Placental Abruption

Placental abruption (20% of all cases of antepartum haemorrhage):

A normally situated placenta separates from the uterus prematurely and blood collects between the placenta and the uterus.

It occurs in 1 in 200 of all pregnancies.

The cause of placental abruption is unknown but it is more common with:=

 

Increasing maternal age and parity.

High blood pressure

Trauma (usually a car accident or maternal battering)

Smoking

Prolonged rupture of membranes.

Abruption in a previous pregnancy

 

• Presentation

  May present with vaginal bleeding, abdominal pain, uterine contraction, shock or foetal distress.

  May not be demonstrable on ultrasound as the blood clot is not easily distinguishable from the placenta.

  Moderate placental detachment and haemorrhage: at least one quarter of placenta has become detached and less than 1000ml of blood lost. Abdominal pain and tender uterus, mother may be in shock, fetus is hypoxic and may show abnormal heart rate patterns.

  Severe placental detachment and haemorrhage: at least 1500ml of blood lost, shock usual, uterus firm-to-hard and very tender. Fetus almost always dead. Hypotension in 1/3 of cases, but may be normal in spite of shock. Coagulopathy common.

Management

May need resuscitation measures if shocked.

Admit to hospital, even if bleeding is only a very small amount. There may be a large amount of concealed bleeding with only a small amount of revealed vaginal bleeding.

No vaginal examination should be attempted at least until a placenta praevia is excluded by ultrasound as this could initiate torrential bleeding from a placenta praevia.

Resuscitation can be inadequate because of under-estimation of blood loss and misleading maternal response. A young woman may maintain a normal blood pressure until sudden and catastrophic decompensation occurs

Take blood for full blood count and clotting studies. Cross match as heavy loss may require transfusion.

Gentle palpation of the abdomen to determine gestational age of fetus, presentation and position.

Fetal monitoring.

Arrange urgent ultrasound.

With every episode of bleeding, a Rhesus negative woman should have a Kleihauer test and be given prophylactic anti-D immunoglobulin.

Further management will depend on fetal distress, the cause of the APH, extent of bleeding and gestation:

For pre-term delivery and immediate delivery is not necessary, maternal steroids may be indicated in order to promote fetal lung development and reduce the risk of respiratory distress syndrome

Severe bleeding or fetal distress may require urgent delivery of baby irrespective of gestational age.

Less severe bleeding, fetus less than 36 weeks and not distressed: expectant treatment with mother in hospital. If no further severe bleeding, continue pregnancy until 38 weeks when delivery mode can be chosen depending on degree of placenta praevia.

In slight haemorrhage with blood loss less than 500 ml and no disturbance of maternal or fetal condition. Ultrasound shows placenta not lying in lower uterine segment, no retroplacental clots. Patient may be discharged or have baby induced if after 37 weeks and other conditions suitable.

Moderate or severe placetal abruption:

Restore blood loss, prevent coagulopathy, monitor urinary output. In moderate cases, give 1500 ml of blood, and in severe cases, give 2500 ml (first 500 ml transfused rapidly). Ideally measure central venous pressure (CVP) and adjust transfusion accordingly.

Measure venous blood for coagulation 2 hourly, treat accordingly.

Measure urine output 2 hourly. Oliguria may occur, but if sufficient blood has been given, then diuresis will follow birth.

If fetus is alive, perform either caesarean section or artificial rupture of the amniotic membranes (restore blood volume first). Monitor fetus and switch to caesarean if fetal distress develops.

Vaginal delivery is the treatment of choice in the presence of a dead fetus³.

Complications

Premature labour.

Disseminated intravascular coagulopathy.

Renal tubular necrosis.

Postpartum haemorrhage.

Prognosis Fetus may die from hypoxia during heavy bleeding. Perinatal mortality less than 50 per 1000, maternal mortality is low if managed by experienced obstetrician and no vaginal examination performed before admission to hospital.

References Used

1. Lijoi AF, Brady J; Vasa Previa Diagnosis and Management. J Am Board Fam Pract.;2003 Nov-Dec;16(6):543-8.
2. Crochetiere C; Obstetric emergencies. Anesthesiol Clin North America 2003 Mar;21(1):111-25.
3. Health Evidence Bulletins: Wales; Haemorrhage in late pregnancy (and labour). June 1997.
4. Royal College of Obstetricians and gynaecologists; Antenatal corticosteroids to prevent respiratory distress syndrome. February 2004. [As PDF]
5. Neilson JP; Cochrane Database of Systematic Reviews; Interventions for suspected placenta praevia. 2003.