After giving birth to your baby, the placenta naturally separates from the wall of the uterus as it is no longer needed. However, this sometimes occurs before your baby is born. This premature separation of the placenta from the uterus is called placental abruption, and it can be a life-threatening emergency.
Placental abruption occurs in approximately 1 in 150 pregnancies. It can occur at any time during the pregnancy but usually occurs in the last 12 weeks before birth. There are certain risk factors that make this more likely: high blood pressure or preeclampsia, older maternal age, having had children already, preterm rupture of membranes, abdominal trauma such as a fall or domestic abuse, cocaine use, and smoking.
Common signs of placental abruption include abdominal pain and vaginal bleeding. Occasionally, pain will be the only sign as the bleeding is concealed in the uterus and does not pass out of the vagina. In smaller abruptions (where a smaller portion of the placenta separates), a woman may only have bleeding without any pain. When the bleeding is large in amount, a woman may appear very ill and go into shock.
If an obstetric provider is worried about abruption, he or she can do an ultrasound to look for an area where the placenta has separated or to visualize a blood clot. An ultrasound is not perfect, however, but is usually adequate at diagnosing larger abruptions. Blood work is often done as well to see if a woman has a low blood count or has other abnormalities. The baby’s heart rate will be monitored as well to ensure they are doing well.
Women with small abruptions who are stable and are very preterm may be managed expectantly. That is, they will not be delivered and will be closely watched instead. This may be done with the woman either at home or in the hospital, depending on the individual situation.
However, if the bleeding is severe or the mother or baby appears in distress, delivery will usually be recommended. A vaginal delivery is not out of the question, but a C-section may be needed depending on the circumstances, and sometimes this is done emergently. A blood transfusion may also be needed if a lot of blood was lost.
Reviewed by Dr. Jen Lincoln, April 2020
- A placental abruption is when the placenta prematurely separates from the wall of the uterus before the baby is delivered.
- Signs of placental abruption include abdominal pain and bleeding.
- If the bleeding is severe or the mother or baby is in distress, delivery will be recommended.