Background: The impact of and countermeasures for Ureaplasma spp. in neonates remain controversial. The aim of this study was to evaluate the associated perinatal factors that can predict the likelihood of respiratory tract Ureaplasma spp. colonization and analyze the subsequent clinical course of affected infants, thereby providing the rationale for their diagnosis, treatment, and future study. Methods: This was a retrospective observational study of infants born at a gestational age (GA) of less than 32 weeks. Results: The prevalence of respiratory tract Ureaplasma spp. colonization was 25.8% (75/291), and it increased with a decrease in GA and birth weight (BW). Maternal vaginal Ureaplasma spp. colonization increased the risk of neonatal Ureaplasma spp. colonization, with an OR of 7.8 (95% CI: 3.1, 20.0). Infants with Ureaplasma spp. colonization had a higher white blood cell (WBC) count, normal C-reactive protein (CRP) level, and higher failure rate of weaning from mechanical ventilation (30.7% vs. 17.1%, p = 0.014); they also suffered more from interstitial pneumonia (20.0% vs. 5.6%, p < 0.001) and bronchopulmonary dysplasia (36.0% vs. 13.4%, p < 0.001). Infants receiving anti-Ureaplasma spp. treatment had a lower GA, lower BW, and more severe respiratory syndromes. However, the difference in respiratory manifestation became insignificant after adjusting for GA. Conclusions: GA and maternal vaginal Ureaplasma spp. colonization could be used to predict neonatal respiratory tract Ureaplasma spp. colonization. An elevated WBC count combined with normal CRP is a good marker of Ureaplasma spp. colonization/infection. It is conventional practice to start anti-Ureaplasma spp. treatment when infants present with a deteriorated respiratory condition. This practice warrants further investigation considering GA as a predominant intermediate variable.
