To investigate the risk factors of intrauterine infectious pneumonia and bronchopulmonary dysplasia (BPD) in premature infants.

From January 2013 to November 2018, a total of 600 premature infants with intrauterine infectious pneumonia were collected from Huizhou the Sixth People’s Hospital of Huizhou City as intrauterine infectious pneumonia group, while 600 premature infants without infective pneumonia were selected as simple premature group during the same period. The sex, intrauterine distress, premature rupture of membranes > 24 h, amniotic fluid contamination, prolonged second stage of labor, history of late maternal fever, cesarean section, gestational age, birth mass, and 1 min Apgar score were compared between the above two groups, respectively; and multivariate Logistic regression analysis was performed. Total of 60 premature infants with BPD admitted to our hospital from January 2016 to December 2018 were collected as BPD group, while 60 cases of premature infants without BPD were collected as non-BPD group. The sex, intrauterine distress, pulmonary hemorrhage, cytomegalovirus infection, invasive mechanical ventilation therapy, transfusion of red blood cells within two weeks of birth, intrauterine infection, gestational age, birth mass, and 1 min Apgar score were compared between the above two groups, respectively; and multivariate Logistic regression analysis was performed.

The rates of intrauterine distress [224 (37.33%) vs. 78 (13.00%)], premature rupture of membranes > 24 h [308 (51.33%) vs. 99 (16.50%)], fever history of late pregnancy [117 (19.50%) vs. 54 (9.00%)] and BPD [133 (22.17%) vs. 35 (5.83%)] of cases in intrauterine infectious pneumonia group were significantly higher than those of simple premature group, with significant differences (χ² = 94.320, 162.408, 27.068, 66.473; all P < 0.001); but 1 min Apgar score [(7.08 ± 1.32) vs. (8.65 ± 1.41)] was significantly lower than that of simple premature group, with significant difference (t = 19.911, P < 0.001). Multivariate Logistic regression analysis showed that intrauterine distress, premature rupture of membranes > 24 h, history of advanced maternal fever were all independent risk factors of intrauterine infectious pneumonia in preterm infants (OR = 3.824, 4.017, 3.492; P = 0.001, 0.008, 0.015). The rates of intrauterine distress [12 (20.00%) vs. 3 (5.00%)], pulmonary hemorrhage [10 (16.67%) vs. 0 (0.00%)], cytomegalovirus infection [5 (8.33%) vs. 0 (0.00%)], invasive mechanical ventilation [46 (76.67%) vs. 2 (3.33%)], transfusion of red blood cells [51 (85.00%) vs. 2 (3.33%)] within two weeks of birth, intrauterine infection [23 (38.33%) vs. 6 (10.00%)] of cases in BPD group were significantly higher than those of non-BPD group, with significant differences (χ² = 6.171, 10.909, 5.217, 67.222, 81.138, 13.141; P = 0.013, 0.001, 0.022, < 0.001, < 0.001, < 0.001); but gestational age [(32.14 ± 1.20) weeks vs. (34.35 ± 2.74) weeks], birth mass [1 352.39 ± 209.57) g vs. (2 285.56 ± 356.82) g] and 1 min Apgar score [(7.23 ± 1.36) vs. (8.68 ± 1.75)] were significantly lower than those of non-BPD groups, with significant differences (t = 5.723, 17.468, 5.068; all P < 0.001). Multivariate Logistic regression analysis showed that cytomegalovirus infection, invasive mechanical ventilation therapy, transfusion of red blood cells within two weeks of birth, gestational age and birth mass were all independent risk factors for preterm infants with BPD (OR = 44.357, 3.082, 3.290, 4.738, 3.409; P < 0.001, 0.003, 0.002, < 0.001, 0.009).

Endometrial distress, premature rupture of membranes > 24 h, history of fever may increase the risk of intrauterine infectious pneumonia in preterm infants, and cytomegalovirus infection, invasive mechanical ventilation therapy, transfusion of red blood cells within two weeks of birth, gestational age, and birth mass may affect BPD incidence.