Introduction to Placental Abruption

A placenta is a temporary organ that develops during pregnancy inside a mother’s womb by attaching to the uterine wall. The main function of a placenta is to nourish the fetus. The umbilical cord, which connects the placenta to the infant, supplies oxygen and nutrients while inside the uterus.

The detachment of the placenta from the uterus before the baby is born is called placental abruption – and they require immediate medical attention. Most of them occur before the thirty-seventh week of gestation.

According to studies, placental abruption is a leading cause of maternal morbidity and perinatal mortality.¹

A patient experiencing placental abruption is at risk for:

• Hemorrhages
• Disseminated intravascular coagulopathy
• Renal failure
• Sheehan syndrome
• Postpartum pituitary gland necrosis

Patients may need a blood transfusion or hysterectomy to avoid these complications.

So when you’re performing an abdominal assessment on a patient, make sure you look for:

1. A hard abdomen
2. Decreasing blood pressure
3. Increasing heart rate

If they tick these boxes, the patient is most likely having a placental abruption.

Placental Abruption Pathophysiology

The placenta is the fetus’s source of oxygen, nutrients, and a way to excrete waste products. It diffuses oxygen and nutrients to the fetus, while simultaneously removing carbon dioxide and other wastes. If it becomes separated from the mother’s circulatory system, these vital functions are interrupted, and the fetus dies.

As a result, the fetus becomes hypoxic (suffering from a lack of oxygen), which is potentially fatal.

Placental abruption occurs when the mother’s vessels tear away from the placenta, and bleeding occurs between the uterine wall and the maternal side of the placenta. As the blood accumulates, it pushes the uterine wall and placenta apart. 

There are three types of placental abruptions: partial, complete, or concealed. All three result in severe pain and significant bleeding in the uterus.With partial placental abruption, only a portion of the placenta is sloughed off the uterine wall, possibly underneath or around the area of separation.

Placental Abruption Causes

These factors can cause placental abruption and make a mother more likely to give birth prematurely:

• Trauma caused by accidents, falls, blunt force, etc.
• Hypertension
• Stimulant use (especially cocaine)
• History of previous abruptions
• Smoking

Signs and Symptoms of Placental Abruption

Internal bleeding is the most prominent manifestation of placental abruption. The extent of bleeding depends on how much the placenta has separated from the uterine wall. This blood loss is usually internal, so external signs may not be evident.

Since not much fluid is left in the blood vessels during placental abruption, enough bleeding can lead to hypovolemic shock. 

Pain may be one of the most recognizable signs of placental abruption, as some patients report a pain level that is off the charts. Others include:

• Late decelerations (along with a sudden decrease in fetal heart rate and signs of bradycardia)
• Dark red vaginal bleeding
• Severe continuous abdominal pain
• Rigid and tender uterus
• Decreased hemoglobin and hematocrit (H&H) 
• Hypovolemic shock
• Abnormal fetal heart patterns
• Uterine tachysystole (with the fetus)

Drugs Used for Placental Abruption Treatment

Corticosteroids may be administered to speed up the development of the baby’s lungs if the mother is less than thirty-four weeks pregnant. They are also given if a health care provider finds all of the following:

• The pregnancy is late preterm (thirty-four to thirty-six weeks). 
• The mother has not previously received corticosteroids during this pregnancy and has no contraindications to their use. 
• There is a high risk of delivery in the late preterm period.

Placental Abruption Nursing Interventions

• Prepare the patient for a cesarean birth.
• Monitor fetal vitals consistently.
• Perform IV access and blood draw for blood transfusion (if needed) 
• Assess for signs of hypovolemic shock Pallor, tachycardia, and/or hypotension.

Sources

¹ https://pubmed.ncbi.nlm.nih.gov/21241259 

https://www.ncbi.nlm.nih.gov/books/NBK482335/ 

https://www.merckmanuals.com/professional/gynecology-and-obstetrics/abnormalities-of-pregnancy/placental-abruption-abruptio-placentae