Vulvar haematoma

Definition

• A vulvar haematoma is a collection of blood in the vulva, which is supplied mainly by the pudendal artery.
• Injury to the labial branches of the internal pudendal artery readily initiates a haematoma; the source of bleeding is often a branch of the pudendal artery.

Occurrence & epidemiology

Epidemiology

• In obstetrics, vulvar haematoma is a recognised complication, although reported frequencies vary widely; outside obstetrics it is rare.

Aetiopathogenesis

Aetiology and risk factors

• During labour, they result from direct injury such as birth lacerations, episiotomy or instrumental vaginal birth, or indirectly from extensive stretching of the birth canal.
• Risk factors include hypertension, multiple pregnancy, a large baby, clotting abnormalities, episiotomy, vulvovaginal varicosities and first pregnancy; spontaneous haematomas typically follow precipitate labour or a prolonged second stage.
• Outside obstetrics, they mostly result from trauma such as straddle injuries or assault; rarely they occur after intercourse or spontaneously from rupture of the iliac or pudendal artery.

Clinical features

• The most common leading symptom is pain, after birth usually within 24 hours, together with vulvar swelling.
• After birth, the haematoma is detected at a median of about 6 hours; rarely it becomes apparent only days later.
• Possible consequences are voiding difficulties up to urinary retention, anaemia and haemodynamically significant haemorrhage, and tissue necrosis.

Diagnosis

Typical imaging findings

• Clinical finding: One labium is distended into a tensely swollen, blue-livid mass that distorts the vulva asymmetrically. The overlying skin is shiny and taut; fresh blood is seen at the perineum.

• Clinically, there is a tender, fluctuant swelling, because bleeding into the vulva is largely restricted only by Colles fascia and the urogenital diaphragm.
• Ultrasound helps to distinguish it from an abscess or cyst, and CT angiography can show the bleeding vessel and active extravasation; there is no gold standard for imaging.

Keep learning in the app

Further reading (selection)

1. Delayed presentation of a non-resorbing postpartum vulvar hematoma: A case report (Case Rep Womens Health 2023, PubMed Central)
2. Computed Tomography Findings in Non-Obstetric Vulvar Hematoma: A Case Report (J Educ Teach Emerg Med 2024, PubMed Central)
3. Postpartum spontaneous vulvar hematoma as a cause of maternal near miss: a case report and review of the literature (J Med Case Rep 2022, PubMed Central)

Cross-references