Placental abruption is more common than the other emergencies, with an incidence between 0.5 - 2% of all pregnancies. Abruptio occurs because of premature separation of a normally sited placenta, with bleeding that may be concealed (33%) or revealed.
An abruption threatens the life of the foetus and the mother. In major degrees of placental abruption the woman is shocked well beyond the apparent amount of blood loss and needs urgent transport into hospital.
These patients present with abdominal pain and shock that is out of keeping with the amount vaginal blood loss. The abdomen is usually tender and the uterus is contracted or hard (woody). It is often difficult to palpate foetal parts and the foetal heart beat is often absent.
The diagnosis is usually a clinical one and can be aided by cardiotocography showing excessively frequent uterine contractions and changes in foetal heart rate secondary to foetal hypoxia. Ultrasound can assist with the diagnosis, but it is not always reliable.
Early management should as always follow Airway, Breathing (oxygen) and Circulation. Treatment must be aimed at the shock and preventing disseminated intravascular coagulopathy. A wide bore intravenous line should be set up and blood sent for cross matching of at least six units of blood. Blood should also be taken to check haemoglobin, platelets and clotting. The laboratory should be informed of the urgency and a haematologist involved if necessary. Until this blood arrives, other plasma expanding fluids, such as Gelofusine, should be used. In severe cases, resuscitation can begin with O-negative blood.
If gestation is sufficiently advanced and the foetus viable, caesarean section is the best management. However, if the foetus is dead, conservative management can be pursued provided that the woman does not continue deteriorating for example, by developing a coagulopathy. Most women with a severe abruption that kills the foetus will go into spontaneous labour soon and have an easy delivery, but caesarean section is occasionally necessary for maternal indications alone.
[i] Management of obstetric hemorrhage; Semin Perinato;l 2003 Feb;27(1):86-104.
[ii] ABC of labour care: Obstetric emergencies;BMJ 1999;318:1342-1345 ( 15 May )
[iii] Perinatal Review Obstetric Emergencies