Written by Dr.M.D.Mazumdar, MD

Placental Abruption is also called 'Abruptio Placentae'.

It is a type of Antepartum Haemorrhage. Other causes of antepartum hemorrhage are Placenta previa, cervical erosion, cervical polyp, cervical carcinoma and varicose veins of the vagina or vulva.

Placental abruption or Abruptio Placentae is a condition in which there is premature separation of the placenta from the uterine wall. It is more common in a normally situated placenta in the upper part of the uterus before delivery of the baby, or sometimes even before labor begins.

Bleeding occurs between the placenta and the uterine wall and can either trickle out between the amniotic membranes or collect as a blood clot between the placenta and the uterine wall.

The blood clot gradually increases in size, separating the placenta more and more from its attachment to the uterine wall. This can be highly dangerous since it decreases the blood flow to the fetus.

The incidence of placental abruption is 0.42%. It tends to recur in 8.8% of patients.

Clinical Types of Placental Abruption

There are three clinical types of placental abruption.

• Revealed type: In this type of placental abruption, the bleeding that occurs behind the placenta (retroplacental haemorrhage) trickles down between the membranes and the uterine walls to be revealed at the vaginal opening. Since there is no collection of blood behind the placenta, separation of the placenta from the uterus is usually less than in the other types. This is a mild type of placental abruption.

• Concealed Type: The blood fails to trickle down and collects between the placenta and the uterine wall. The enlarging blood clot further dissects out the placenta from its bed and placental separation can occur over a large area. This is a serious type of placental abruption.

• Mixed Type: In this type, part of the blood trickles down and part collects behind the placenta. Like the concealed type, this is also a dangerous type of placental abruption as the blood clot continues to dissect out the placenta from the placental bed.

Causes of Placental Abruption

• Premature Rupture of Membranes: Premature rupture of the membranes or rupture of the bag of waters before the time of delivery can lead to acute infection inside the uterus. This infection is believed to be a leading cause of placental abruption.

• Toxaemia of Pregnancy: The high blood pressure associated with pre-eclamptic toxaemia (PET) or toxaemia of pregnancy is frequently associated with placental abruption.

• Chronic Hypertension: High blood pressure present even before the start of pregnancy can also cause placental abruption.

• Traumatic: Mechanical trauma to the placenta such as in forceful external cephalic version (attempting to reposition the fetus in a breech presentation), a fall on the abdomen, a short cord that pulls on the placenta during labor pains or overstimulation of the uterus during induction of labour are different types of mechanical trauma which can lead to abruptio placentae.

• Unknown Cause: Sometimes no cause can be identified.

Signs and Symptoms of Placental Abruption

The signs and symptoms varies depending on whether the placental abruption is of the revealed or concealed type.

Revealed Placental Abruption

• Vaginal bleeding: The bleeding is mild to moderate. The blood is blackish red in colour and trickles continuously from the vagina.

• Pain: Pain may be mild or absent. But most patients complain of a general discomfort over the abdomen.

• Symptoms of other diseases: Symptoms of other disease processes like PET, diabetes or essential hypertension may be present.

• On Examination: Localised pain may be present over the uterus at the site of implantation of the placenta. The uterus otherwise feels normal in size and on palpation.

  The fetus is usually healthy. The foetal heart beat is normal.

Concealed Placental Abruption

• Vaginal bleeding: There may be no bleeding in the concealed type but in the mixed type, a little trickle of blood may be seen.

• Pain: There is acute, agonising pain over the abdomen. The pain usually occurs suddenly and may be severe enough to immobilise the patient.

• Symptoms of other diseases: Symptoms of other disease processes like PET, diabetes or essential hypertension may be present.

• Shock: Shock is an outstanding feature of the concealed type of placental abruption. The patient may be unconscious when brought to the hospital and show all the signs and symptoms of acute blood loss like a thin, thready pulse, low blood pressure, cold, clammy arms and legs etc.

• On Examination: On examination, the patient appears pale and anaemic. The uterus is tense, tender and hard. Muscle gaurd over the uterus makes palpation difficult.

  The fetal parts are not easily felt and the fetal heart may not be heard as there may be death of the foetus in the uterus.

Treatment of Placental Abruption

Treatment of placental abruption is again different in the different types - revealed and concealed. All patients with a history of vaginal bleeding should always be investigated by ultrasonography and treatment depends to a great deal on the USG report.

Revealed Placental Abruption

• If bleeding is slight:If the patient is stable and USG shows minimal retroplacental bleeding with a healthy immature foetus - conservative treatment with hospital admission, complete bed rest and careful monitoring is done. A cesarian section is done once the fetus reaches maturity.

  If the patient has come in labour, she is allowed to proceed under intensive monitoring.

  If the foetus is a mature term foetus, cesarian section is done as early as possible to minimize blood loss.

• If bleeding is considerable:If it is believed that the bleeding is enough to compromise the life of the mother, a cesarian section is done, regardless of whether the foetus is mature or not. With improvement in perinatal care, even a fetus as young as 24 weeks have been known to survive.

Concealed Placental Abruption

If the patient has come in shock, she is promptly resuscitated with IV fluids, blood transfusion etc. An emergency cesarian section is done as early as possible to cut down on the blood loss.

If the patient is in labor and is expected to deliver almost immediately, she is allowed to proceed, keeping her ready for a cesarian section.

In most patients, the fetus is dead at the time of treatment.

Cesarian hysterectomy In some patients with concealed type of placental abruption, the retroplacental clot may be very large. There may even be bleeding into the muscle and blood vessels of the uterus, causing injury and damage. Blood can leak out of the damaged vessels to collect in the muscles, causing edema and necrosis of the uterine muscles. The damage may be enough to cause minute bruise and ecchymoses on the surface of the uterus. This is called a 'Couvelaire Uterus'.

The Couvelaire uterus sometimes is too damaged to contract and control bleeding after delivery of the baby. A cesarian hysterectomy (removal of the uterus) becomes necessary to control the haemorrhage.

Mortality due to Placental Abruption: The incidence of maternal mortality is about 3.9% and mainly caused by severe anemia (61.6%) and puerperal infections (7.9%). Foetal mortality is 37.77%.

Also Read-

• Progress of Normal Pregnancy.
• When is labor called Normal Labor?
• Vaginal Discharge with Itching .
• Symptoms of Pregnancy - morning sickness, sore breasts, stretch marks etc.