Development and validation of a risk prediction model for respiratory tract Ureaplasma urealyticum infection in preterm infants

Background: Ureaplasma urealyticum (UU) infection in preterm infants lacks typical clinical manifestations. This study aims to analyze the risk factors for UU infection in preterm infants, construct and validate a nomogram prediction model, and provide evidence for early clinical risk assessment.

Methods: A total of 430 preterm infants admitted to the Department of Neonatology of Jinjiang Municipal Hospital from September 2022 to December 2024 were selected as the research subjects. Polymerase chain reaction (PCR)-fluorescent probe method was used to detect UU-DNA in respiratory secretions within 48 hours after admission. According to the test results, the preterm infants were divided into the UU-positive group (n=92) and the UU-negative group (n=338). Multivariable binary logistic regression analysis was performed to identify independent risk factors for UU infection. R software was used to construct a nomogram prediction model for respiratory UU infection in preterm infants, and the receiver operating characteristic (ROC) curve was used to evaluate the efficacy of the model.

Results: Multivariable logistic regression analysis showed that maternal vaginal delivery [odds ratio (OR) =0.07, 95% confidence interval (CI): 0.033–0.149], premature rupture of membranes (OR =6.04, 95% CI: 3.023–12.065), chorioamnionitis (OR =3.498, 95% CI: 1.545–7.921), UU infection of the genital tract (OR =13.949, 95% CI: 6.858–28.373), and white blood cell count in preterm infants (OR =1.11, 95% CI: 1.033–1.192) were independent risk factors for UU infection in preterm infants. The above risk factors were introduced into R software to construct a nomogram model. The area under the ROC curve was 0.931 (95% CI: 0.905–0.956), the sensitivity was 90.2%, and the specificity was 82.8%, which had good prediction efficiency.

Conclusions: The nomogram model based on the five independent risk factors of vaginal delivery, premature rupture of membranes, chorioamnionitis, UU infection of the genital tract, and white blood cell count of preterm infants has a high predictive ability. For preterm infants with high-risk factors, UU detection should be performed in time to achieve early diagnosis and intervention, reduce the incidence of serious complications, and improve the prognosis of children.