Publication:

Asymptomatic bacteriuria: predisposing factors and correlation with preterm labor in low resource settings

Background Infection of urinary tract occurs frequently during pregnancy ranging from Asymptomatic Bacteriuria (ASB) to potentially life threatening acute pyelonephritis. The incidence varies from 5% to 20% and it is an important risk factor for preterm labor and perinatal morbidity and mortality. The present study was performed to correlate preterm labor and to define other risk factors associated with ASB like gravida status, socioeconomic status, and anaemia in pregnant women with ASB in low resource settings.

Methods A total of 1000 pregnant mothers in second and third trimester of pregnancy were screened for ASB by using two rapid reagent strip tests, namely nitrate and leukocyte esterase reagent strip tests. Out of those screened positive hundred consecutive pregnant women were taken as cases, after positive urine culture and out of those screened negative, two hundred patients were followed as controls after matching and pairing with cases. A detailed history was taken from each patient to determine all risk factors for ASB. The cases and controls were followed prospectively till delivery.

Results Mean gestational age at the time of labor in 100 cases of ASB was 35.6 ± 2.9 weeks and in 200 controls was 37.9 ± 0.6 weeks. The difference between mean gestational age at the time of labor in cases and controls was statistically significant (P value 0.000). The likelihood of preterm labor in the cases was 14.5 times more than the control and the difference was significant   (P <0.05).

Conclusions ASB leads to a higher rate of preterm labor and is more frequently seen in population with anemia, illiteracy, rural background and low socioeconomic status.