Definition

Abruptio placentae, or placental abruption, is a condition where part or all of the placenta detaches from the uterine wall before the birth of the baby. This results in reduced oxygen and nutrient supply to the fetus and bleeding during delivery. It is a serious and emergency complication in pregnancy.

Placental abruption occurs in about 1 in 100 pregnancies. It usually happens suddenly, starting in the second trimester of pregnancy, with most cases occurring before 37 weeks of gestation.

Role of the Placenta in Pregnancy

The placenta is a temporary organ that develops in the uterus during pregnancy. Typically, it attaches to the upper or side part of the uterine cavity. The placenta provides oxygen-rich blood and nutrients to the fetus through the umbilical cord and removes the fetus's metabolic waste. Therefore, the placenta must remain well-attached to the uterine wall and be delivered only after the baby is born.

Classification of Placental Abruption

Based on how much of the placenta detaches from the uterine wall, placental abruption is classified into two types:

• Partial placental abruption: occurs when part of the placenta detaches from the uterine wall.
• Complete or total placental abruption: occurs when the entire placenta detaches from the uterine wall, often resulting in vaginal bleeding.

Based on whether vaginal bleeding is visible, placental abruption is classified into two types:

• Revealed placental abruptions: characterized by moderate to severe visible vaginal bleeding.
• Concealed placental abruptions: characterized by little or no visible vaginal bleeding, with blood trapped between the placenta and the uterine wall.

Based on severity, placental abruption is classified into several categories:

• Category 0: No symptoms; diagnosis is made by finding blood clots or concave areas on the delivered placenta.
• Category 1: Mild (48% of all cases); no signs of emergency in the fetus or mother.
• Category 2: Moderate (27% of all cases); signs of fetal distress appear.
• Category 3: Severe (24% of all cases); a very critical condition that can endanger the mother.

Categories 0 and 1 usually occur with partial placental abruption, while categories 2 and 3 are common with total placental abruption.

Causes

The exact cause of placental abruption is unknown. However, it is believed to occur when there is a disturbance in the blood vessels connecting the placenta and the mother's uterus. Conditions such as high blood pressure or certain drug use can cause uterine stretching. While the uterine muscle is elastic, the placenta is not as elastic. Thus, when the uterine tissue suddenly stretches, it can tear the placenta away from the uterine wall.

Risk Factor

Although the exact cause of placental abruption is unknown, several risk factors are associated with its occurrence. These factors include:

• Injury or trauma to the uterus (e.g., car accidents, abdominal falls)
• Maternal age over 35 years during pregnancy
• Twin pregnancies
• Hypertension or previous pregnancy-related hypertension
• Previous placental abruption
• Pregnancy complications such as uterine infection and preeclampsia
• Problems with the umbilical cord
• Excess or insufficient amniotic fluid
• Blood clotting disorders
• Premature rupture of membranes
• Smoking
• Narcotics and alcohol abuse during pregnancy

Symptoms

Symptoms of placental abruption usually appear in the last trimester of pregnancy and a few weeks before the estimated due date. These symptoms include:

• Vaginal bleeding, though some cases have no bleeding; 80% of placental abruption cases report bleeding as a symptom
• Abdominal pain
• Back pain
• Recurrent uterine contractions
• Fetal heart rate problems
• Decreased amniotic fluid
• Abnormal fetal growth
• Decreased fetal movement

Diagnosis

As with other conditions, the doctor will conduct a thorough examination to diagnose placental abruption. The doctor will perform an interview, a physical examination, and additional tests.

Medical Interview and Physical Examination

During the interview, the doctor may ask about:

• The first day of the last menstrual period to confirm gestational age.
• Main and accompanying complaints.
• History of previous placental abruption.
• History of abdominal trauma.
• History of certain drug use (e.g., cocaine) during pregnancy.
• History of other conditions like hypertension, diabetes, or blood clotting disorders.

The doctor will quickly check the patient's vital signs because placental abruption can be life-threatening in some cases. The doctor will then perform a physical examination to check the condition of the abdomen and vagina, although vaginal examinations are generally avoided if the patient is bleeding.

Diagnostic Tests

The doctor may also conduct diagnostic tests such as blood tests and ultrasounds if necessary. Blood tests confirm whether the patient has conditions like anemia, infection, blood clotting disorders, or decreased kidney function.

Ultrasound is used to assess the condition of the fetus, the amount of amniotic fluid, and whether the placenta has partially or completely detached. Ultrasound also helps rule out other conditions that can cause third-trimester bleeding. If delivery is planned, cardiotocography (CTG) will monitor fetal well-being and heart rate.

Management

Once the placenta is detached from the uterus, it cannot be reattached. The doctor will provide treatment based on the severity of the placental abruption, the gestational age, signs of fetal distress, and the amount of maternal bleeding.

If the bleeding is severe and life-threatening, the doctor will first stabilize the mother. The mother will be hospitalized, given IV fluids and oxygen, and closely monitored. The doctor will also address any other conditions exacerbating the placental abruption.

Gestational Age Less Than 37 Weeks

If the condition is mild and there are no signs of emergency in the mother or fetus, the mother and fetus will be monitored in the hospital. A crossmatch procedure will be done to check the mother's blood type in case a transfusion is needed later.

If the fetus is healthy and the bleeding stops in the hospital, the mother can return home and be given medication to help mature the fetus's lungs in case of early delivery. If the mother's and fetus's conditions do not improve and the bleeding is severe, the doctor will perform a termination of pregnancy or preterm delivery to save both the mother and fetus.

Gestational Age More Than 34 Weeks

If the fetus is alive and the condition is not severe, delivery may be an option. If there are signs of fetal distress, a cesarean section may be performed to save the fetus. The mother will receive a blood transfusion if there is significant bleeding. Both the mother and fetus will be closely monitored after the procedure.

Complications

Complications of placental abruption can affect both the mother and fetus.

Maternal Complications

• Shock due to significant blood loss
• Blood clotting issues
• Cesarean delivery
• Kidney failure
• In rare cases, a hysterectomy may be performed due to uncontrolled bleeding
• Maternal death

Fetal Complications

• Inadequate oxygen and nutrient supply
• Premature birth
• Abnormal fetal development
• Fetal death

Prevention

Since the exact cause of placental abruption is unknown, there is no definitive way to prevent it. However, you can reduce the risk by minimizing risk factors, such as:

• Avoiding smoking during pregnancy
• Avoiding alcohol and narcotic use
• Driving safely and carefully to avoid traffic accidents
• Attending regular antenatal check-ups
• Controlling blood pressure and blood sugar levels

When to See a Doctor?

You should see a doctor immediately if you experience vaginal bleeding during pregnancy. Visit the emergency room, and the doctor will provide initial care before an obstetrician takes appropriate action. Early treatment can help prevent serious complications from placental abruption.

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