Placental Abruption Flashcards
What is placental abruption?
When part of the placenta becomes detached from the uterus resulting in bleeding
(Separation occurs between the uterine wall and decidua basalis)
What does the outcome depend on?
Amount of blood loss
Degree of separation
Can it reoccur in subsequent pregnancies?
Yes 4% (19-24% if twice)
What are the distinguishing features?
Shock out of keeping with visible loss Pain constant, in area of abruption Tender, tense uterus - strong muscular layer clamping down to reduce bleeding Normal lie and presentation Fetal heart absent/distressed Coagulation problems Beware pre-eclampsia, DIC, anuria
What risk factors are there?
Abruption in previous pregnancy Pre-eclampsia Smoking Drug misuse - cocaine, methamphetamine (cause vasoconstriction of vessels and abrupt increase in BP) IUGR PROM Multiple pregnancy Increased maternal age >35 Abdominal trauma - car crash, fall, domestic abuse Polyhydramnios Assisted reproduction Intrauterine infection Non vertex presentation Low BMI Thrombophilias
What are the consequences of placental abruption?
Placental insufficiency - may cause fetal anoxia or death
Compression of uterine muscles by blood causes…
Tenderness and may prevent good contraction at all stages of labour
Posterior abruptions may present with…
Backache
Can there be more or less contractions?
More - uterine hypercontractility (>5contractions per 10mins)
Why does DIC occur in 10%?
Due to thromboplastin release
Is it true that abruption is more likely to be related to conditions occurring during pregnancy and placenta praevia is more likely to be related to conditions existing prior to pregnancy?
Yes
When does it typically occur?
After 20 w gestation
Describe the placenta
Formed from mother and fetus Role is to permit gas and nutrient exchange between them Has 2 layers: Decidua basalis - maternal part Chorion - fetal part
What causes it?
Usually due to degeneration of the uterine arteries that supply blood to the placenta - typically from chronic problems such as smoking or HTN
Diseased vessels rupture causing haemorrhage and separation of placenta
What happens if the separation is central or near the margin of the placenta?
Near margin - vaginal bleeding (apparent type)
Central - pocket of blood that stays concealed (concealed type)
What complications can occur?
Maternal : Hypovolaemic shock Sheehan syndrome Renal failure DIC - the decidua basalis layer is rich in thromboplastin, an abruption cause large quantities to be released, which causes widespread clotting Fetal: Intrauterine hypoxia and asphyxia Premature birth
How is it diagnosed?
USS - retroplacental collection of blood, but does not exclude abruption as the sensitivity of detection of a retro-placental clot is poor especially during acute phase
Blood or blood stained amniotic fluid fluid from vagina
How is it treated?
Depends on physiological status of mother and fetus and gestational age
IV fluids and blood products - support circulation and prevent coagulation disorder
If mother stable and pregnancy not far enough - monitor closely
If haemorrhage severe or evidence of fetal compromise - emergency C section
What investigations should be done?
Diagnosis based on symptoms
Investigations to assess extent and physiological consequences of vaginal bleeding
In cases of severe bleeding: FBC, coagulation screen, 4 units of blood cross-matched
Urea, LFTs, electrolytes
CTG after mother stabilised - fetal hypoxia May show repetitive late or variable decelerations, decreased beat to beat variability or bradycardia
Kleihauer-Betke test: detects fetal blood cells in maternal circulation (and help determine the dose of anti D immunoglobulin to give)
What differentials are there?
Abnormal vaginal bleeding during second half of pregnancy usually due to abruption or placenta praevia
Chorioamnionitis
Pre term labour
Uterine fibroid degeneration
Is the onset of symptoms acute and sudden or insidious?
Acute and sudden
Placenta praevia more insidious
Describe the principles of management
Initial resuscitation
Delivery of baby:
- premature delivery before 37 weeks not recommended if no fetal or maternal compromise
- if >37w and bleeding is present as spotting/mucus active intervention unlikely
- antepartum haemorrhage and maternal and/or fetal compromise = immediate delivery
Post natal: active management of third stage of labour (prevent PPH)
Corticosteroids - risk of pre term birth increased, offer single dose between 24-34 weeks
Anti D - to all the non sensitised rhesus neg cases of antepartum haemorrhage (independent of whether routine antenatal prophylactic anti D given)
