Pyelonephritis

BANFF, ALTA -- Women with a history of vesicoureteral reflux should be closely monitored during pregnancy for signs and symptoms of pyelonephritis, Dr. Connie DiMarco recommended at the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.

In her retrospective study, 83 pregnant women with a history of vesicoureteral reflux (VUR) had a 14.5% incidence of pyelonephritis during pregnancy, compared with only a 0.7% incidence among 12,481 pregnant women without a history of VUR.

Interestingly, the profile organisms responsible for the pyelonephritis were slightly different if the woman had a history of VUR, said Dr. DiMarco of the Mayo Medical Center, Rochester, Minn.

Escherichia coli was the predominant pathogen causing the kidney infections among all pyelonephritis patients. However, E. coli infection was less common in those with a history of VUR (90% vs. 58%) than in those without VUR.

Dr. DiMarco speculated that the discrepancy in the role of E. coli as the culprit pathogen could have something to do with the use of prophylactic antibiotics among women with a history of VUR. "Perhaps [the use of antibiotics is] selecting out more resistant bugs," she said in an interview.

Among women with pyelonephritis, 44% of those with a history of VUR had taken prophylactic antibiotics, compared with none of those who did not have VUR.

Previous studies have suggested that rates of gestational pyelonephritis vary from 6% to 22% among women with VUR, compared with 1% - 5% among women without VUR. This difference in risk is probably related to the higher incidence of renal scarring among women with a history of VUR (83% vs. 0%).

The scarring renders women more susceptible to developing pyelonephritis.

Yet even when scarring is not present, women with a history of reflux are at increased risk for pyelonephritis during pregnancy, and that's true regardless of whether they've had ureterocystostomy performed.

Having a history of VUR could theoretically increase the risk of pregnancy-induced hypertension, she said.

Yet in this study, among all patients with pyelonephritis, the presence or absence of VUR did not seem to have much of a bearing on the risk of preterm delivery.

The average gestational age at delivery was 39 weeks among control patients with pyelonephritis, compared with 38 weeks among case patients with pyelonephritis.

COPYRIGHT 2002 International Medical News Group
COPYRIGHT 2002 Gale Group