Puerperal septic pelvic thrombophlebitis: incidence and response to heparin therapy.
OBJECTIVE: Before the availability of modern imaging studies the diagnosis of septic pelvic thrombophlebitis causing prolonged puerperal fever was difficult to confirm without surgical exploration. With the use of computed tomography infection-related pelvic phlebitis can now be confirmed, and this study was designed to determine its incidence after delivery. We also designed a randomized clinical trial to evaluate the efficacy of heparin added to antimicrobial therapy for treatment of women with septic phlebitis. STUDY DESIGN: We studied women who had pelvic infection and fever that persisted after 5 days despite adequate antimicrobial therapy with clindamycin, gentamicin, and ampicillin. After giving consent study participants underwent abdominopelvic computed tomographic imaging. Women with pelvic thrombophlebitis were randomly assigned to 1 of 2 management schemes that included continuation of antimicrobial therapy, either alone or with the addition of heparin, until the temperature was </=37.5 degrees C for 48 hours. RESULTS: During the 3-year study period 44,922 women were delivered at Parkland Hospital; among these 8535 (19%) were delivered by the cesarean route. There were 69 women who met criteria for prolonged infection, and 15 (22%) of these were found to have septic pelvic thrombophlebitis. Four had infection after vaginal delivery and 11 had been delivered by the cesarean route. Of 14 women randomly assigned to therapy, 8 were assigned to receive continued antimicrobial therapy without the addition of heparin and the other 6 were assigned to receive heparin therapy in addition to the antimicrobial agents. According to an intent-to-treat analysis there was no significant difference between the responses of women with pelvic infection who were and were not given heparin therapy. Specifically, women not given heparin were febrile for 140 +/- 39 hours compared with 134 +/- 65 hours for women who received heparin (P =.83). Duration of hospitalization was also similar between the 2 groups at 10.6 +/- 1.9 days for those with thrombosis who were given antimicrobial agents alone and 11.3 +/- 1.2 days for women who also received heparin (P >.5). The 54 women with persistent fever but without computed tomographic evidence of septic pelvic thrombophlebitis were hospitalized for a mean of 12.0 +/- 4.1 days, compared with 10.9 +/- 2.9 days for women in whom thrombosis was diagnosed (P =.14). These women were followed up for >/=3 months post partum and none showed evidence of reinfection, embolic episodes, or postphlebitic syndrome. CONCLUSIONS: The overall incidence of septic pelvic thrombophlebitis was 1:3000 deliveries. The incidence was about 1:9000 after vaginal delivery and 1:800 after cesarean section. Women given heparin in addition to antimicrobial therapy for septic thrombophlebitis did not have better outcomes than did those for whom antimicrobial therapy alone was continued. These results also do not support the common empiric practice of heparin treatment for women with persistent postpartum infection.