Placental Abruption

Placental Abruption, or abruption placenta, is described as bleeding due to the separation of a normally situated placenta. It may occur at any stage of pregnancy or labour and affects 1% of pregnancies.

Risk Factors and Causes:
Multiparity.
Pre-eclampsia and eclampsia.
Hypertension.
Abdominal Trauma.
Multiple Pregnancy.
Polyhydramnios.
Previous abruption.
Folate and vitamin B12 deficiency.
Sudden decompression of the uterus, i.e. following rupture of membranes in cases of polyhydramnios.
Smoking.
Illegal drug abuse (especially cocaine use)
Increasing maternal age.
Prolonged rupture of membranes.
Vulval or cervical infection.
Tumours.

Abruption arises from bleeding into the deciduas basalis of the placenta, which results in the formation of a haematoma and increase in hydrostatic pressure, leading to separation of the placenta. The resultant haematoma may be small and self-limited, or may continue to dissect through the decidual layers. However, the bleeding may be in whole or in part concealed, if the placenta does not reach the margin of the placenta and cervix.

Clinical Presentation:
Vaginal bleeding (not always present).
Continuous abdominal pain.
Uterine Contractions (not always present).
Tenderness on palpation of the uterus.
The uterus may be feel hard or ‘woody’.
Fetal distress (bradycardia, tachycardia or absent heart rate).
Reduced fetal movements.
Hypovolaemic shock, which may be disproportionate to the amount of blood loss visible.

Placental abruption has been divided into three classifications:
I. Mild – This is not recognised clinically before delivery and is usually diagnosed by the presence of a retroplacental clot.
II. Intermediate – The classical signs of abruption are present, but the fetus is still alive.
III. The fetus is dead and coagulopathy may be present.

Complications:
Fetal death.
Acute renal failure.
Anaemia.
Sepsis.
Prematurity.
Fetal hypoxia.
Disseminated intravascular coagulation (DIC).





http://www.patient.co.uk/showdoc/40000210/
Medforth, J., Battersby, S., Evans, M., Marsh, B. and Walker, A. (2006) Oxford Handbook of Midwifery. Oxford: Oxford University Press.