Antepartum Haemorrhage Flashcards
A woman at 35 weeks gestation presents with vaginal bleeding. This began 15 hours ago after she felt some wetness . There has been no pain but the bleeding has been consistent.
On CTG the foetus shows signs of bradycardia
What is the most likely cause?
Vasa previa
this is the classic triad of symptoms - rupture of membranes, painless bleeding and foetal bradycardia (+/- decelerations)
What is the definition of antepartum haemorrhage?
This is when there is vaginal bleeding anytime from 24 weeks gestation up until the second stage of labour.
How many mls is classified as a minor bleed?
<500mls
To classify a major haemorrhage, how much blood would be lost?
500-1000mls
In a massive haemorrhage, how much blood would be lost?
> 1000 mls
+/- clinical signs of shock
A term used to describe a placenta laying either partially or fully over the cervical os:
Placenta previa
If a woman is shown to have a low lying placenta at 18-24 weeks what is done?
Another follow up scan at 32 weeks to see if placenta has moved.
If unsure, a trasnvaginal scan should be done
How does placenta previa typically present?
Painless fresh red bleeding
What cause of antepartum haemorrhage can also be a cause of abnormal foetal lie?
Placenta previa
What are some of the risk factors for placenta previa?
Age
Previous c - section (placenta embeds in scar)
Previous placenta previa
A patient presents 36 weeks gestation with severe abdominal pain. They are not bleeding but are clinically shocked with a BP of 86/60. What is the likely diagnosis?
Concealed placental abruption
No vaginal bleeding is why it’s termed concealed as the blood is being concealed behind the placenta
What is the definitive management for placental abruption?
Emergency c-section
What are some of the consequences of a placental abruption?
Intrauterine death
Post-partum haemorrhage
All other medical consequences of haemorrhage including DIC, shock, hypovolaemia, multiorgan failure
What are some of the main risk factors for placental abruption?
Pre eclampsia Unknown Hypertension Cocaine / drug abuse Smoking Renal disease / diabetes / medical thrombophilia Abnormal placenta / previous abruption Polyhydramnios / multiple pregnancy
What is the pathology of vasa previa?
This is when foetal blood vessels in the membrane are lying to close to the os.
Vasa previa does not carry any significant maternal risk. True or false?
True. Unless there are further complications there is mainly only risk to the foetus.
What is the theoretical mechanism behind placental aburption?
Vasospasm followed by rupture of the arteriole in the decidua, blood then escapes into the amniotic sac or under the placenta and into the myometrium. This then leads to clonic contraction of the uterus, clamping on the placental blood supply causing hypoxia
What is the term given to the bluish uterus seen in a placental abruption?
Couvelaire Uterus
Caused by blood between muscle fibres so the uterus appears blue and the uterus doesn’t contract well increasing the risk of postpartum haemorrhage.
List some of the clinical signs of placental abruption:
Unwell / distressed patient (Not necessarily blood to show) Hypovolaemia Uterus large for dates Hard woody uterus Preterm labour Foetal parts hard to find Bradycardia or absence of foetal HR
What will be seen on a CTG in placental abruption?
Irritable uterus with a "zig zag" pattern and minimal contractions Foetal tachycardia (or in later stages bradycardia or intrauterine death) Loss of variability and late decelerations
What is the normal range for variability on a CTG?
5-25
What are the principles of management in placental abruption?
Manage mum first - maternal resus
Emergency delivery of baby (C-section)
Administer Anti-D if needed
Debrief later with families regarding future risks in pregnancy
Is vasa previa routinely screened for?
No it is extremely rare
What is the foetal mortality rate of vasa previa?
60%
What are the main principles of management in vasa previa?
Detection early Steroids from 32 weeks ? inpatient management if high risk Elective c-section 34-36 weeks Placenta to histology to confirm diagnosis
In a patient with acute maternal collapse in the absence of bleeding and a soft uterus - foetal parts being palpable, what diagnosis should be considered?
Uterine rupture
This is mainly a clinical diagnosis - any suspicion and emergency surgery is probably the right answer as their is a high mortality rate for both mother and baby
What are some potential risk factors for uterine rupture?
Previous uterine surgery which breached the uterine cavity e.g. c-section, myotomy, fibroid removals etc
Multiparity
Obstructed labour
Over stimulation through excessing infusions of syntocinon or prostaglandins
How is a uterine rupture managed?
Emergency c section and foetal resus if required
Hysterectomy is sometimes needed depending on the uterine damage
What are some of the risk factors for vasa previa?
IVF / assisted conception Multiparity Abnormal placenta (lobed) Multiple pregnancy History of low lying placenta in 2nd trimester in previous pregnancies
Describe a Type 1 vasa previa
There is a velamentous insertion to the umbilical cord with vessels running over the surface of the os.
Describe a Type 2 vasa previa
This is where there is a succenturiate or accessory lobe and there are unprotected vessels running between them and the main body of the placenta
What investigation would be appropriate in a query vasa previa?
Doppler USS initially transabdominal and then transvaginal if appropriate
Why does vasa previa have a significantly high foetal mortality rate?
Baby is at risk of bleeding to death
Painless usually
Why does placental abruption sometimes lead to massive PPH?
The blood caught in the myometrium of the uterus prevents it from properly contracting one the baby has been delivered.
Uterine atony is the commonest cause of PPH
