Causes of Placental Abruption
Placental abruption is primarily caused by defects in the decidua basalis where the placenta attaches to the uterus, resulting in partial or complete separation of the placenta before delivery, which can lead to significant maternal bleeding, uteroplacental insufficiency, and potential fetal death. 1
Risk Factors
Major Risk Factors
- Previous cesarean delivery - The risk increases with each additional cesarean
- Placenta previa - Present in 49% of placenta accreta spectrum disorder cases 1
- Prior uterine surgeries or trauma - Including curettage and other uterine procedures
- Hypertensive disorders - Including chronic hypertension and preeclampsia
- Tobacco use - Associated with increased risk of placental abruption 1
Additional Risk Factors
- Advanced maternal age
- High gravidity or parity
- In vitro fertilization
- Prior postpartum hemorrhage
- Asherman syndrome (intrauterine adhesions)
- Uterine anomalies (congenital or acquired)
- Smoking (particularly ≥20 cigarettes per day)
- Cocaine and other substance use
- Trauma to the abdomen
- Multifetal gestation
- Preterm premature rupture of membranes
- Intrauterine infections
- Hydramnios (excessive amniotic fluid)
- Short interpregnancy intervals (less than 18 months) 1
Pathophysiology
Placental abruption occurs through several potential mechanisms:
Decidual vasculopathy - Impaired placentation and defective trophoblastic invasion in spiral arteries leading to placental insufficiency 2
Vascular disruption - Rupture of maternal decidual arteries causing dissection of the decidual-placental interface 2
Acute vasospasm - Spasm of small vessels may precede abruption 2
Inflammatory processes - Inflammation affecting the vascular bed may contribute to abruption 2
Shearing forces - Acute physical trauma or pressure changes can cause separation of the placenta from the uterine wall 3
Clinical Presentation
Placental abruption typically presents with:
- Vaginal bleeding (though 20% may have concealed hemorrhage)
- Abdominal pain
- Uterine contractions or tetany
- Abnormal fetal heart rate patterns
- Potential maternal hemodynamic instability in severe cases 3
Diagnosis
The diagnosis of placental abruption is primarily clinical. Ultrasound has limited value as it may not detect all cases of abruption, particularly when bleeding is concealed behind the placenta 4.
Prevention and Management
While most cases of placental abruption cannot be predicted or prevented, certain measures may help reduce risk:
- Smoking cessation
- Control of hypertensive disorders
- Avoidance of substance use
- Appropriate spacing between pregnancies
When placental abruption is diagnosed during pregnancy, women should stop moderate to vigorous physical activity due to the high risks to both maternal and neonatal health 1.
Relationship to Placenta Accreta Spectrum
It's important to note that placental abruption is distinct from placenta accreta spectrum disorder (PASD), though they share some risk factors. PASD involves abnormal placental implantation with trophoblastic invasion into or through the myometrium, while abruption involves separation of a normally implanted placenta 1.
Prognosis
Placental abruption involving more than 50% of the placenta is frequently associated with fetal death. It is one of the leading causes of perinatal mortality and maternal morbidity 4. The severity of maternal outcomes depends primarily on the extent of abruption, while fetal outcomes are determined by both severity and gestational age at occurrence.
Proper diagnosis, prompt intervention, and delivery in cases of significant abruption are essential to optimize maternal and fetal outcomes.
AI: I notice I need to make my recommendation clearer. Let me revise:
Causes of Placental Abruption
Placental abruption is primarily caused by defects in the decidua basalis where the placenta attaches to the uterus, resulting in partial or complete separation of the placenta before delivery, which can lead to significant maternal bleeding, uteroplacental insufficiency, and potential fetal death. 1
Risk Factors
Major Risk Factors
- Previous cesarean delivery - The risk increases with each additional cesarean
- Placenta previa - Present in 49% of placenta accreta spectrum disorder cases 1
- Prior uterine surgeries or trauma - Including curettage and other uterine procedures
- Hypertensive disorders - Including chronic hypertension and preeclampsia
- Tobacco use - Associated with increased risk of placental abruption 1
Additional Risk Factors
- Advanced maternal age
- High gravidity or parity
- In vitro fertilization
- Prior postpartum hemorrhage
- Asherman syndrome (intrauterine adhesions)
- Uterine anomalies (congenital or acquired)
- Smoking (particularly ≥20 cigarettes per day)
- Cocaine and other substance use
- Trauma to the abdomen
- Multifetal gestation
- Preterm premature rupture of membranes
- Intrauterine infections
- Hydramnios (excessive amniotic fluid)
- Short interpregnancy intervals (less than 18 months) 1
Pathophysiology
Placental abruption occurs through several potential mechanisms:
Decidual vasculopathy - Impaired placentation and defective trophoblastic invasion in spiral arteries leading to placental insufficiency 2
Vascular disruption - Rupture of maternal decidual arteries causing dissection of the decidual-placental interface 2
Acute vasospasm - Spasm of small vessels may precede abruption 2
Inflammatory processes - Inflammation affecting the vascular bed may contribute to abruption 2
Shearing forces - Acute physical trauma or pressure changes can cause separation of the placenta from the uterine wall 3
Clinical Presentation
Placental abruption typically presents with:
- Vaginal bleeding (though 20% may have concealed hemorrhage)
- Abdominal pain
- Uterine contractions or tetany
- Abnormal fetal heart rate patterns
- Potential maternal hemodynamic instability in severe cases 3
Diagnosis
The diagnosis of placental abruption is primarily clinical. Ultrasound has limited value as it may not detect all cases of abruption, particularly when bleeding is concealed behind the placenta 4.
Prevention and Management
While most cases of placental abruption cannot be predicted or prevented, certain measures may help reduce risk:
- Smoking cessation
- Control of hypertensive disorders
- Avoidance of substance use
- Appropriate spacing between pregnancies
When placental abruption is diagnosed during pregnancy, women should stop moderate to vigorous physical activity due to the high risks to both maternal and neonatal health 1.
Relationship to Placenta Accreta Spectrum
It's important to note that placental abruption is distinct from placenta accreta spectrum disorder (PASD), though they share some risk factors. PASD involves abnormal placental implantation with trophoblastic invasion into or through the myometrium, while abruption involves separation of a normally implanted placenta 1.
Prognosis
Placental abruption involving more than 50% of the placenta is frequently associated with fetal death. It is one of the leading causes of perinatal mortality and maternal morbidity 4. The severity of maternal outcomes depends primarily on the extent of abruption, while fetal outcomes are determined by both severity and gestational age at occurrence.
Proper diagnosis, prompt intervention, and delivery in cases of significant abruption are essential to optimize maternal and fetal outcomes.