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Introduction

Antepartum hemorrhage (APH) describes any PV bleeding after 24 weeks gestation . There can be many causes, but the most common are placenta praevia and placental abruption.

  • About 50% of cases have no cause identified
All bleeds during pregnancy are associated with increased risk of fetal death. Antepartum Hemorrhage also presents a mortality risk to the mother.

Epidemiology and Aetiology

Obstetric haemorrhage which is a term that encompasses antepartum haemorrhage and postpartum haemorrhage is an important cause of maternal mortality worldwide, and historically. However, with the advent of modern medicine, the risk is greatly reduced. In the UK, it is believed the risk of death from obstetric haemorrhage is about 5 per 1 million pregnancies.
  • Affects 3-5% of all pregnancies
  • Associated with premature delivery – 20% of cases are associated with antepartum haemorrhage

Causes

  • 50% of cases of APH have no identified cause
  • Placenta praevia
  • Placental abruption
  • Localised causes (below)
  • Partner violence
  • Rare causes
    • Uterine rupture
    • Vasa praevia – bleeding from fetal blood vessels
    • Inherited bleeding disorder

Localised causes

  • Cervical erosions / ectropion – ectropion is a normal variation of the cervical os, whereby columnar epithelium from the lining of the uterus extend down to the vaginal surface of the os. It is often seen in young women and in pregnancy. It may appear slightly inflamed, and can cause discharge and bleeding (often on contact – i.e. post-coital, but sometimes spontaneous)
  • Cervical Carcinoma – just because the woman is pregnant does not mean she cant have cervical cancer too! Can be difficult to distinguish ectropion and cervical cancer from history alone (usually contact / post-coital bleeding), but cancer is more likely to be hard and irregular, whereas ectropian will look like a surface lesion.
  • Cervical polyps
  • Cervicitis
  • Vulval varicosities

Placenta Praevia

This is a condition whereby the placenta is implanted unusually low within the cervix (within the bottom 1/3), resulting in increasing risk of APH and problems during labour.
It occurs in about 1/200 pregnancies, and doesn’t usually present until >20 weeks. In instances where praevia is noted <20 weeks, it often resolves as the placenta grows.
Placenta Praevia - A common cause of Antepartum Hemorrhage

Placenta Praevia – A common cause of Antepartum Hemorrhage

Risk factors

  • Multiparity
  • Previous c-section
  • Uterine abnormalities (e.g. fibroids or previous curettage)
  • Smoking
  • Older maternal age
  • Multiple pregnancy
There are four classifications:
  • Placenta Praevia type I – the placenta is in the lower 1/3 of the uterus, and close to the cervical os
  • Placenta praevia type II – the placenta reaches the edge of the cervical os
  • Placenta praevia type III – the placenta partially covers the os
  • Placenta praevia type IV – the placenta totally covers the os
Many cases are identified on normal routine pregnancy ultrasound scans. Most cases are minor and will not result in APH.
It is recommended that any women with identified placenta praevia <2cm from the cervical os (or covering the os) undergo planned Caesarian section – usually at 38 weeks.
It is also recommended that they refrain from sexual intercourse to reduce the risk of bleeding.
Placenta accreta
Placenta accreta is an associated disorder, whereby the placenta is unusual adherent to the uterine lining. It is most commonly seen in women with previous placenta praevia whom have undergone Caesarian section. At risk patients be identified by Doppler USS, although it can only be formally diagnosed at surgery.
  • Placenta accreta results in a retained placenta and is a cause of massive postpartum haemorrhage
  • Increased risk of pre-term delivery – 40% of women deliver before 40 weeks
  • Risk increased by previous Caesarian section, especially if placenta praevia and previous c-section

Acute presentation

  • Painless PV bleeding, with bright red blood. Usually starts off light and becomes heavier. Sometimes there may be accompanying contractions.
    • If the bleeding is especially heavy, the mother may be shocked. The degree of shock will typically correlate to the degree of blood loss
  • Uterus is often soft and non-tender
  • The foetus is often in an abnormal lie
    • Foetal heart sounds are however usually normal

Placental Abruption

In this condition, part of the placenta separates from the lining of the uterus, with the accumulation of blood between the placenta and the fetus. It causes about 30% of cases of APH.
Bleeding can be:
  • Concealed – 20% of cases. Blood loss is often underestimated and there is no or very minimal PV bleeding. This form is more dangerous
  • Revealed – 80% of cases. Blood drains through the cervix, often with partial detachment of the placenta from the uterus
Risk factors include:
  • Previous abruption
  • Trauma
    • Road traffic accident
    • Domestic violence
  • Pre-eclampsia
  • Hypertension
  • Multiple pregnancy
  • Previous Caesarian section
  • Previous pelvis surgery
  • Thrombophilia
  • Smoking
It occurs after 20 weeks gestation, and in about 1% of pregnancies. Foetal mortality ranges from 20-40%.
Placental Abruption - another cause of antepartum hemorrhage

Placental Abruption – another cause of antepartum hemorrhage. Image from: Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436.

Acute presentation

  • Usually a single instance of large blood loss
    • The amount of blood loss may not be correlated to the degree of maternal shock
  • Constant pain and contractions
  • A hard, painful, tender, sometimes enlarged uterus
    • Often described as a “woody feel”
  • Foetal lie is usually normal
  • Foetal heart may be distressed / abnormal
  • Ultrasound is NOT useful at identifying placental abruption
  • Diagnosis is clinical – there is no diagnostic test

Complications

  • Placental abruption also increases the risk of PPH (Post-Partum Haemorrhage)

Presentation

  • PV bleeding
    • With pain – suggests abruption
    • Without pain – suggests praevia
  • Uterine contractions
  • Signs of hypovolaemic shock (if bleeding is severe – often a very late sign)
    • Tachycardia
    • Hypotension
    • Increased respiratory rate
    • Confusion or drowsiness
    • Loss of consciousness

Investigations

  • FBC
    • Low Hb is often a late sign
  • “Group and save”
    • Blood group and antibodies for possible transfusion
    • Crossmatch immediately if massive transfusion
  • Clotting studies
    • Assessing for underlying clotting abnormalities
  • U&E
  • LFTs
  • Urgent ultrasound
    • Can exclude or confirm placenta praevia
    • Cannot exclude placental abruption – this is a clinical diagnosiS

Management Principles

  • Any bleeding after 24 weeks should be referred to the emergency department
    • ALWAYS admit these patients!
  • Give 15L O2
  • Get IV access, and set up drip
  • Order blood (if shocked) or crossmatch if not
  • Ensure systolic BP >100
  • Get clotting screen (for thrombophilia)
  • Catheterise – keep urine output >30ml/hour
  • Get expert help!
  • Ultrasound (transvaginal or abdominal) and speculum exam to get diagnosis
  • WARNING – digital vaginal exam can increase the bleeding in placenta praevia, – and be fatal, and thus is contra-indicated until this has been excliuded.
  • Large amounts of bleeding can be masked – as much of the blood can be retained, and there may only be a small amount of PV bleeding
  • Assess the severity of blood loss
    • Minor – <50mls and bleeding has ceased
    • Major – 50 – 1000mls with no signs of shock
    • Massive – >1000mls AND / OR signs of shock
  • Assess the need for anti-D
  • Maternal corticosteroids
    • Should be offered to any mother who is at risk of pre-term delivery I.e. – between 24+0 and 35+6 gestation
    • These help to increase rate of fetal lung maturation in readiness for delivery

Placenta praevia

  • If very severe at presentation, immediate delivery may be necessary
  • If not immediately life threatening to mother of foetus, patients will usually require inpatient care until delivery
  • Delivery is usually by elective caesarean section at 37-38 weeks
  • Amniocentesis may be performed at 36 weeks to asses foetal lung maturity in readiness for delivery
  • Steroids may be considered if presentation occurs <34 weeks to accelerate fetal lung maturation in case pre-term delivery is required,
  • Delivery is indicated if: massive loss of blood / maternal shock or life in danger, fetal distress noted on CTG
  • Vaginal delivery is possible, but is often difficult, and results in the loss of the fetus.

Placental abruption

  • May require emergency c-section
  • If it settles, and patient is stable, then in some cases patients can be discharged and followed up as high-risk pregnancy

Prognosis

  • Fetal mortality is about 120 per 1000 births in placental abruption

References

  • Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
  • Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
  • Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy

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