Predictors of symptomatic urinary tract infection after 20 weeks' gestation.

OBJECTIVE

To identify predictors of symptomatic urinary tract infection (UTI) after 20 weeks' gestation.

STUDY

DESIGN

A retrospective cohort analysis was conducted of all deliveries at three North Carolina hospitals between 1990 and 1993. A total of 7403 deliveries remained after exclusions (pre-pregnancy diabetes, HIV-positive, structural urologic abnormalities, no prenatal care) and restrictions (black or white race, county of residence). Cystitis and pyelonephritis were identified by clinician diagnosis. Multiple logistic regression was conducted.

RESULTS

Prior UTIs (both before and earlier in pregnancy), nonprivate clinics, and a history of chlamydia (white women only) doubled the risk of symptomatic UTIs after 20 weeks' gestation. The strongest predictor of pyelonephritis was prior antenatal UTIs (adjusted incidence odds ratio = 5.3, 95% confidence interval of 2.6-11.0), followed by less education (< 12 years), a history of chlamydia, nonprivate clinics, illicit drug use, sickle cell hemoglobinopathy, and being unmarried.

CONCLUSION

Medical history and demographic factors predict cystitis and pyelonephritis after 20 weeks' gestation. Prospective studies of pyelonephritis predictors and screening strategies are warranted.