Red Degeneration of Fibroid

Red (carneous) degeneration is haemorrhagic infarction of a fibroid, caused by venous thrombosis and loss of blood supply when the fibroid outgrows its vessels. It is most common in pregnancy, mostly in the second trimester.

• The fibroid turns dark red like raw meat.
• It resolves with supportive care in 4 to 7 days in most women.
• It can mimic an acute abdomen, abruption and appendicitis.

Acute localised abdominal pain over a known or new fibroid, low-grade fever, nausea, vomiting and tenderness on palpation.

• Localised tender mass, a mildly raised temperature and a mild leucocytosis.
• Differential diagnosis: placental abruption, preterm labour, appendicitis, ovarian torsion, pyelonephritis, fibroid torsion, uterine rupture.
• Complications: preterm labour, premature rupture of membranes, infection, persistent pain, and repeat degeneration.

Diagnosis is clinical, supported by ultrasound, after exclusion of abruption and appendicitis.

• Clinical diagnosis in a woman with a known fibroid in pregnancy or after delivery.
• Ultrasound showing a heterogeneous fibroid, tender on probe pressure, with normal placenta and fetal wellbeing.
• MRI if the diagnosis is unclear and the woman is stable.
• Full blood count; C-reactive protein; urinalysis; cardiotocography after 26 weeks.
• Exclude abruption and appendicitis.

Treat with rest, hydration and analgesia, and monitor the pregnancy.

• Supportive: bed rest, hydration with oral fluids or IV crystalloid, heat to the abdomen, fetal monitoring, reassurance that pain eases in about a week.
• Pharmacological: paracetamol 1 g oral or IV 6-hourly (maximum 4 g in 24 hours). Severe pain: morphine 2.5 to 5 mg IV titrated every 5 minutes, or tramadol 50 mg oral 6-hourly (maximum 400 mg in 24 hours). Ibuprofen 400 mg oral 8-hourly with food (maximum 1.2 g in 24 hours) in non-pregnant women; in pregnancy limit it to 48 hours before 28 weeks and avoid it from 28 weeks. Antibiotics only when infection is suspected: amoxicillin-clavulanate 625 mg oral 8-hourly for 5 to 7 days.
• Procedures: none in most cases; myomectomy or hysterectomy for failure of analgesia, fever with peritonism, or non-pregnant women with persistent pain.
• Special groups: in pregnancy give corticosteroids for lung maturity (dexamethasone 6 mg IM 12-hourly for 4 doses) if preterm labour occurs between 24 and 34 weeks. In renal impairment avoid ibuprofen.
• Red flags: regular contractions, vaginal bleeding, fever above 38 degrees Celsius, peritonism, rapidly rising pain.
• Follow-up: review daily while admitted; ultrasound for growth every 4 weeks in pregnancy; postnatal review at 6 weeks.