Septic pelvic thrombophlebitis complicates 1 in 2000 to 3000 deliveries, is more common following cesarean delivery (1 in 400), and is preceded by bacterial infection in the placental implantation site or the uterine incision. As shown in Figure 22-1, infection may extend along venous routes and cause thrombophlebitis. The ovarian veins may then become involved. Twenty-five percent of women with septic pelvic thrombophlebitis have a clot extending into the inferior vena cava.
FIGURE 22-1 Routes of extension of septic pelvic thrombophlebitis. Any pelvic vessel and the inferior vena cava may be involved as shown on the left. The clot in the right common iliac vein extends from the uterine and internal iliac veins and into the inferior vena cava. (Reproduced, with permission, from Cunningham FG, Leveno KJ, Bloom SL, et al (eds). Williams Obstetrics. 23rd ed. New York, NY: McGraw-Hill; 2010.)
CLINICAL PRESENTATION
Women with septic pelvic thrombophlebitis have hectic fever spikes although they usually are asymptomatic except for chills. This clinical picture is aptly termed enigmatic fever. Typically these women are already receiving antimicrobials for postpartum metritis but have not become afebrile despite 5 days or so of such therapy. In some women, the cardinal symptom of ovarian vein thrombophlebitis is pain manifest on the second or third postpartum day with a tender mass palpable just beyond the uterine cornu. Diagnosis of septic pelvic thrombophlebitis is made by clinical suspicion and either pelvic computed tomography or magnetic resonance imaging to identify thrombosis and perivascular edema.
MANAGEMENT
Those women who develop septic pelvic thrombophlebitis and are already receiving antimicrobials for postpartum endometritis (see Chapter 21) should have this therapy continued. These women show slow but gradual clinical improvement over an additional 5 to 7 days when such antimicrobial therapy is continued. Concurrent heparin therapy has not proven to be beneficial.
For further reading in Williams Obstetrics, 23rd ed.,
see Chapter 31, “Puerperal Infection.”