Clinical features and outcomes at discharge of outborn very preterm infants of different ages after interhospital transfer / 中华围产医学杂志

Objective:To analyze the distribution of ages at the interhospital transfer of outborn very preterm infants in China and to compare their perinatal characteristics and outcomes at discharge and neonatal intensive care unit (NICU) treatment.Methods:A total of 3 405 outborn very premature infants with a gestational age of 24-31 +6 weeks who were transferred to the NICUs of the Chinese Neonatal Network (CHNN) in 2019 were included in this retrospective study. According to the age at transfer, they were divided into three groups: early transfer (≤1 d), delayed transfer (>1-7 d) and late transfer (>7 d) groups. Analysis of variance, t-test, Chi-square test (Bonferroni correction), Kruskal-Wallis test and Wilcoxon rank-sum test were used to compare the general clinical condition, treatment, and outcomes at discharge among the three groups. Results:The median gestational age was 29.7 weeks (28.3-31.0 weeks) and the average birth weight was (1 321.0 ± 316.5) g for these 3 405 infants. There were 2 031 patients (59.6%) in the early transfer group, 406 (11.9%) in the delayed transfer group and 968 (28.4%) in the late transfer group. Infants who received continuous positive airway pressure ventilation and tracheal intubation in the delivery room accounted for 8.4% (237/2 806) and 32.9% (924/2 805), respectively. A total of 62.7% (1 569/2 504) of the mothers received antenatal glucocorticoid therapy and the ratio in the early transfer group was 68.7% (1 121/1 631), which was higher than that in the delayed transfer group [56.1% (152/271), χ2=16.78, P<0.017] and the late transfer group [49.2% (296/602), χ2=72.56, P<0.017]. The total mortality rate of very premature infants was 12.7% (431/3 405), and the mortality rates in the early, delayed and late transfer groups were 12.4% (252/2 031), 16.3% (66/406) and 11.7% (113/968), respectively ( χ2=5.72, P=0.057). The incidences of severe intraventricular hemorrhage, late-onset sepsis, necrotizing enterocolitis, and bronchopulmonary dysplasia at the corrected gestational age of 36 weeks or discharge were all higher in the delayed and late transfer groups than in the early transfer group, respectively. The incidences of retinopathy of prematurity, retinopathy of prematurity requiring treatment and bronchopulmonary dysplasia at the corrected gestational age of 36 weeks or discharge in the late transfer group were significantly higher than that in the delayed transfer group (Bonferroni correction, all P<0.017). In the late transfer group, the median age of very premature infants at discharge was 66.0 d (51.0-86.0 d), and the corrected gestational age at discharge was 38.9 weeks (37.1-41.2 weeks), and both were greater than those in the early transfer [48.0 d (37.0-64.0 d), Z=260.83; 36.9 weeks (35.7-38.3 weeks), Z=294.32] and delayed transfer groups [52.0 d (41.0-64.0 d), Z=81.49; 37.4 weeks (36.1-38.7 weeks), Z=75.97] (all P<0.017). Conclusions:Many very premature infants need to be transferred to higher-level hospitals after birth. The later the very premature infants are transferred, the higher the incidence of complications will be. It is suggested that intrauterine or early postnatal transport may improve the prognosis of very premature infants.

Use of antenatal corticosteroids among infants with gestational age at 24 to 31 weeks in 57 neonatal intensive care units of China: a cross-sectional study / 中华医学杂志(英文版)

BACKGROUND@#Antenatal corticosteroids (ACS) can significantly improve the outcomes of preterm infants. This study aimed to describe the ACS use rates among preterm infants admitted to Chinese neonatal intensive care units (NICU) and to explore perinatal factors associated with ACS use, using the largest contemporary cohort of very preterm infants in China.@*METHODS@#This cross-sectional study enrolled all infants born at 24 +0 to 31 +6 weeks and admitted to 57 NICUs of the Chinese Neonatal Network from January 1st, 2019 to December 30th, 2019. The ACS administration was defined as at least one dose of dexamethasone and betamethasone given before delivery. Multiple logistic regressions were applied to determine the association between perinatal factors and ACS usage.@*RESULTS@#A total of 7828 infants were enrolled, among which 6103 (78.0%) infants received ACS. ACS use rates increased with increasing gestational age (GA), from 177/259 (68.3%) at 24 to 25 weeks' gestation to 3120/3960 (78.8%) at 30 to 31 weeks' gestation. Among infants exposed to ACS, 2999 of 6103 (49.1%) infants received a single complete course, and 33.4% (2039/6103) infants received a partial course. ACS use rates varied from 30.2% to 100% among different hospitals. Multivariate regression showed that increasing GA, born in hospital (inborn), increasing maternal age, maternal hypertension and premature rupture of membranes were associated with higher likelihood to receive ACS.@*CONCLUSIONS@#The use rate of ACS remained low for infants at 24 to 31 weeks' gestation admitted to Chinese NICUs, with fewer infants receiving a complete course. The use rates varied significantly among different hospitals. Efforts are urgently needed to propose improvement measures and thus improve the usage of ACS.

Bacteroides fragilis ATCC25285 relieves colitis by inducing Treg cells differentiation via the TGF-β/Smad3 signaling pathway / 中国药科大学学报

@#The changes in intestinal flora are usually associated with different gastrointestinal diseases, and intestinal flora homeostasis can enhance immune tolerance and regulate intestinal immune balance.Previous studies have found that the increase of the relative abundance of Bacteroides fragilis (B.fragilis) in Bacteroides intestinalis can significantly enhance the expression of intestinal regulatory T cells (Treg) and anti-inflammatory cytokines, thus alleviating intestinal inflammation.However, the mechanism of B.fragilis regulating intestinal immunity is still unclear.In this study, an acute colitis model was constructed by giving 3% DSS in drinking water solution to SPF-grade C57BL/6 mice for 7 days, and exogenous supplementation B.fragilis was given to mice by gastric gavage to study its regulatory effect on intestinal immunity and its mechanism of action.The results showed that B.fragilis could improve the intestinal flora disorder in mice with colitis and increase the content of short-chain fatty acids (SCFAs), the main metabolite of the intestinal flora.By extracting mouse tissue lymphocytes, naive CD4+ T cells, and liposome-modified siRNA knockdown mouse Smad3, it was further discovered by flow cytometry that B.fragilis induced the expression of intestinal Treg cells and related cytokines through the TGF-β/Smad3 signaling pathway, which enhanced intestinal regulatory immunity and alleviated colitis.It was also found that B.fragilis activated TGF-β by increasing the expression of reactive oxygen species (ROS), thus inducing Treg cell differentiation and playing an immunomodulatory role.