Abstract: Objective Explore the relevant influencing factors of reproductive tract infections in late pregnancy women, and the relationship between reproductive tract infections and premature birth. Method 123 late pregnancy women who were treated at the Department of Obstetrics, Nanhai District People's Hospital in Foshan City from February 2018 to January 2020 were selected. They were divided into an infection group (n=49) and a control group (n=74) based on whether they had reproductive tract infections. The clinical data of the two groups of patients were compared, and Logistic regression analysis was used to analyze the independent risk factors of reproductive tract infections in late pregnancy women. 123 pregnant women were divided into preterm delivery group (n=35) and non preterm delivery group (n=88) based on whether they were born prematurely. The general information of the two groups of pregnant women was compared, and Logistic regression analysis was used to analyze the independent risk factors for preterm delivery in late pregnancy pregnant women. Build a prediction model based on independent factors and validate the model. Result Diabetes in pregnancy, low education level, poor health habits, abortion history, delivery history, infection history were independent risk factors of reproductive tract infection in late pregnancy (P<0.05). By comparing the conditions of preterm infants of different gestational ages at birth and after birth, we can see that the smaller the gestational age and the lower the birth weight, the higher the incidence rate and death rate of asphyxia, hyaline membrane disease, and intraventricular hemorrhage above Ul degree (P<0.05). Pregnancy diabetes, abortion history and reproductive tract infection were independent risk factors for preterm delivery in late pregnancy (P<0.05). Construct a prediction model for premature delivery in late pregnancy. The C-index calculation result of the prediction model is 0.863 (95% CI: 0.825-0.884), and the ROC curve AUC is 0.868 (95% CI: 0.822-0.963), which has good discrimination and accuracy. Conclusion Diabetes during pregnancy, low education level, poor health habits, abortion history, delivery history, infection history are the risk factors of reproductive tract infection in late pregnancy. Enhance maternal safety awareness, timely cleaning of the reproductive tract and regular relevant examinations, reduce unnecessary abortion and cesarean section, effectively reduce the risk of reproductive tract infection and the rate of preterm birth.

Key words: Late pregnancy, Pregnant women, Reproductive tract infections, Premature delivery