Placental abruption

Definition

Placental abruption is a condition in pregnancy in which the placenta prematurely separates from the uterine wall while the fetus is still in utero. While it is seen most often during the third trimester of pregnancy, especially during the labor process, the term can be applied from 20 weeks gestation through term. Severe bleeding, even hemorrhage, can result, putting both the mother and fetus at significant risk. It is also known as placenta abruptio and abruptio placentae.

Description

In most cases placental abruption occurs in a normally implanted placenta, one that is located high on the uterine wall. However, it can occur in tandem with placenta previa . In a normal vaginal delivery, the delivery of the placenta follows that of the neonate within about 30 minutes. Because the neonate has been born and is now breathing on his or her own, the separation of the placenta from the uterine wall causes no distress. In placental abruption, however, the premature separation of the placenta deprives the fetus of the oxygen, nutrients, and gas exchange taking place at the site of the separation. The cost to the fetus depends on the degree and size of the separation. The risk to the mother depends on the amount of blood lost, and the change in circulating blood volume and its accompanying decreased tissue perfusion.

Placental abruption occurs in about one in 120 deliveries. Severe abruption leading to fetal death occurs in about one in 420 deliveries. Cocaine use increases the risk of abruption by increasing vasoconstriction, and about 10% of mothers using cocaine in the third trimester succumb to placental abruption.

Causes and symptoms

The causes of abruption are not fully understood, but it appears that it may be the end result of a series of fetalmaternal vascular abnormalities. Impaired blood vessel integrity and suppressed immune function may lie at the core of the development of abruption. Some of the factors leading to placental abruption include:

• Trauma. An abdominal blow, such as that incurred during an automobile accident, may cause abruption. Mothers experiencing a severe blow to the abdomen, with subsequent uterine contractions, should be monitored for about 24 hours, even in the absence of vaginal bleeding. This is because there could be a delay in symptoms. Observation of the mother should also include fetal monitoring to assure fetal well-being.
• Maternal hypertension . Mothers who have either chronic high blood pressure or hypertension induced by pregnancy are at increased risk of abruption.
• Maternal age. Placental abruption is seen more often in older women. However, it is unclear whether the advanced age or the increased likelihood of previous gestations is the primary factor.
• Uterine and umbilical cord abnormalities, such as a short cord or a uterine myoma at the placental implantation site.
• Placental abnormalities resulting in poor implantation.
• Cigarette smoking. As the number of cigarettes per day increases, so does the risk of abruption. This higher risk may be because of the harmful effect of nicotine on blood vessel integrity.
• Previous placental abruption. The risk of recurrence may be almost 17%.

The classic symptoms of abruption include sharp abdominal pain , rigid abdomen, vaginal bleeding, uterine contractions, and uterine tenderness. However, these signs are not always present. About 10% of women may have no vaginal bleeding. This is because the blood is pooling behind the placenta that has detached in the center. If the abruption occurred in tandem with labor contraction, and if the abruption is mild or moderate, the pain of labor contractions may mask the underlying abdominal pain and uterine tenderness of the abruption. This variability of symptoms emphasizes the need for careful diagnosis.

Diagnosis

Diagnosis of placental abruption, especially when mild or moderate, can be elusive. A thorough maternal history can play a significant role in identifying mothers at increased risk. Severity of abruption cannot be determined only from the volume of visible blood lost, as concealed hemorrhage may be taking place. Pain may be primarily in the back instead of abdominal. It may be sharp and severe, or dull and intermittent. It may be accompanied by nausea and vomiting. The uterine contraction pattern tends to be low in amplitude but high in frequency. If the uterus and abdomen are rigid, external monitoring or contractions may be inaccurate. Uterine tenderness may be localized to the site of detachment, but may also present as generalized. Unfortunately, ultrasound is not very reliable in establishing the presence of placental abruption. Blood work may be done to check on the presence of an abnormal clotting process. Diagnosis may become the piecing together of a puzzle of symptoms, with the experienced practitioner being more likely to solve the puzzle.

Placental abruption is categorized into four degrees of separation. These are:

• Grade 0. Abruption was diagnosed after delivery, upon inspection of the placenta. The placenta will show a small area of clotting on the side of maternal attachment. No other visible maternal or fetal signs of abruption were present.
• Grade 1. Some separation occurred with some vaginal bleeding and changes in maternal vital signs . No fetal distress was noted.
• Grade 2. Moderate separation, fetal distress, uterus is tender to touch.
• Grade 3. Extreme separation; without emergency intervention mother and fetus are at risk of shock , hemorrhage, or death.

Separation may be partial, with vaginal bleeding; partial without vaginal bleeding (known as concealed hemorrhage); complete separation, with vaginal bleeding (likely hemorrhage); or complete separation with concealed hemorrhage. Concealed bleeding is very dangerous because the lack of vaginal bleeding masks the true severity of the condition. Then, if the mother goes into shock, it may be unexpected and result in a poor outcome. If the placenta detached in the center, concealed bleeding is more likely to occur. Blood may seep into the uterine wall and result in a condition called couvelaire uterus, which is characterized by a hard uterus, no bleeding, and no signs of impending maternal shock. Shock results from the blood loss into the uterine tissue.

Treatment

A mother with suspected placental abruption needs to be admitted to the hospital. As complete a history as possible should be taken. If the mother is in crisis, family or friends may be able to assist with the history. Blood work to check for clotting disorders is done, as placental abruption may be accompanied by disseminated intravascular coagulation (DIC) which can lead to massive hemorrhage. Intravenous (IV) fluids and blood transfusions may be necessary to replace blood lost. Oxygen may be administered. Continuous fetal monitoring is done to assess for signs of fetal distress. Decreased maternal urine output indicates a compromised blood volume with poor tissue perfusion. The severity of the abruption determines the course of treatment. If a small separation has occurred, the pregnancy may be maintained as long as the mother is stable and the fetus does not show signs of distress. If the separation is a grade 0 or 1, and the fetus is near term, a vaginal delivery may be attempted. A separation of grade 3 or 4 necessitates delivery even if the fetus is not sufficiently mature, as the separation has compromised adequate nutrients and oxygen from reaching the fetus, and the accompanying blood lost has put the mother's well-being at risk. If DIC has begun, prompt evacuation of the uterus of the fetus and the placenta can allow for a positive prognosis for the mother. However, surgery poses great risk to the mother because of her compromised ability to clot. Severe hemorrhage, organ failure, and death could occur.

KEY TERMS

Disseminated intravascular coagulation —DIC is a serious medical complication in which the mother's blood no longer clots in the usual manner because of extreme loss of blood. Bruising is visible on the skin, and blood can seep from sites of IV insertion. This is a medical emergency, as it can quickly lead to massive hemorrhage.

Gestation —The age of the fetus in weeks since conception.

Myoma —A benign fibroid tumor of the uterine muscle.

Placenta previa —Placenta previa is a condition of pregnancy in which the placenta, which normally is implanted high on the uterine wall, is instead implanted near the cervical opening. As the uterus begins to change in preparation for labor and delivery, the force exerted on the placenta can cause it to tear, depriving the fetus of nutrition and oxygen, and putting the mother at risk of hemorrhage.

Prognosis

Prognosis is dependent on many factors, such as the frequent monitoring of vital signs, the degree of separation, amount of blood lost, such preexisting fetal complications as growth retardation and congenital abnormalities, gestational age of the fetus, any permanent organ damage to the mother, and degree of oxygen deprivation. Prompt diagnosis enhances chances for a successful outcome.

Health care team roles

Nurses play a significant role in obtaining a full and accurate patient history. Questions should include maternal symptoms, time elapsed since symptoms began, presence and quality of pain (sharp, dull, constant, intermittent), bleeding (amount and color), and any actions taken, such as medication for pain or use of tampons.

Prevention

While most factors contributing to abruption are not preventable, cigarette smoking, cocaine use, and seat belt use with proper placement are important areas on which to focus during prenatal care . Identifying a mother at high risk and having a management plan in place can expedite diagnosis, especially if the mother arrives through the emergency department in crisis; and result in a more successful outcome for both mother and baby.

Resources

BOOKS

Creasy, Robert K., and Robert Resnik. Maternal-Fetal Medicine. Philadelphia: W.B. Saunders Company, 1999.

Feinbloom, Richard I. Pregnancy, Birth, and the Early Months. Cambridge, MA: Perseus Publishing, 2000.

Pillitteri, Adele. Maternal & Child Health Nursing. 3rd ed. Philadelphia: Lippincott, 1999.

PERIODICALS

Abu-Heija, A. T., M. F. Jallad, and F. Abukteish. "Maternal and Perinatal Outcome of Pregnancies After the Age of 45." Journal of Obstetrical and Gynecologic Research (February 2000): 27-30.

Bunai, Y., et al. "Fetal Death From Abruptio Placentae Associated With Incorrect Use of a Seatbelt." Journal of Forensic and Medical Pathology (September 2000): 207-209.

ORGANIZATIONS

American College of Obstetricians and Gynecologists. 409 12th St., S.W., PO Box 96920, Washington, D.C. 20090-6920. <http://www.acog.com>.

Esther Csapo Rastegari, R.N., B.S.N., Ed.M.

Placental Abruption

Definition

Placental abruption is a condition in pregnancy in which the placenta prematurely separates from the uterine wall while the fetus is still in utero. While it is seen most often during the third trimester of pregnancy, especially during the labor process, the term can be applied from 20 weeks gestation through term. Severe bleeding, even hemorrhage, can result, putting both the mother and fetus at significant risk. It is also known as placenta abruptio and abruptio placentae.

Description

In most cases placental abruption occurs in a normally implanted placenta, one that is located high on the uterine wall. However, it can occur in tandem with placenta previa. In a normal vaginal delivery, the delivery of the placenta follows that of the neonate within about 30 minutes. Because the neonate has been born and is now breathing on his or her own, the separation of the placenta from the uterine wall causes no distress. In placental abruption, however, the premature separation of the placenta deprives the fetus of the oxygen, nutrients, and gas exchange taking place at the site of the separation. The cost to the fetus depends on the degree and size of the separation. The risk to the mother depends on the amount of blood lost, the subsequent change in circulating blood volume, and its accompanying decrease in tissue perfusion.

Placental abruption occurs in about one in 120 deliveries. Severe abruption leading to fetal death occurs in about one in 420 deliveries. Cocaine use increases the risk of abruption by increasing vasoconstriction, and about 10% of mothers using cocaine in the third trimester succumb to placental abruption.

Causes and symptoms

The causes of abruption are not fully understood, but it appears that it may be the end result of a series of fetal-maternal vascular abnormalities. Impaired blood vessel integrity and suppressed immune function may lie at the core of the development of abruption. Some of the factors leading to placental abruption include:

• Trauma. An abdominal blow, such as that incurred during an automobile accident may cause abruption. Mothers experiencing a severe blow to the abdomen, with subsequent uterine contractions, should be monitored for about 24 hours, even in the absence of vaginal bleeding. This is because there could be a delay in symptoms. Observation of the mother should also include fetal monitoring to assure fetal well-being.
• Maternal hypertension. Mothers who have either chronic high blood pressure or hypertension induced by pregnancy are at increased risk of abruption.
• Maternal age. Placental abruption is seen more often in older women. However, it is unclear whether the advanced age or the increased likelihood of previous gestations is the primary factor.
• Uterine and umbilical cord abnormalities, such as a short cord or a uterine myoma at the placental implantation site.
• Placental abnormalities resulting in poor implantation.
• Cigarette smoking. As the number of cigarettes per day increases, so does the risk of abruption. This may be because of the harmful effect of nicotine on blood vessel integrity.
• Previous placental abruption. The risk of recurrence may be almost 17%.

The classic symptoms of abruption include sharp abdominal pain, rigid abdomen, vaginal bleeding, uterine contractions, and uterine tenderness. However, these signs are not always present. About 10% of women may have no vaginal bleeding. This is because the blood is pooling behind the placenta that has detached in the center. If the abruption occurred in tandem with labor contraction, and if the abruption is mild or moderate, the pain of labor contractions may mask the underlying abdominal pain and uterine tenderness of the abruption. This variability of symptoms emphasizes the need for careful diagnosis.

Diagnosis

Diagnosis of placental abruption, especially when mild or moderate, can be elusive. A thorough maternal history can play a significant role in identifying mothers at increased risk. Severity of abruption cannot be determined only from the volume of visible blood lost, as concealed hemorrhage may be taking place. Pain may be primarily in the back instead of abdominal. It may be sharp and severe, or dull and intermittent. It may be accompanied by nausea and vomiting. The uterine contraction pattern tends to be low in amplitude but high in frequency. If the uterus and abdomen are rigid, external monitoring or contractions may be inaccurate. Uterine tenderness may be localized to the site of detachment, but may also present as generalized. Unfortunately, ultrasound is not very reliable in establishing the presence of placental abruption. Blood work may be done to check on the presence of an abnormal clotting process. Diagnosis may become the piecing together of a puzzle of symptoms, with the experienced practitioner being more likely to solve the puzzle.

Placental abruption is categorized into four degrees of separation. These are:

• Grade 0. Abruption was diagnosed after delivery, upon inspection of the placenta. The placenta will show a small area of clotting on the side of maternal attachment. No other visible maternal or fetal signs of abruption were present.
• Grade 1. Some separation occurred with some vaginal bleeding and changes in maternal vital signs. No fetal distress was noted.
• Grade 2. Moderate separation, fetal distress, uterus is tender to touch.
• Grade 3. Extreme separation; without emergency intervention mother and fetus are at risk of shock, hemorrhage, or death.

Separation may be partial, with vaginal bleeding; partial without vaginal bleeding (known as concealed hemorrhage); complete separation, with vaginal bleeding (likely hemorrhage); or complete separation with concealed hemorrhage. Concealed bleeding is very dangerous because the lack of vaginal bleeding masks the true severity of the condition. Then, if the mother goes into shock, it may be unexpected and result in a poor outcome. If the placenta detached in the center, concealed bleeding is more likely to occur. Blood may seep into the uterine wall and result in a condition called couvelaire uterus, which is characterized by a hard uterus, no bleeding, and no signs of impending maternal shock. Shock results from the blood loss into the uterine tissue.

Treatment

A mother with suspected placental abruption needs to be admitted to the hospital. As complete a history as possible should be taken. If the mother is in crisis, family or friends may be able to assist with the history. Blood work to check for clotting disorders is done, as placental abruption may be accompanied by disseminated intravascular coagulation (DIC) which can lead to massive hemorrhage. Intravenous (IV) fluids and blood transfusions may be necessary to replace blood lost. Oxygen may be administered. Continuous fetal monitoring is done to assess for signs of fetal distress. Decreased maternal urine output indicates a compromised blood volume with poor tissue perfusion. The severity of the abruption determines the course of treatment. If a small separation has occurred, the pregnancy may be maintained as long as the mother is stable and the fetus does not show signs of distress. If the separation is a grade 0 or 1, and the fetus is near term, a vaginal delivery may be attempted. A separation of grade 3 or 4 necessitates delivery even if the fetus is not sufficiently mature, as the separation has compromised adequate nutrients and oxygen from reaching the fetus, and the accompanying blood lost has put the mother's well-being at risk. If DIC has begun, prompt evacuation of the uterus of the fetus and the placenta can allow for a positive prognosis for the mother. However, surgery poses great risk to the mother because of her compromised ability to clot. Severe hemorrhage, organ failure, and death could occur.

Prognosis

Prognosis is dependent on many factors such as the frequent monitoring of vital signs, the degree of separation, amount of blood lost, preexisting fetal complications such as growth retardation and congenital abnormalities, gestational age of the fetus, any permanent organ damage to the mother, and degree of oxygen deprivation. Prompt diagnosis enhances chances for a successful outcome.

KEY TERMS

Disseminated intravascular coagulation— DIC is a serious medical complication in which the mother's blood no longer clots in the usual manner because of extreme loss of blood. Bruising is visible on the skin, and blood can seep from sites of IV insertion. This is a medical emergency, as it can quickly lead to massive hemorrhage.

Gestation— The age of the fetus in weeks since conception.

Myoma— A benign fibroid tumor of the uterine muscle.

Placenta previa— Placenta previa is a condition of pregnancy in which the placenta, which normally is implanted high on the uterine wall, is instead implanted near the cervical opening. As the uterus begins to change in preparation for labor and delivery, the force exerted on the placenta can cause it to tear, depriving the fetus of nutrition and oxygen, and putting the mother at risk of hemorrhage.

Health care team roles

Nurses play a significant role in obtaining a full and accurate patient history. Questions should include maternal symptoms, time elapsed since symptoms began, presence and quality of pain (sharp, dull, constant, intermittent), bleeding (amount and color), and any actions taken, such as medication for pain or use of tampons.

Prevention

While most factors contributing to abruption are not preventable, cigarette smoking, cocaine use, and seat belt use with proper placement are important areas on which to focus during prenatal care. Identifying a mother at high risk and having a management plan in place can expedite diagnosis, especially if the mother arrives through the emergency department in crisis, and result in a more successful outcome for both mother and baby.

Resources

BOOKS

Creasy, Robert K., and Robert Resnik. Maternal-Fetal Medicine. Philadelphia: W.B. Saunders Company, 1999.

Feinbloom, Richard I. Pregnancy, Birth, and the Early Months. Cambridge, MA: Perseus Publishing, 2000.

Pillitteri, Adele. Maternal & Child Health Nursing. 3rd ed. Philadelphia: Lippincott, 1999.

PERIODICALS

Abu-Heija, A. T., M. F. Jallad, and F. Abukteish. "Maternal and Perinatal Outcome of Pregnancies After the Age of 45." Journal of Obstetrical and Gynecologic Research (February 2000): 27-30.

Bunai, Y., et al. "Fetal Death From Abruptio Placentae Associated With Incorrect Use of a Seatbelt." Journal of Forensic and Medical Pathology (September 2000): 207-209.

ORGANIZATIONS

American College of Obstetricians and Gynecologists. 409 12th St., S.W., PO Box 96920, Washington, D.C. 20090-6920. 〈http://www.acog.com〉.

Placental Abruption

Definition

Placental abruption occurs when the placenta separates from the wall of the uterus prior to the birth of the baby. This can result in severe, uncontrollable bleeding (hemorrhage).

Description

The uterus is the muscular organ that contains the developing baby during pregnancy. The lowest segment of the uterus is a narrowed portion called the cervix. This cervix has an opening (the os) that leads into the vagina, or birth canal. The placenta is the organ that attaches to the wall of the uterus during pregnancy. The placenta allows nutrients and oxygen from the mother's blood circulation to pass into the developing baby (the fetus) via the umbilical cord.

During labor, the muscles of the uterus contract repeatedly. This allows the cervix to begin to grow thinner (called effacement) and more open (dilatation). Eventually, the cervix will become completely effaced and dilated, and the baby can leave the uterus and enter the birth canal. Under normal circumstances, the baby will go through the mother's vagina during birth.

During a normal labor and delivery, the baby is born first. Several minutes to 30 minutes later, the placenta separates from the wall of the uterus and is delivered. This sequence is necessary because the baby relies on the placenta to provide oxygen until he or she begins to breathe independently.

Placental abruption occurs when the placenta separates from the uterus before the birth of the baby. Placental abruption occurs in about one out of every 200 deliveries. African-American and Latin-American women have a greater risk of this complication than do Caucasian women. It was once believed that the risk of placental abruption increased in women who gave birth to many children, but this association is still being researched.

Causes and symptoms

The cause of placental abruption is unknown. However, a number of risk factors have been identified. These factors include:

• older age of the mother
• history of placental abruption during a previous pregnancy
• high blood pressure
• certain disease states (diabetes, collagen vascular diseases)
• the presence of a type of uterine tumor called a leiomyoma
• twins, triplets, or other multiple pregnancies
• cigarette smoking
• heavy alcohol use
• cocaine use
• malformations of the uterus
• malformations of the placenta
• injury to the abdomen (as might occur in a car accident)

Symptoms of placental abruption include bleeding from the vagina, severe pain in the abdomen or back, and tenderness of the uterus. Depending on the severity of the bleeding, the mother may experience a drop in blood pressure, followed by symptoms of organ failure as her organs are deprived of oxygen. Sometimes, there is no visible vaginal bleeding. Instead, the bleeding is said to be "concealed." In this case, the bleeding is trapped behind the placenta, or there may be bleeding into the muscle of the uterus. Many patients will have abnormal contractions of the uterus, particularly extremely hard, prolonged contractions. Placental abruption can be total (in which case the fetus will almost always die in the uterus), or partial.

Placental abruption can also cause a very serious complication called consumptive coagulopathy. A series of reactions begin that involve the elements of the blood responsible for clotting. These clotting elements are bound together and used up by these reactions. This increases the risk of uncontrollable bleeding and may contribute to severe bleeding from the uterus, as well as causing bleeding from other locations (nose, urinary tract, etc.).

Placental abruption is risky for both the mother and the fetus. It is dangerous for the mother because of blood loss, loss of clotting ability, and oxygen deprivation to her organs (especially the kidneys and heart). This condition is dangerous for the fetus because of oxygen deprivation, too, since the mother's blood is the fetus' only source of oxygen. Because the abrupting placenta is attached to the umbilical cord, and the umbilical cord is an extension of the fetus' circulatory system, the fetus is also at risk of hemorrhaging. The fetus may die from these stresses, or may be born with damage due to oxygen deprivation. If the abruption occurs well before the baby was due to be delivered, early delivery may cause the baby to suffer complications of premature birth.

Diagnosis

Diagnosis of placental abruption relies heavily on the patient's report of her symptoms and a physical examination performed by a health care provider. Ultrasound can sometimes be used to diagnose an abruption, but there is a high rate of missed or incorrect diagnoses associated with this tool when used for this purpose. Blood will be taken from the mother and tested to evaluate the possibility of life-threatening problems with the mother's clotting system.

Treatment

The first line of treatment for placental abruption involves replacing the mother's lost blood with blood transfusions and fluids given through a needle in a vein. Oxygen will be administered, usually by a mask or through tubes leading to the nose. When the placental separation is severe, treatment may require prompt delivery of the baby. However, delivery may be delayed when the placental separation is not as severe, and when the fetus is too immature to insure a healthy baby if delivered. The baby is delivered vaginally when possible. However, a cesarean section may be performed to deliver the baby more quickly if the abruption is quite severe or if the baby is in distress.

Prognosis

The prognosis for cases of placental abruption varies, depending on the severity of the abruption. The risk of death for the mother ranges up to 5%, usually due to severe blood loss, heart failure, and kidney failure. In cases of severe abruption, 50-80% of all fetuses die. Among those who survive, nearly half will have lifelong problems due to oxygen deprivation in the uterus and premature birth.

Prevention

Some of the causes of placental abruption are preventable. These include cigarette smoking, alcohol abuse, and cocaine use. Other causes of abruption may not be avoidable, like diabetes or high blood pressure. These diseases should be carefully treated. Patients with conditions known to increase the risk of placental abruption should be carefully monitored for signs and symptoms of this complication.

Resources

ORGANIZATIONS

American College of Obstetricians and Gynecologists. 409 12th Street, S.W., P.O. Box 96920, Washington, DC 20090-6920.

KEY TERMS

Cesarean section— Delivery of a baby through an incision in the mother's abdomen, instead of through the vagina.

Labor— The process during which the uterus contracts, and the cervix opens to allow the passage of a baby into the vagina.

Placenta— The organ that provides oxygen and nutrition from the mother to the baby during pregnancy. The placenta is attached to the wall of the uterus and leads to the baby via the umbilical cord.

Umbilical cord— The blood vessels that allow the developing baby to receive nutrition and oxygen from its mother; the blood vessels also eliminate the baby's waste products. One end of the umbilical cord is attached to the placenta and the other end is attached to the baby's belly button (umbilicus).

Uterus— The muscular organ that contains the developing baby during pregnancy.

Vagina— The birth canal; the passage from the cervix of the uterus to the opening leading outside of a woman's body.

placental abruption n. see abruptio placentae.