Prevalence and Accuracy of Screening Test of Asymptomatic Bacteriuria During Pregnancy in Siriraj Hospital

Abstract

Background. The early detection and treatment asymptomatic bacteriuria (ASB) during pregnancy prevents maternal and fetal complication. Thus the American College of OB-GYN recommends urine culture should be obtained at the first prenatal visit and the U.S. Preventive Services Task Force obtains urine culture during 12-16 weeks of gestation. The new antenatal care (ANC) model of Thai Ministry of Public Health uses screening at first ANC by urine dipstick. However, neither research nor routine ASB screen in Siriraj Hospital because there was low prevalence and all pregnancy been screened by the obstetricians. Methods. Prospective cohort study was performed at the ANC clinic, OB-GYN department, Siriraj Hospital. Pregnancies of first antenatal care visit during January to December 2015 were enrolled. Urine culture (UC), Urine dipstick for nitrite (UDN), and Urine dipstick for leukocyte esterase (UDL), were performed. Subjects' baseline characteristics until birth delivery were collected. Results. Total 702 subjects were enrolled; median age, 28 yrs (range 16-45) and body mass index, 24.1 (range 14.0-44.3). The ASB prevalence was 2.3% (16 from 702) without significant difference between first, second, and thirdtrimester, P = 0.185. The most common organism was E. coli. Factors related to ASB were heart disease, P < 0.001 and having sexual intercourse during pregnancy, P = 0.005. The sensitivity and specificity of UDN and UDL were 37.5% and 99.0% and 56.3% and 55.7%, respectively. Positive predictive value and negative predictive value of UDN and UDL were 46.2% and 2.9% and 98.5% and 98.2%, respectively. No abnormal maternal and fetal outcomes were reported. Conclusion. According to very low prevalence of ASB in Siriraj hospital, routine urine culture may be unnecessary for all antenatal pregnancy. However, heart disease and sexual intercourse during pregnancy should be considered for screening and treatment. However, further evaluation of outcome, i.e. UTI, maternal and fetal complication of non-screening for ASB should be studied.