Placental abruption
Placental abruption (also known as abruptio placentae) is a complication of pregnancy, wherein the placental lining has separated from the uterus of the mother. It is the most common pathological cause of late pregnancy bleeding. In humans, it refers to the abnormal separation after 20 weeks of gestation and prior to birth. It occurs in 1% of pregnancies world wide with a fetal mortality rate of 20–40% depending on the degree of separation. Placental abruption is also a significant contributor to maternal mortality.
The heart rate of the fetus can be associated with the severity.[1]
Lasting effects
On the mother:
- A large loss of blood or hemorrhage may require blood transfusions and intensive care after delivery. 'APH weakens for PPH to kill'.
- The uterus may not contract properly after delivery so the mother may need medication to help her uterus contract.
- The mother may have problems with blood clotting for a few days.
- If the mother's blood does not clot (particularly during a caesarean section) and too many transfusions could put the mother into disseminated intravascular coagulation (DIC) due to increased thromboplastin, the doctor may consider a hysterectomy.
- A severe case of shock may affect other organs, such as the liver, kidney, and pituitary gland. Diffuse cortical necrosis in the kidney is a serious and often fatal complication.
- In some cases where the abruption is high up in the uterus, or is slight, there is no bleeding, though extreme pain is felt and reported.
On the baby:
- If a large amount of the placenta separates from the uterus, the baby will probably be in distress until delivery and may die in utero, thus resulting in a stillbirth.
- The baby may be premature and need to be placed in the newborn intensive care unit. He or she might have problems with breathing and feeding.
- If the baby is in distress in the uterus, he or she may have a low level of oxygen in the blood after birth.
- The newborn may have low blood pressure or a low blood count.
- If the separation is severe enough, the baby could suffer brain damage or die before or shortly after birth.
Symptoms
- contractions that don't stop (and may follow one another so rapidly as to seem continuous)
- pain in the uterus
- tenderness in the abdomen
- vaginal bleeding (sometimes)
- uterus may be disproportionately enlarged
- pallor
Clinical Manifestation
- Class 0: asymptomatic. Diagnosis is made retrospectively by finding an organized blood clot or a depressed area on a delivered placenta.
- Class 1: mild and represents approximately 48% of all cases. Characteristics include the following:
- No vaginal bleeding to mild vaginal bleeding
- Slightly tender uterus
- Normal maternal BP and heart rate
- No coagulopathy
- No fetal distress
- Class 2: moderate and represents approximately 27% of all cases. Characteristics include the following:
- No vaginal bleeding to moderate vaginal bleeding
- Moderate-to-severe uterine tenderness with possible tetanic contractions
- Maternal tachycardia with orthostatic changes in BP and heart rate
- Fetal distress
- Hypofibrinogenemia (i.e., 50–250 mg/dL)
- Class 3: severe and represents approximately 24% of all cases. Characteristics include the following:
- No vaginal bleeding to heavy vaginal bleeding
- Very painful tetanic uterus
- Maternal shock
- Hypofibrinogenemia (i.e., <150 mg/dL)
- Coagulopathy
- Fetal death
Pathophysiology
Trauma, hypertension, or coagulopathy contributes to the avulsion of the anchoring placental villi from the expanding lower uterine segment, which in turn, leads to bleeding into the decidua basalis. This can push the placenta away from the uterus and cause further bleeding. Bleeding through the vagina, called overt or external bleeding, occurs 80% of the time, though sometimes the blood will pool behind the placenta, known as concealed or internal placental abruption.
Women may present with vaginal bleeding, abdominal or back pain, abnormal or premature contractions, fetal distress or death.
Abruptions are classified according to severity in the following manner:
- Grade 0: Asymptomatic and only diagnosed through post partum examination of the placenta.
- Grade 1: The mother may have vaginal bleeding with mild uterine tenderness or tetany, but there is no distress of mother or fetus.
- Grade 2: The mother is symptomatic but not in shock. There is some evidence of fetal distress can be found with fetal heart rate monitoring.
- Grade 3: Severe bleeding (which may be occult) leads to maternal shock and fetal death. There may be maternal disseminated intravascular coagulation. Blood may force its way through the uterine wall into the serosa, a condition known as Couvelaire uterus.
Risk factors
- Maternal hypertension is a factor in 44% of all abruptions.
- Maternal smoking is associated with up to 90% increased risk.[2]
- Maternal drinking of alcoholic beverages within a year before conception and during pregnancy can increase the risk by a factor 3 to 4 [3]
- Maternal trauma, such as motor vehicle accidents, assaults, falls or nosocomial infection.
- Short umbilical cord
- Prolonged rupture of membranes (>24 hours)
- Retroplacental fibromyoma
- Maternal age: pregnant women who are younger than 20 or older than 35 are at greater risk.
- Previous abruption: Women who have had an abruption in previous pregnancies are at greater risk.
- some infections are also diagnosed as a cause
- cocaine intoxication [4]
The risk of placental abruption can be reduced by maintaining a good diet including taking folic acid, regular sleep patterns and correction of pregnancy-induced hypertension.
Intervention
Placental abruption is suspected when a pregnant mother has sudden localized abdominal pain with or without bleeding. The fundus may be monitored because a rising fundus can indicate bleeding. An ultrasound may be used to rule out placenta praevia but is not diagnostic for abruption. The mother may be given Rhogam if she is Rh negative.
Treatment depends on the amount of blood loss and the status of the fetus. If the fetus is less than 36 weeks and neither mother or fetus is in any distress, then they may simply be monitored in hospital until a change in condition or fetal maturity whichever comes first.
Immediate delivery of the fetus may be indicated if the fetus is mature or if the fetus or mother is in distress. Blood volume replacement to maintain blood pressure and blood plasma replacement to maintain fibrinogen levels may be needed. Vaginal birth is usually preferred over caesarean section unless there is fetal distress. Caesarean section is contraindicated in cases of disseminated intravascular coagulation. Patient should be monitored for 7 days for PPH. Excessive bleeding from uterus may necessitate hysterectomy if family size is completed.
References
External links