Placental Abruption Definition

Placental abruption, or abruptio placentae, is a pregnancy complication in which the placenta peels away from the lining of the uterus prior to delivery.  Its severity depends on whether the separation is partial or complete. The abruption hampers the oxygen and nutrient supply to the baby, sometimes causing heavy bleeding in the placenta and uterus.

It generally occurs between the 28th and 40th pregnancy weeks (third trimester) but can also occur during the middle or later parts of the second trimester (after the 20th week). 

Types of Placental Abruption

It is most commonly classified depending on the nature of bleeding into two types:

·         Revealed Placental Abruption:  Causes vaginal bleeding (external or overt bleeding) that helps with early detection of the complication. Around 80% of the total cases lead to external bleeding.

·         Concealed Placental Abruption (Internal Placental Abruption): Sometimes, there is no vaginal bleeding as the blood gets trapped, pooling behind the placenta. It can only be detected only through an ultrasound. 

·          Classification according to severity:

·         Grade 0: Asymptomatic in nature, usually diagnosed by examining the placenta after delivery 

·         Grade 1: Characterized by vaginal bleeding, accompanied by mild uterine tenderness and tetany in the mother; however, there is no maternal or fetal distress.

·         Grade 2: Characterized by various symptoms in the mother; however, does not cause maternal shock. Some evidence of fetal distress may be found by fetal heart rate assessment.

·         Grade 3: Causes severe bleeding (concealed or revealed), which may lead to fatal complications of maternal shock and even fetal death.

What are the Signs and Symptoms of Placental Abruption?

Placental abruption may or may not be painful and may even remain asymptomatic in rare cases. Apart from vaginal bleeding (in revealed abruption), classic signs include:

·         Back pain 

·         Abdominal cramping and pain

·         Abdominal tenderness

·         Rapid uterine contractions ^[7]

·         Uterine tenderness

·         Pallor

·         Disproportionately enlarged uterus

·         Nausea and vomiting

·         Restlessness

It is advisable to contact one’s health care provider immediately in case she experiences one or more of these symptoms.

What Causes Placental Abruption?

The exact causes responsible for the abruption still remain unknown. Researches show a possible genetic association that increases the risk of an abruption. According to experts it may occur due to:

·         A severe abdominal trauma or injury (from a fall or a car accident) 

·         Rapid loss of amniotic fluid (fluid that surrounds the baby in the uterus – can occur after the delivery of a first twin) 

What are the Risk Factors of Placental Abruption?

·         Thrombophilias (blood clotting disorder)

·         Being over 35 years of age

·         High blood pressure (pregnancy-induced hypertension)

·         Diabetes (gestational or pre-existing)

·         Carrying twins or triplets

·         Smoking 

·         Lifting heavy objects

·         Cocaine abuse by the mother before or during pregnancy

·         Excessive alcohol consumption

·         History of placental abruption in some previous pregnancy

·         Any uterine infection

·         Having a short umbilical cord

·         Increased uterine distention (due to multiple pregnancy or extremely high amniotic fluid levels)

·         Premature rupture of membranes or PROM water breaking before the 37th week of pregnancy) 

·         Uterine fibroids

·         Uterine rupture

·         Oligohydramnios

·         Preeclampsia 

·         Chorioamnionitis

Placental Abruption Prevention

Prevention is not possible in most cases due to its unknown etiology. However, avoiding the risk factors, such as alcohol, smoking and cocaine, may reduce the chances of a placental abruption. According experts, women who follow a healthy diet and a proper exercise routine before conceiving are less at risk of developing an abruption. Those suffering from high blood pressure or diabetes during pregnancy should consult their health care provider to assess the risk factors. 

Placental Abruption Diagnosis

The diagnostician may perform a physical examination to determine the uterine rigidity or tenderness. Various diagnostic tests can be used for confirming the diagnosis.

Abdominal Ultrasound

It helps doctors to detect any intra-amniotic clotting, separation or rounding of placental edges and abnormal thickening of the placenta which may indicate a placental abruption. However, an ultrasound test may not be enough to confirm the diagnosis.

Other diagnostic tests include:

·         Blood tests (complete blood count, platelet count, partial thromboplastin time, prothrombin time, fibrinogen level)

·         Fetal monitoring

·         Pelvic exam 

·         Vaginal ultrasound

Placental Abruption Differential Diagnosis 

·         Labor with bloody show

·         Pre-term labor

·         Acute appendicitis

·         Vaginal trauma

·         Hemorrhagic Shock

·         Disseminated Intravascular Coagulation

·         Pregnancy Trauma

·         Placenta Previa

·         Ovarian Torsion

·         Ovarian Cysts

·         Preeclampsia

·         Ectopic Pregnancy

Placental Abruption Complications

Maternal Complications

·         Hypovolemic shock (shock due to excessive blood loss)

·         Disseminated intravascular coagulation (blood clotting problems) 

·         Necessity of a blood transfusion

·         Kidney failure

Fetal Complications

·         Oxygen and nutrients deprivation

·         Brain damage and cerebral palsy due to reduced oxygen supply 

·         Low blood count or low blood pressure

·         Premature birth

·         Growth problems and learning issues

·         Stillbirth

The baby may have a mild jaundice after birth, which usually goes away automatically within a few days or weeks.

Placental Abruption Treatment and Management

The treatment generally depends on the severity of the complication and stage of pregnancy in which it is diagnosed.

Managing Mild Placental Abruption (Partial Separation)

In case of mild or chronic abruption between the 24th and 34th week, the doctors may put the patients on bed rest to prevent further aggravation. Regular monitoring tests, like ultrasounds, are also performed to assess fetal growth. A small tear in the placenta may heal on its own without leading to any serious pregnancy complications.

If one develops a mild placental abruption at full term or during the later stages of the third trimester, the doctor may recommend a c-section birth or inducing labor.

Managing Severe Placental Abruption (Complete Separation)

A severe abruption may require immediate delivery of the baby to avoid further complications. Doctors often recommend a c-section birth.  Corticosteroid medications may be used to accelerate the development of the lungs and other organs of the baby in case of an emergency delivery.

A blood transfusion may be necessary in some rare cases where the mother suffers from heavy blood loss. Sometimes, it causes severe post-delivery hemorrhage which may call for an emergency hysterectomy (uterus removal) surgery. It helps with the management of the bleeding but also eliminates the possibility of conceiving ever again.

Placental Abruption Outcome

The outcome depends on the degree of placental separation from the uterus as well as the efficacy of the treatment. Severe placental abruption is associated with a considerable maternal and fetal mortality rate.

What are the Chances of Recurrence in Future Pregnancies?

The chance of getting a placental abruption in a future pregnancy is 1 in 25, which increases to 1 in 5 in women with history of abruption in two earlier pregnancies.

Placental Abruption Incidence

It has been recorded in around 46,731 pregnancies with the incidence statistics being 6.2 in every 1,000 pregnancies.