*Warning: If you think  you may be experiencing a placental abruption please call an ambulance. 

A placental abruption is a very uncommon complication that normally occurs in the third trimester. It occurs when the placenta prematurely separates from the wall of the uterus. Most of the time placental abruption presents with moderate to heavy bright vaginal bleeding, and some severe abdominal pain and premature labour or even frank labour. Sometimes only the severe abdominal pain and premature labour is experienced before the placental bleeding is witnessed after the birth of the baby. The blood originates from the maternal blood vessels, but extra stress is placed on the baby’s well-being, because of compromise of placental function, and the speed of the uterine contractions.

In placental abruption foetal mortality may be 20%.

Characteristically if the placental bleeding is severe then a rapid labour process is inevitable. Given the potential compromise to the baby, often an emergency caesarean section is required. Maternal blood loss can be heavy enough to require blood transfusion, complex surgical procedures, or even occasionally an emergency hysterectomy.

Risk factors for abruption include pre-eclampsia, smoking, advanced maternal age, placental failure, blood thinning agents and previous caesarean section. The abruption when it recently has occurred is not seen on ultrasound examination as it has the same echogenicity as the placenta itself.

If vaginal bleeding greater than one tablespoon occurs in the presence of sudden abdominal pain, then immediately call the hospital delivery suite and your obstetrician.

If more than half a cup of blood is lost, call an ambulance. Do not stop to pack anything, do not delay for any cause.


This blog post was provided by obstetrician Dr Guy Skinner.