Superficial Thrombophlebitis in Pregnancy

Superficial thrombophlebitis in pregnancy is clot and inflammation in a superficial vein, usually a varicose vein or a vein used for an IV cannula. Pregnancy raises the risk through venous stasis and hypercoagulability. It matters because some are accompanied by deep vein thrombosis, and clot near the saphenofemoral junction can extend into deep veins.

• Risk factors: varicose veins, previous thrombosis, obesity, immobility, IV cannula, thrombophilia, infection.
• Higher risk if the clot is above the knee, 5 cm or more long, or within 3 cm of the saphenofemoral junction.
• Septic phlebitis follows cannula infection.

Women have a tender, red, hard cord along a superficial vein with local warmth and sometimes low-grade fever. The limb is not usually swollen.

• Vein feels like a firm cord.
• Spreading redness and pus suggest septic phlebitis.
• Differential diagnosis: deep vein thrombosis, cellulitis, lymphangitis, erythema nodosum, panniculitis, vasculitis.
• Complications: extension into deep veins, pulmonary embolism, septic thrombophlebitis, recurrence, chronic venous disease.

The diagnosis is clinical, with duplex ultrasound to exclude deep vein thrombosis and measure the clot.

• Compression duplex ultrasound of the whole leg: clot length, distance from the saphenofemoral junction, deep vein involvement.
• Full blood count and temperature chart if infection is suspected.
• Culture of any pus or cannula tip.
• Thrombophilia screening for recurrent or extensive disease.

The principle is symptom relief for short clots and prophylactic anticoagulation for longer or high risk clots.

• Supportive: warm compresses 3 to 4 times daily; elevation; walking; graduated compression stockings of 20 to 30 mmHg; remove any IV cannula; avoid prolonged standing.
• Pharmacological: paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours); enoxaparin 40 mg subcutaneous daily for 45 days for clot 5 cm or longer or above the knee, and therapeutic enoxaparin 1 mg/kg subcutaneous 12-hourly for clot within 3 cm of the saphenofemoral junction; avoid NSAIDs after 20 weeks; flucloxacillin 500 mg to 1 g oral or IV 6-hourly for 7 days for septic phlebitis; topical heparinoid gel twice daily to the area.
• Procedures: surgical removal of an infected vein segment or ligation at the saphenofemoral junction for septic or extending clot.
• Special groups: renal impairment uses enoxaparin 20 mg subcutaneous daily or unfractionated heparin; women with deep vein thrombosis follow full dose treatment.
• Red flags: leg swelling, breathlessness, chest pain, fever above 38 degrees Celsius, spreading redness, pus.
• Follow-up: review at 1 week; repeat ultrasound at 7 to 10 days if the clot is near the junction; review at 6 weeks postpartum.