Asymptomatic pyuria in pregnant women during the first trimester is associated with an increased risk of adverse obstetrical outcomes

Objective Urinalysis is included in the prenatal examination in the first trimester in Taiwan, in contrast to Western countries. We aimed to investigate whether asymptomatic pyuria as detected by urinalysis was associated with adverse perinatal outcomes. Materials and Methods A total of 1187 singleton pregnant women who received prenatal care at Kaohsiung Chang Gung Memorial Hospital between January 2012 and December 2013 were included for retrospective analysis. We defined asymptomatic pyuria as the presence of 15 or more white blood cells/μL in midstream urine without symptoms. Adverse perinatal outcomes including preterm delivery, preterm premature rupture of membrane, low birth weight, and Apgar scores were analyzed. Univariate and multivariate logistic regression analyses were used to identify independent predictors. Results The prevalence of asymptomatic pyuria was 21.3% in our cohort. Univariate analysis showed that pyuria was the only factor associated with preterm delivery before 36 weeks of pregnancy, preterm premature rupture of membrane, and low birth weight. In multivariate analysis, both pyuria (odds ratio: 4.89, 95% confidence interval: 1.80–13.25, p = 0.002) and a maternal age of 35 years or older (odds ratio: 3.46, 95% confidence interval: 1.11–10.78, p = 0.033) were significant independent predictors for a low 5 minute Apgar score (<7). Conclusion The identification of asymptomatic pyuria via urinalysis in the first trimester may be a predictor for adverse perinatal outcomes.