetal distress: immediate caesarean
-No fetal distress: observe closely, steroids, no tocolysis, threshold to deliver depends on gestation
Fetus alive and > 36 weeks:
-Fetal distress: immediate caesarean
-No fetal distress: deliver vaginally
Fetus dead:
-induce vaginal delivery
what is placenta praevia?
when the placenta lies directly over the internal os
what is a low lying placenta?
when the placenta is within 20mm of the internal cervical os
what are the top 3 causes of antepartum haemorrhage?
-placental abruption
-placenta praevia
-vasa praevia
when should placenta praevia be picked up?
it should be picked up at 20 weeks at mid trimester scan
-if low lying placenta or PP detected then it should be rescanned at 32 and 36 weeks
risk factors for placenta praevia?
-Previous C section
-Termination of pregnancy
-Advanced maternal age
-smoking
-assisted conception
Presentation of placenta praevia?
usually picked up at 20 week anomaly scan
-painless bleeding usually in third trimester
investigations- placenta praevia?
usually picked up at routine 20 weeks scan
if low lying placenta or pp found- rescan at 32 and 36 weeks
-transvaginal USS
what exam should NOT be performed until placenta pravia is ruled out?
vaginal exam should NOT be performed until pp has been ruled out- it may cause a severe haemorrhage
management- placenta praevia?
C section if placenta covers os or <2cm from os
Vaginal delivery if placenta >2cm from os and no malpresentation
what- vasa praevia?
Where the fetal vessels are within the fetal membranes (chorioamniotic membranes) and travel across the internal cervical os.
what are the fetal vessels?
2 umbilical arteries and 1 umbilical vein
what protects the fetal vessels ?
-the fetal vessels (2 umbilical arteries and single umbilical vein) are found within the umbilical cord which inserts directly into the placenta
-the umbilical cord contains Wharton’s jelly (soft connective tissue) which protects the vessels
-so they are either protected by the placenta or umbilical cord
what is Velamentous umbilical cord ?
-where the umbilical cord inserts into the chorioamniotic membranes, and the fetal vessels travel unprotected before joining the placenta
what is an accessory lobe of the placenta?
An accessory lobe of the placenta (also known as a succenturiate lobe) is connected by fetal vessels that travel through the chorioamniotic membranes between the placental lobes.
type 1 vasa praevia?
the fetal vessels are exposed as a velamentous umbilical cord
type 2 vasa praevia?
the fetal vessels are exposed as they travel to an accessory placental lobe
risk factors for vasa pravia?
-low lying placenta
-IVF pregnancy
-multiple pregnancy
investigations vasa praevia?
can be picked up on US at 20 weeks
presentation vasa praevia?
Will rupture during labour or at amniotomy - sudden dark red bleeding
management of vasa praevia?
steroids from 32 weeks
emergency C section
