Abortion

• expulsion of dead foetus before 24 weeks gestation

• up to 12 weeks

  1. haemorrhage into decidua basalis - local necrosis and inflammation

  2. ovum acts as foreign body and uterus contracts, cervix begins to dilate

  3. expulsion completed, decidua shed as lochial flow over next few days

• between 12 and 24 weeks

  • gestational sac ruptures , expelling foetus

  • placenta may be retained

Causes

• Abnormal development of ovum

• Maternal condition

  • pyrexia illness

  • infection

  • severe rhesus iso-immunisation

  • chronic maternal disease

• Cervical incompetence

  • abortion in mid-trimester

• Fibroids

• Congenital abnormality of uterus

Types

• Threatened abortion

  • any bleeding before 24th week

  • impossible to distinguish from decidual shedding

• Inevitable abortion

  • bleeding may be slight

  • uterine contractions have started to dilate cervix

  • USS may demonstrate foetal death

• complete

  • uterine contraction felt

  • cervix dilates

  • foetus and placenta expelled completely

  • bleeding stops

• incomplete

  • only foetus and some membranes expelled

  • substantial bleeding continues and painful contractions

• missed abortion

  • death of foetus unnoticed, bleeding ignored as threatened abortion

  • uterus shrinks, pregnancy test becomes negative

  • USS to confirm

Management

• USS to check for foetal heartbeat

• bleeding of incomplete abortion may be stopped by 0.5mg ergometrine +/- pethidine, may need blood transfusion

Differential diagnosis

• tubal pregnancy

• hydatidiform mole

• menstrual disorders

Surgical Treatment

• in theatre

• 'digital curretage'

• injection of syntometrine to contract and harden uterus

• removal of placental tissue with ovum forceps, currette

Retention of dead foetus

• Forms

  • Carneous mole

  • Macerated foetus

    • skull bones collapse, spine flexed on X-ray (Spalding's sign)

    • mummification (fetus papyraceous), calcification (lithopaedion) rare

• should be expelled spontaneously

• risk of coagulation defect - check if evacuating after 4 weeks

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