Clinical Effects of Ureaplasma urealyticum Colonization in Maternal Vaginal Fluid at Second Trimester on Neonatal Outcomes of Premature Infant ≤35 Weeks' Gestational Age

ABSTRACT

PURPOSE: The purpose of this study was to evaluate the relationship between maternal genital Ureaplasma urealyticum colonization in the second trimester and the neonatal outcomes. METHODS: We studied 577 premature infants born at ≤35 weeks' gestational age (GA) at Hallym University, Kangnam Sacred Heart Hospital from January 2008 to December 2014. Maternal vaginal specimens were collected and polymerase chain reaction and/or culture tests were done in the second trimester of pregnancy. The subjects were divided into 2 groups: a Uu colonization-positive group (UU) and a Uu-negative (control) group. Subgroup analyses were performed in extremely premature (23–28 weeks' GA) and premature (29–35 weeks' GA) infants. Various clinical outcomes were compared. RESULTS: Of 577 preterm infants, 311 were delivered with maternal Uu infection (UU, 53.9%). Mean GA (30.0±3.6 weeks vs. 31.0±3.7 weeks, P=0.010) and birth weight (1,685.6±680.4 g vs. 1,932.7±733.1 g, P=0.003) were lower in the UU group than in controls. However, there were no significant differences in GA and birth weight in extremely premature group. Premature labor (P=0.002) and histological chorioamnionitis (P=0.032) was significantly more common in the UU group, especially in mothers who delivered in third trimester (29–35 weeks' GA). In particular, the incidence of moderate-to-severe BPD was statistically higher in UU extremely premature group (60.8% vs. 32.2%) (P=0.001). CONCLUSION: Maternal colonization with Uu was associated with an increase in premature delivery and lower birth weights. Moderate-to-severe BPD was more common in premature infants born at ≤28 weeks' GA with maternal Uu colonization.