How common is a placental abruption?
Placental abruption is relatively rare, with slight separation occurring in only about one of 150 pregnancies (that's less than 1 percent). More severe separation happens in only about one out of 800 to 1,600 deliveries. It almost always occurs in the second half of the pregnancy, most often in the third trimester.
It is thought that an abnormal blood supply in the uterus or placenta may play a role, but the cause of the suspected abnormality isn't clear. Some of the known causes of placental abruption include: Abdominal trauma – an injury to the pregnant woman's abdomen may tear the placenta from the wall of the uterus.
- The signs and symptoms of placental abruption include one or more of the following:
- Vaginal bleeding (although about 20% of cases will have no bleeding)
- Uterine tenderness.
- Rapid contractions.
- Abdominal pain.
- Fetal heart rate abnormalities.
- Waiting until your body is ready to deliver the placenta can take a little time, from about 10 minutes to up to an hour (this might sound like a long time but you will have been saying hello to your baby so the time goes by very quickly).
- Diagnosis. If your health care provider suspects placental abruption, he or she will do a physical exam to check for uterine tenderness or rigidity. During an ultrasound, high-frequency sound waves create an image of your uterus on a monitor.
Placental abruption can cause life-threatening problems for both mother and baby. For the mother, placental abruption can lead to: Shock due to blood loss. Blood clotting problems (disseminated intravascular coagulation)
- Fetal distress is an uncommon complication of labor. It typically occurs when the fetus has not been receiving enough oxygen. Fetal distress may occur when the pregnancy lasts too long (postmaturity) or when complications of pregnancy or labor occur.
- About 1 in 100 pregnant women (1 percent) have placental abruption. It usually happens in the third trimester, but it can happen any time after 20 weeks of pregnancy. Mild cases may cause few problems. An abruption is mild if only a very small part of the placenta separates from the uterus wall.
- A doctor diagnoses placental abruption by conducting a physical exam, and often by performing an ultrasound. You doctor may also conduct blood tests and fetal monitoring. Your doctor may suspect placental abruption, but they can only truly diagnose it after you've given birth.
Updated: 28th October 2019