Placental Abruption

Definition/diagnostic criteria Placental abruption, clinically referred to as abruptio placentae, is a condition characterised by the premature separation of a normally implanted placenta from the uterine wall before the delivery of the foetus. The diagnostic criteria are primarily based on clinical findings, including vaginal bleeding, uterine tenderness and contractions, along with evidence of foetal distress. Ultrasound may not be definitive for diagnosis but can help exclude other causes of symptoms.

Epidemiology Placental abruption occurs in approximately 1% of pregnancies and is a significant cause of maternal and foetal morbidity and mortality. Risk factors include hypertension, preeclampsia, previous abruption, advanced maternal age, multiparity, smoking and cocaine use. The incidence is higher in women with a low socio-economic status and those of African-Caribbean descent.

Diagnosis
Clinical features: The classic presentation includes vaginal bleeding, abdominal pain, uterine tenderness and hypertonicity, and signs of foetal distress. However, clinical manifestations can vary significantly depending on the severity and location of the abruption. In some cases, bleeding may be concealed and pain may be the only symptom.

Investigations: Laboratory tests may show evidence of anaemia or disseminated intravascular coagulation (DIC) in severe cases. Ultrasound can be helpful in excluding other causes of bleeding but is not reliable for diagnosing placental abruption as the sensitivity is low. Cardiotocography (CTG) is used to monitor foetal wellbeing.

Treatment The management of placental abruption depends on the severity of the abruption, the gestational age, and the condition of the mother and foetus. For minor abruptions in a stable patient, expectant management with close monitoring may be considered. In cases of significant abruption, or if the foetus is in distress, immediate delivery is usually required, typically via caesarean section. Supportive care includes blood transfusions if necessary, and the administration of corticosteroids if the foetus is preterm to help mature the lungs. Analgesia and tocolysis may be considered in specific situations.

Prognosis The prognosis depends on the severity of the abruption, the gestational age at onset, and the speed of diagnosis and intervention. There can be significant morbidity for both the mother and the foetus. Maternal complications include haemorrhage, shock, renal failure and DIC. Foetal complications can range from growth restriction and preterm birth to stillbirth. The perinatal mortality rate is significantly increased in cases of placental abruption.