Revealed Placental Abruption

Revealed placental abruption is separation of the placenta in which blood escapes through the cervix and is visible as vaginal bleeding. It is the commoner form of abruption, and the visible loss usually, but not always, reflects the true loss. It matters because it ranges from a small marginal bleed with a healthy fetus to massive haemorrhage with fetal death, and it can still cause coagulopathy.

• Risk factors: hypertension and preeclampsia, previous abruption, smoking, cocaine, abdominal trauma, preterm rupture of membranes, thrombophilia.
• Bleeding is typically dark and accompanied by pain, unlike the painless bleeding of previa.
• Mild marginal abruption can be managed expectantly with close observation.

Women have vaginal bleeding with abdominal pain, a tense tender uterus with frequent contractions, and a fetus that may show distress. Shock is in keeping with the visible loss.

• Dark red bleeding with clots.
• Pain and uterine irritability.
• Differential diagnosis: placenta previa, vasa previa, cervical lesion, show in labour, uterine rupture, preterm labour, genital tract trauma.
• Complications: haemorrhage, shock, disseminated intravascular coagulation, acute kidney injury, preterm birth, fetal distress or death, postpartum haemorrhage, hysterectomy, maternal death.

The diagnosis is clinical, with ultrasound used to exclude previa.

• Pulse, blood pressure, uterine tone and tenderness, fetal heart by Doppler and cardiotocography; speculum examination for the amount and source of bleeding once previa is excluded.
• Ultrasound for placental site, retroplacental or marginal clot, fetal viability and liquor.
• Haemoglobin, platelets, fibrinogen, prothrombin time, activated partial thromboplastin time, creatinine, group and cross-match 2 to 4 units; bedside clotting test; Kleihauer test in RhD negative women.
• Urine output hourly in moderate or severe disease.

The principle is resuscitation, assessment of the fetus and a plan that ranges from expectant care for small bleeds to prompt delivery for severe disease.

• Supportive: two large-bore cannulae; oxygen 10 to 15 L/minute if shocked; Ringer's lactate 1 to 2 litres rapidly; left lateral position; urinary catheter with hourly output in severe disease; continuous cardiotocography for a live fetus; admit for at least 48 hours even if the bleeding is light.
• Pharmacological: transfuse packed red cells for haemoglobin below 7 g/dL or shock, with fresh frozen plasma 15 mL/kg and cryoprecipitate 10 units (or fibrinogen concentrate 2 to 4 g) for fibrinogen below 2 g/L, and platelets one adult dose for platelets below 50 x 10^9/L; tranexamic acid 1 g IV over 10 minutes, repeated once after 30 minutes if bleeding continues; betamethasone 12 mg IM twice, 24 hours apart, between 24 and 34 weeks and 6 days; magnesium sulphate 4 g IV over 20 minutes then 1 g per hour until delivery for 24 hours at most before 32 weeks; oxytocin 10 IU IM at birth then infusion of 20 IU in 1 litre sodium chloride 0.9 percent at 125 mL per hour for 4 hours; carboprost 250 micrograms IM every 15 minutes (maximum 8 doses) for atony, avoided in asthma; labetalol 20 mg IV then 40 mg, 80 mg and 80 mg at 10 minute intervals (maximum 220 mg) for blood pressure 160/110 mmHg or more.
• Procedures: expectant care for a mild abruption below 34 weeks with a stable mother and normal cardiotocography, with delivery at 37 weeks; emergency caesarean section for fetal distress or maternal instability; vaginal delivery with amniotomy and oxytocin (2 mU/minute doubling every 30 minutes to 32 mU/minute) for fetal death with a stable mother; balloon tamponade, compression sutures, uterine artery ligation or hysterectomy for uncontrolled bleeding.
• Special groups: RhD negative women give anti-D immunoglobulin 500 IU IM within 72 hours, increased by 125 IU for each 1 mL of fetal red cells above 4 mL; women who decline transfusion need cell salvage and tranexamic acid.
• Red flags: heavy bleeding, shock, rising fundal height, fibrinogen below 2 g/L, platelets below 50 x 10^9/L, fetal bradycardia or absent heart rate.
• Follow-up: cardiotocography twice daily for 48 hours; growth scans every 2 weeks; ferrous sulphate 200 mg oral 8-hourly for 3 months; antenatal review weekly from 34 weeks.