Antepartum haemorrhage Flashcards
What roles does the placenta play for the foetus?
Sole source of nutrition from 6 weeks
Has functions including:
- Gas transfer
- Metabolism/waste disposal
- Hormone production (HPL & hGh-V)
- Protective ‘filter’
What is antepartum haemorrhage (APH)?
Bleeding from the genital tract after 24 weeks gestation and before the end of the second stage of labour
i.e. >24/40 and before baby delivered
Commonest causes of APH?
Placenta praevia
Placental abruption
Aetiology (causes) of APH?
Placental Problems - Placenta Praevia, Placental Abruption
Uterine problem - rupture
Vasa Praevia
Indeterminate
Local cause - ectropion, cancer, polyp, infection.
What can APH be mistaken for?
Bloody show (cervix preparing for labour, opening of cervix causes rupture of surrounding blood vessels).
Urinary tract related problems
Haemorrhoids
How is APH quantified?
By a measure of how much bleeding experienced by the woman after 24 weeks gestation.
Spotting = Staining, streaking, wiping.
Minor = <50ml settled
Major = 50-1000ml no shock
Massive= >1000ml and/or shock
What is placental abruption?
refers to when the placenta separates from the wall of the uterus during pregnancy.
The site of attachment can bleed extensively after the placenta separates.
Placental abruption is a significant cause of antepartum haemorrhage.
Risk factors for placental abruption?
Previous placental abruption
Pre-eclampsia
Bleeding early in pregnancy
Trauma (consider domestic violence)
Multiple pregnancy
Fetal growth restriction
Multigravida (pregnant for at least 2nd time)
Increased maternal age
Smoking
Cocaine or amphetamine use
Underlying pathology of placental abruption?
Vasospasm followed by arteriole rupture into the decidua; blood escapes into the amniotic sac or further under the placenta and into myometrium
Causes tonic contraction and interrupts placental circulation which causes hypoxia
Results in Couvelaire uterus
What is Couvelaire uterus?
When retroplacental blood after abruption penetrates through the uterine wall into the peritoneal cavity.
Uterus becomes tense and rigid.
Myometrium becomes weakened and may rupture due to increase in pressure from contractions. Both mother and baby lives at risk
Symptoms of placental abruption?
Sudden onset severe abdominal pain that is continuous
Vaginal bleeding (antepartum haemorrhage)
Shock (hypotension and tachycardia)
Abnormalities on the CTG indicating foetal distress
Characteristic “woody” abdomen on palpation, suggesting a large haemorrhage
What is a concealed abruption?
The cervical os remains closed, and any bleeding that occurs remains within the uterine cavity.
The severity of bleeding can be significantly underestimated with concealed haemorrhage.
Difference between concealed and revealed abruption?
Revealed abruption is when the blood loss is observed via the vagina
There are some reliable tests that can be done to diagnose placental abruption. true/false?
False
Clinical diagnosis of placental abruption is based on patients clinical presentation
Placental abruption is an obstetric emergency, what factors influence urgency of treatment?
Depends on:
- The amount of placental separation
- Extent of the bleeding
- Haemodynamic stability of the mother - Condition of the foetus
Initial management of major or massive haemorrhage?
- Urgent involvement of a senior obstetrician, midwife and anaesthetist
- 2 x grey cannula
- Bloods include FBC, UE, LFT and coagulation studies
- Crossmatch 4 units of blood
- Fluid and blood resuscitation as required
- CTG monitoring of the foetus
- Close monitoring of the mother
Is USS useful in APH?
Can be useful in excluding placenta praevia as a cause for antepartum haemorrhage, but is not very good at diagnosing or assessing abruption.
What do rhesus-D negative women require when bleeding occurs and what test is used to quantify dose needed?
Rhesus-D negative women require anti-D prophylaxis when bleeding occurs.
A Kleihauer test is used to quantify how much foetal blood is mixed with the maternal blood, to determine the dose of anti-D that is required.
What is placenta praevia?
The placenta is attached in the lower portion of the uterus, lower than the presenting part of the foetus.
Praevia directly translates from Latin as “going before”.
What is the internal and external os(orifice)?
The internal os(orifice) is the opening between the cervix and the corpus.
The external os(orifice) is the opening between the cervix and vagina.
When is the term “low-lying placenta” used?
used when the placenta is within 20mm of the internal cervical os
When is the term “placenta praevia” used?
used only when the placenta is over the internal cervical os
What % of pregnancies does placenta praevia occur in?
1% of pregnancies. It is regarded as a notable cause of APH.
3 major causes of APH?
Vasa praevia
Placenta praevia
Placental abruption
Serious causes with high morbidity and mortality
Placenta praevia is associated with increased morbidity and mortality for foetus and mother, what are the risks that it can cause?
Antepartum haemorrhage
Emergency caesarean section
Emergency hysterectomy
Maternal anaemia and transfusions
Preterm birth and low birth weight
Stillbirth
How made grades of placenta praevia?
4 grades
Grade 1 praevia or minor praevia description?
the placenta is in the lower uterus but not reaching the internal cervical os
Grade 2 praevia or marginal praevia description?
the placenta is reaching, but not covering, the internal cervical os
Grade 3 praevia or partial praevia description?
the placenta is partially covering the internal cervical os
Grade 4 praevia or complete praevia description?
the placenta is completely covering the internal cervical os
What puts a patient at risk of placenta praevia?
- Previous caesarean sections
- Previous placenta praevia
- Older maternal age
- Maternal smoking
- Structural uterine abnormalities (e.g. fibroids)
- Assisted reproduction (e.g. IVF)
When during gestation is the position of the placenta assessed and placenta praevia diagnosed?
During the 20 week anomaly scan
Many women with placenta praevia are asymptomatic. true/false?
True
May present with painless vaginal bleeding in pregnancy (antepartum haemorrhage).
Bleeding usually occurs later in pregnancy (around or after 36 weeks).
For women with a low-lying placenta or placenta praevia diagnosed early in pregnancy (e.g. at the 20-week anomaly scan), when should a repeat transvaginal ultrasound scan be done?
32 weeks gestation
36 weeks gestation (if present on the 32-week scan, to guide decisions about delivery)
Symptoms of placenta praevia?
Painless bleeding >24 weeks;
Usually unprovoked but coitus can trigger bleeding
Bleeding can be minor eg spotting/ severe
Fetal movements usually present
Signs of placenta praevia?
General:
- Proportional to volume of bleeding ABCDE
Abdomen:
- Uterus soft non tender
- Presenting part high
- Malpresentations –Breech/Transverse/Oblique
Foetal Heart:
- CTG usually normal
Management of placenta praevia?
Resuscitation Mother : ABCDE
Large bore IV Access and G+S
Assess Baby’s condition +/-
Steroids 24-35+6 weeks
MgSO4 if <32 weeks delivery likely for neuroprotection
Anti D if Rhesus Negative
Conservative management if stable and observe in hospital for at least 24-48 hours
What is vasa praevia?
Condition where the foetal vessels are within the foetal membranes (chorioamniotic membranes) and travel across the internal cervical os.
The foetal membranes surround the amniotic cavity and developing foetus. The foetal vessels consist of the two umbilical arteries and single umbilical vein.
Vasa praevia is where the vessels are placed over internal cervical os, before the foetus. True/false?
True
Under normal circumstances, the umbilical cord containing the foetal vessels (umbilical arteries and vein) inserts directly into the placenta.
The foetal vessels are always protected, either by the umbilical cord or by the placenta. true/false?
True
The umbilical cord contains Wharton’s jelly. What is this?
A layer of soft connective tissue that surrounds the blood vessels in the umbilical cord, offering protection.
Risk factors for vasa praevia?
- Low lying placenta
- IVF pregnancy
- Multiple pregnancy
Diagnosis of vasa praevia?
Ultrasound TA (transabdominal) & TV (transvaginal) with doppler
Clinical features of vasa praevia?
foetal distress and sudden dark red bleeding and foetal bradycardia / death
How many types of vasa praevia?
2 types
What is type 1 vasa praevia?
when the vessel is connected to a velamentous umbilical cord
Velamentous cord insertion = a pregnancy complication that happens when the umbilical cord from a foetus doesn’t insert into the placenta correctly
What is type 2 vasa praevia?
when it connects the placenta with a succenturiate or accessory lobe.
The placenta can form into two or more separate lobes, becoming bilobed or multilobed.
A smaller, accessory lobe called a succenturiate lobe can also form. Foetal blood vessels traveling between these lobes may end up positioned above the cervix, causing vasa previa.
Foetal mortality is around 30% in vasa praevia. true/false?
False
~60%
Management of vasa praevia?
- Antenatal diagnosis
- Steroids from 32 weeks
- Consider inpatient management if risks of preterm birth (32-34 weeks)
- Deliver by elective c/section before labour (34-36 weeks)
- APH from vasa praevia = Emergency caesarean delivery
- Placenta for histology
