OBJECTIVES: To study the effect of sex on the clinical outcome of extremely preterm infants (EPIs)/extremely low birth weight infants (ELBWIs) by propensity score matching. METHODS: A retrospective analysis was performed for the medical data of 731 EPIs or ELBWIs who were admitted from January 1, 2011 to December 31, 2020. These infants were divided into two groups: male and female. A propensity score matching analysis was performed at a ratio of 1:1. The matching variables included gestational age, birth weight, percentage of withdrawal from active treatment, percentage of small-for-gestational-age infant, percentage of use of pulmonary surfactant, percentage of 1-minute Apgar score ≤3, percentage of mechanical ventilation, duration of mechanical ventilation, percentage of antenatal use of inadequate glucocorticoids, and percentage of hypertensive disorders in pregnancy. The two groups were compared in the incidence rate of main complications during hospitalization and the rate of survival at discharge. RESULTS: Before matching, compared with the female group, the male group had significantly higher incidence rates of neonatal respiratory distress syndrome, bronchopulmonary dysplasia (BPD), severe intraventricular hemorrhage, periventricular leukomalacia, necrotizing enterocolitis, and patent ductus arteriosus (P<0.05), while after matching, the male group only had a significantly higher incidence rate of BPD than the female group (P<0.05). There was no significant difference in the rate of survival at discharge between the two groups before and after matching (P>0.05). CONCLUSIONS Male EPIs/ELBWIs have a higher risk of BPD than female EPIs/ELBWIs, but male and female EPIs/ELBWIs tend to have similar outcomes.
Bronchopulmonary Dysplasia/etiology* ; Female ; Humans ; Infant ; Infant, Extremely Low Birth Weight ; Infant, Extremely Premature ; Infant, Newborn ; Male ; Pregnancy ; Propensity Score ; Retrospective Studies ; Sex Characteristics

OBJECTIVES: To investigate the risk factors for moderate/severe bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age of <32 weeks. METHODS: A retrospective analysis was performed on the medical data of preterm infants with a gestational age of <32 weeks and a length of hospital stay of ≥28 days who were admitted to the neonatal intensive care unit (NICU) of 17 institutions of Jiangsu Neonatal Perinatal Cooperation Network from January 1, 2019 to December 31, 2020 and were diagnosed with BPD. The preterm infants were grouped according to gestational age and severity of BPD. A multivariate logistic regression analysis was used to investigate the risk factors for moderate/severe BPD in various gestational age groups. RESULTS: During the two-year period, a total of 2 603 preterm infants with a gestational age of <32 weeks were admitted to the NICU of the 17 institutions, among whom 961 were diagnosed with BPD, and the incidence rates of BPD and moderate/severe BPD were 36.92% (961/2 603) and 8.64% (225/2 603), respectively. The incidence rate of moderate/severe BPD was 56.5% (26/46) in preterm infants with a gestational age of 24⁺⁰-25⁺⁶ weeks, 31.0% (66/213) in those with a gestational age of 26⁺⁰-27⁺⁶ weeks, 16.9% (75/445) in those with a gestational age of 28⁺⁰-29⁺⁶ weeks, and 22.6% (58/257) in those with a gestational age of 30⁺⁰-31⁺⁶ weeks. The multivariate logistic regression analysis showed that there were different risk factors for moderate/severe BPD in preterm infants with different gestational ages: patent ductus arteriosus requiring treatment as risk factors in preterm infants with a gestational age of 24⁺⁰-25⁺⁶ weeks; premature rupture of membranes ≥18 hours, positive pressure ventilation for resuscitation, clinical sepsis, and duration of mechanical ventilation ≥14 days as risk factors in preterm infants with a gestational age of 26⁺⁰-27⁺⁶ weeks; duration of mechanical ventilation ≥14 days, neonatal pneumonia, and patent ductus arteriosus requiring treatment as risk factors in preterm infants with a gestational age of 28⁺⁰-29⁺⁶ weeks; positive pressure ventilation for resuscitation, neonatal pneumonia, and anemia of prematurity as risk factors in preterm infants with a gestational age of 30⁺⁰-31⁺⁶ weeks (P<0.05). CONCLUSIONS The development of moderate/severe BPD is multifactorial in preterm infants with a gestational age of <32 weeks, and there are different risk factors in different gestational age groups. Targeted preventive measures for preterm infants of different gestational ages may be useful to reduce the severity of BPD.
Infant ; Pregnancy ; Female ; Infant, Newborn ; Humans ; Bronchopulmonary Dysplasia/etiology* ; Gestational Age ; Infant, Premature ; Ductus Arteriosus, Patent ; Retrospective Studies ; Risk Factors ; Pneumonia/complications*

OBJECTIVE: To systematically evaluate the association of early nutrition intake with the risk of bronchopulmonary dysplasia (BPD). METHODS: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Data, and Weipu Periodical Database were searched for the observational studies on the association between early nutrition intake and BPD. RevMan 5.3 software was used to perform a Meta analysis of eligible studies. RESULTS: Eight observational studies were included, with 548 infants with BPD and 522 infants without BPD. The Meta analysis showed that the BPD group had a significantly lower caloric intake than the non-BPD group within the first week after birth and in the first 2 weeks after birth ( CONCLUSIONS Early nutrition deficiency may be associated with the development of BPD, and more attention should be paid to enteral feeding of infants at a high risk of BPD to achieve total enteral feeding as soon as possible.
Bronchopulmonary Dysplasia/etiology* ; China ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Malnutrition ; Parenteral Nutrition

Bronchopulmonary dysplasia (BPD) has the main manifestations of pulmonary edema in the early stage and characteristic alveolar obstruction and microvascular dysplasia in the late stage, which may be caused by structural and functional destruction of the lung epithelial barrier. The Claudin family is the main component of tight junction and plays an important role in regulating the permeability of paracellular ions and solutes. Claudin-18 is the only known tight junction protein solely expressed in the lung. The lack of Claudin-18 can lead to barrier dysfunction and impaired alveolar development, and the knockout of Claudin-18 can cause characteristic histopathological changes of BPD. This article elaborates on the important role of Claudin-18 in the development and progression of BPD from the aspects of lung epithelial permeability, alveolar development, and progenitor cell homeostasis, so as to provide new ideas for the pathogenesis and clinical treatment of BPD.
Bronchopulmonary Dysplasia/etiology* ; Claudin-3 ; Claudins/genetics* ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Lung ; Tight Junctions

OBJECTIVES: To construct risk prediction models for bronchopulmonary dysplasia (BPD) in preterm infants on postnatal days 3, 7, and 14. METHODS: A retrospective analysis was performed on the medical data of 414 preterm infants, with a gestational age of <32 weeks and a birth weight (BW) of <1 500 g, who were admitted to the neonatal intensive care unit from July 2019 to April 2021. According to the diagnostic criteria for BPD revised in 2018, they were divided into a BPD group with 98 infants and a non-BPD group with 316 infants. The two groups were compared in terms of general status, laboratory examination results, treatment, and complications. The logistic regression model was used to identify the variables associated with BPD. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of models. RESULTS: The logistic regression analysis showed that BW, asphyxia, grade III-IV respiratory distress syndrome (RDS), acute chorioamnionitis, interstitial pneumonia, fraction of inspired oxygen (FiO CONCLUSIONS BW, asphyxia, grade III-IV RDS, acute chorioamnionitis, interstitial pneumonia, FiO
Bronchopulmonary Dysplasia/etiology* ; Female ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Pregnancy ; Respiration, Artificial ; Respiratory Distress Syndrome, Newborn ; Retrospective Studies

OBJECTIVETo study the expression of SUMO-modified CCAAT enhancer binding protein α (C/EBPα) in preterm rat model of bronchopulmonary dysplasisa (BPD) induced by hyperoxia exposure and its role.

METHODSEighteen preterm rats were randomly divided into an air group and a hyperoxia group (n=9 each). The model of BPD was prepared in preterm rats exposed to hyperoxia. The rats from the two groups were sacrificed on postnatal days 4, 7 and 14 respectively (3 rats at each time) and lung tissues were harvested. Periodic acid-Schiff (PAS) staining was used to observe the differentiation of rat lung tissues. Ki67 expression was detected by immunohistochemistry. Western blot was used to measure the protein expression of small ubiquitin-related modifier-1(SUMO1) and C/EBPα. A co-immunoprecipitation assay was performed to measure the protein expression of SUMO-modified C/EBPα.

RESULTSCompared with the air group, the hyperoxia group showed a decreased glycogen content in the lung tissue on postnatal day 4, and an increased content on postnatal days 7 and 14. Over the time of hyperoxia exposure, the hyperoxia group showed an increased expression of Ki67 in the lung tissue compared with the air group at all time points. Compared with the air group, the protein expression of C/EBPα increased on postnatal day 4 and decreased on postnatal days 7 and 14 in the hyperoxia group (P<0.05). The hyperoxia group had significantly upregulated expression of SUMO1 and SUMO-modified C/EBPα compared with the air group at all time points (P<0.05). In the hyperoxia group, the protein expression of SUMO-modified C/EBPα was positively correlated with the glycogen content (r=0.529, P<0.05) and the expression of Ki67 (r=0.671, P<0.05).

CONCLUSIONSHyperoxia may induce over-proliferation and differentiation disorders of alveolar epithelial cells in preterm rat model of BPD, possibly through an increased expression of SUMO-modified C/EBP&alpha.

Animals ; Animals, Newborn ; Bronchopulmonary Dysplasia ; etiology ; metabolism ; pathology ; CCAAT-Enhancer-Binding Protein-alpha ; metabolism ; Cell Proliferation ; Disease Models, Animal ; Hyperoxia ; complications ; pathology ; Ki-67 Antigen ; analysis ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Sprague-Dawley ; Sumoylation

OBJECTIVETo study the effect of pregnancy-induced hypertension syndrome (PIH) on complications in very low birth weight (VLBW) preterm infants.

METHODSThe VLBW preterm infants were enrolled as research subjects, and according to the presence or absence of PIH in their mothers, they were divided into PIH group and non- PIH group. The incidence of major complications and length of hospital stay were compared between the two groups.

RESULTSThere were no significant differences between the two groups in gestational age, birth weight, sex, incidence rate of maternal diabetes, and use of antepartum hormone. The PIH group had a significantly higher rate of birth of small-for-gestational-age infants than the non-PIH group. The PIH group had a significantly lower incidence rate of bronchopulmonary dysplasia (BPD) than the non-PIH group, while there were no significant differences between the two groups in the incidence rates of apnea of prematurity, necrotizing enterocolitis, retinopathy of prematurity, and intraventricular hemorrhage-periventricular leukomalacia, and the length of hospital stay. There was no significant difference in the incidence rate of neonatal respiratory distress syndrome between the two groups, but the PIH group had a significantly lower proportion of infants who used pulmonary surfactant than the non-PIH group.

CONCLUSIONSPIH can alleviate respiratory complications and reduce the use of pulmonary surfactant and the incidence rate of BPD in preterm infants.

Bronchopulmonary Dysplasia ; epidemiology ; etiology ; Female ; Humans ; Hypertension, Pregnancy-Induced ; Incidence ; Infant, Premature ; Infant, Very Low Birth Weight ; Pregnancy ; Pulmonary Surfactants ; therapeutic use ; Respiratory Distress Syndrome, Newborn ; epidemiology

With the development of treatment, the survival rate of premature infants has significantly increased, especially extremely premature infants and very low birth weight infants. This has led to an increase in incidence of bronchopulmonary dysplasia (BPD) year by year. BPD has been one of the most common respiratory system diseases in premature infants, especially the small premature infants. Arrested alveolar development is an important cause of BPD. Therefore, the mechanism of arrested alveolar development and the intervention measures for promoting alveolar development are the focuses of research on BPD. Selecting the appropriate animal model of BPD is the key to obtaining meaningful results in the basic research on BPD. Based on above, several common methods for establishing an animal model of BPD and the corresponding changes in pathophysiology are summarized and evaluated in order to provide a reference for selecting the appropriate animal model in studies on the pathogenesis, pathophysiology, and prevention and control strategies of BPD.
Animals ; Bronchopulmonary Dysplasia ; etiology ; Disease Models, Animal ; Humans ; Hyperoxia ; complications ; Respiration, Artificial ; adverse effects

OBJECTIVETo investigate the importance of breastfeeding in preterm infants with various gestational ages.

METHODSA total of 639 preterm infants with a gestational age of 28-36weeks were enrolled, and according to the feeding pattern, they were divided into exclusive breastfeeding group (n=237) and formula milk feeding group (fed with liquid milk for preterm infants; n=402). These two feeding patterns were compared in terms of their effects on weight gain, laboratory markers including albumin (Alb) and alkaline phosphatase (ALP), incidence rate of feeding intolerance, and incidence rates of complications including necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP).

RESULTSCompared with the formula milk feeding group, the breastfeeding group had a significantly faster increase in body weight, a significantly lower incidence rate of NEC, a significantly higher ALP level, and a significantly lower Alb level in the preterm infants with a gestational age of 28-30 weeks (P<0.05); there were no significant differences between the two groups in the incidence rates of anemia, ROP, bronchopulmonary dysplasia (BPD), and nosocomial infection and length of hospital stay (P>0.05). For the preterm infants with a gestational age of 31-33 weeks, the breastfeeding group had a significantly faster increase in body weight, a significantly lower incidence rate of feeding intolerance, a significantly shorter length of hospital stay, and a significantly higher ALP level (P<0.05); there were no significant differences between the two groups in the incidence rates of NEC, anemia, ROP, BPD, and nosocomial infection and the Alb level (P>0.05). For the preterm infants with a gestational age of 34-36 weeks, there were no significant differences in these indices between the two groups (P>0.05).

CONCLUSIONSBreastfeeding plays an important role in increasing body weight, reducing the incidence rates of feeding intolerance and NEC, and shortening the length of hospital stay in preterm infants with a gestational age of 28-33 weeks.

Breast Feeding ; Bronchopulmonary Dysplasia ; etiology ; Enterocolitis, Necrotizing ; etiology ; Humans ; Infant Formula ; Infant, Newborn ; Infant, Premature ; Intensive Care Units, Neonatal ; Retinopathy of Prematurity ; etiology

OBJECTIVETo assess the association between serum 25-hydroxyvitamin D [25(OH)D] levels at birth and bronchopulmonary dysplasia (BPD) in preterm infants.

METHODSThis study recruited preterm infants with gestational age of below 34 weeks who were born between January 2014 and December 2016. These preterm infants were classified into two groups: BPD and control. The association between serum 25(OH)D levels at birth and BPD was analyzed.

RESULTSSerum 25(OH)D levels in the BPD group was significantly lower than those in the control group [(37±17 nmol/L vs 47±20 nmol/L; P<0.05), and the rate of vitamin D deficiency was significantly higher than those in the control group (90.2% vs 74.0%; P<0.05). The level of serum 25(OH)D was negatively correlated with the incidence of BPD (r=-0.201, P=0.001).

CONCLUSIONSVitamin D deficiency at birth may be associated with BPD in preterm infants, but need to be further studied by multivariate analysis.

Bronchopulmonary Dysplasia ; blood ; etiology ; Female ; Humans ; Infant, Newborn ; Infant, Premature ; blood ; Male ; Vitamin D ; analogs & derivatives ; blood ; Vitamin D Deficiency ; complications