Factors In Preterm Infants Research Articles

A Systematic Review of Isotopically Measured Iron Absorption in Infants and Children Under 2 Years

Background: Iron is an essential element for critical biological functions, with iron deficiency negatively affecting growth and brain development and iron excess associated with adverse effects. The goal of this review is to provide a comprehensive assessment of up-to-date evidence on iron absorption measured isotopically in children, preterm infants, and full-term infants, up to 24 months of age. Methods: Search databases included Pubmed, Cochrane, Web of Science, and Scopus from a date range of 1 January 1953 to 22 July 2024. The included articles were experimental studies with iron absorption outcomes measured by isotopic techniques. The risk of bias was assessed using the Cochrane Risk of Bias Tool. Results: A total of 1594 records were identified from databases, and 37 studies were included in the quality review with a total of 1531 participants. Article results were grouped by study commonality: absorption and red blood cell incorporation, type of milk feedings, additives to improve absorption, how and when to supplement with iron, and iron forms and complimentary foods. Conclusions: The results from this review support the current recommendations of oral iron supplementation. Iron from breast milk has high bioavailability, and unmodified cow’s milk reduces iron absorption. Supplemental iron is required at 4–6 months for healthy, full-term infants and sooner for preterm infants. Ascorbic acid increases iron absorption in full-term infants and children. Lactoferrin and prebiotics are promising candidates for enhancing iron absorption, but they require further investigation. Research evidence of iron absorption mechanisms and modulating factors in preterm infants is limited and should be a research priority.

Investigation of Prognosis and Related Factors of Premature Neonates

The birth of premature infants remains a challenge in many societies. This cross-sectional study investigates prenatal care and influential factors in preterm infants hospitalized in the Neonatal Intensive Care Unit (NICU) of Fatemieh Educational-Medical Center in Hamadan, Iran, from March 2018 to March 2019. We examined premature infants with a gestational age of less than 37 weeks who were admitted to the NICU. Data on demographic and maternal characteristics, length of hospital stay, maternal underlying diseases, probable causes of preterm birth, neonatal complications, treatment types, treatment-related complications, resuscitation needs, ventilation, and mortality rates were extracted from patient records. Among 388 preterm infants studied, 204 (52.6%) were female. The mean gestational age was 31.8±2.8 weeks, birth weight was 1647.4±625.6 grams, and average hospital stay was 10.2±9.3 days. The most common maternal underlying disease was pregnancy-induced hypertension or preeclampsia (22.2%), respiratory distress syndrome, jaundice, and low birth weight were the leading reasons for hospitalization (84%). Neonatal outcomes included 92 (23.7%) deaths, 25 (6.4%) intraventricular hemorrhages, 39 (10.1%) patent ductus arteriosus cases, 20 (5.2%) bronchopulmonary dysplasia cases, and 41 (10.6%) retinopathy of prematurity cases. Regression analysis revealed significant predictors of neonatal mortality, including male gender, maternal underlying diseases, need for cardiopulmonary resuscitation, low Apgar score at one-minute, lower birth weight, shorter gestational age, and NICU stay duration. This study underscores the high neonatal mortality rate among preterm infants. Implementing preventive measures, particularly addressing maternal underlying diseases and low birth weight, can significantly reduce neonatal mortality.

A prediction nomogram for moderate-to-severe bronchopulmonary dysplasia in preterm infants < 32 weeks of gestation: A multicenter retrospective study.

Moderate-to-severe bronchopulmonary dysplasia (msBPD) is a serious complication in preterm infants. We aimed to develop a dynamic nomogram for early prediction of msBPD using perinatal factors in preterm infants born at <32 weeks' gestation. This multicenter retrospective study conducted at three hospitals in China between January 2017 and December 2021 included data on preterm infants with gestational age (GA) < 32 weeks. All infants were randomly divided into training and validation cohorts (3:1 ratio). Variables were selected by Lasso regression. Multivariate logistic regression was used to build a dynamic nomogram to predict msBPD. The discrimination was verified by receiver operating characteristic curves. Hosmer-Lemeshow test and decision curve analysis (DCA) were used for evaluating calibration and clinical applicability. A total of 2,067 preterm infants. GA, Apgar 5-min score, small for gestational age (SGA), early onset sepsis, and duration of invasive ventilation were predictors for msBPD by Lasso regression. The area under the curve was 0.894 (95% CI 0.869-0.919) and 0.893 (95% CI 0.855-0.931) in training and validation cohorts. The Hosmer-Lemeshow test calculated P value of 0.059 showing a good fit of the nomogram. The DCA demonstrated significantly clinical benefit of the model in both cohorts. A dynamic nomogram predicting msBPD by perinatal days within postnatal day 7 is available at https://sdxxbxzz.shinyapps.io/BPDpredict/. We assessed the perinatal predictors of msBPD in preterm infants with GA < 32 weeks and built a dynamic nomogram for early risk prediction, providing clinicians a visual tool for early identification of msBPD.

Peculiarities of melatonin levels in preterm infants.

Melatonin plays an important role in organism functioning, child growth, and development. Of particular importance is melatonin for preterm infants. The aim of our research was to study the peculiarities of melatonin levels depending on various factors in preterm infants with gestational age (GA) of less than 34weeks. The study involved 104 preterm infants with GA less than 34weeks who were treated in the neonatal intensive care unit (NICU). The level of melatonin in urine samples was determined by an enzyme-linked immunosorbent assay. Melatonin concentration was significantly lower in extremely and very preterm infants compared to moderate preterm (3.57 [2.10; 5.06] ng/ml vs. 4.96 [3.20; 8.42] ng/ml, p = 0.007) and was positively correlated with GA (Spearman r = 0.32; p < 0.001). Positive correlations were revealed between melatonin levels and Apgar scores at the 1st(Spearman r = 0.31; p = 0.001) and 5thminutes after birth (Spearman r = 0.35; p < 0.001). Melatonin levels were lower in newborns with respiratory distress syndrome (p = 0.011). No significant correlations were found between melatonin concentration and birth weight (Spearman r = 0.15; p = 0.130). There were no associations of melatonin concentrations and mode of delivery (p = 0.914), the incidence of early-onset sepsis (p = 0.370) and intraventricular hemorrhages (p = 0.501), and mechanical ventilation (p = 0.090). The results of multiple regression showed that gestational age at birth was the most significant predictor of melatonin level in preterm infants (B = 0.507; p = 0.001). Gestational age and the Apgar score were associated with decreased melatonin levels in preterm infants. The level of melatonin in extremely and very preterm infants was lower compared to moderate preterm infants.

Identification of risk factors in pre-term infants with abnormal general movements.

This study aimed to investigate the relationship between prenatal, perinatal, and postnatal risk factors for neurodevelopmental impairment (NDI) with the outcomes of General Movement (GM) Assessment (GMA) in pre-term infants at 3-5 months of age. We sought to identify the risk factors associated with the predictors of psychomotor development in pre-term newborns, such as normal fidgety movements (FMs), absent FMs, or abnormal FMs, assessed during the fidgety period of motor development. The SYNAGIS program (prophylactic of Respiratory Syncytial Virus Infection) was used to identify risk factors for the development of neuromotor deficits in 164 pre-term infants who were at high risk of developing these deficits. Based on the GMA, all participants were divided into three groups of infants who presented: (1) normal FMs; (2) absent FMs; and (3) abnormal FMs. The results of the current study suggest that abnormal GMs not only indicate commonly known factors like birth asphyxia (BA), respiratory distress syndrome (RDS), periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH) grades 3-4, but also predict the development of motor impairments. In the present study, several specific risk factors including bronchopulmonary dysplasia (BPD), infertility treatments, maternal acute viral/bacterial infections during pregnancy, and elevated bilirubin levels were identified as attributes of an atypical fidgety movement pattern. Additional clinical data, such as risk factors for NDI associated with early predictors of psychomotor development in pre-term newborns, i.e., absent or abnormal FMs, may be helpful in predicting neurological outcomes in pre-term infants with developmental concerns in the 1st month of life.

Development of myopia in laser-treated ROP infants: prematurity or laser photocoagulation?

To investigate the relationship between the development of corrected 1-year-old refraction values and risk factors in preterm infants who underwent laser photocoagulation (LPC) therapy for retinopathy of prematurity (ROP). The ophthalmic examination findings of preterm neonates who had developed Type I ROP and received LPC therapy were evaluated retrospectively. The association between spherical equivalent (SE) values and clinical findings were analyzed by using multivariable linear regression analysis. The study included 157 eyes of 80 neonates with a mean birth week of 27.1 ± 2.2weeks (23 to 32weeks) and a mean birth weight of 995 ± 273g (565 to 1760g). The treatments were administered on an average of 36.8 ± 2.7 (32 to 45weeks) postmenstrual age. LPC treatment was applied bilaterally to 77 of the 80 neonates included in the study, and unilaterally to 3 of them. The mean ± standard deviation of the SE value was 0.31 ± 1.89 diopters (D) (-8.00 to 4.63 D) according to the results of the 1-year corrected age refraction examination. In univariate analysis, no significant association between GA, BW, and ROP zone and SE value, while the number of laser spots (ß = - 0.27 ± 0.00 D, p = 0.00) and stage 3 ROP (ß = - 0.29 ± 0.37 D, p = 0.00) were significantly associated with the SE value. In multivariable linear regression analysis, a significant association between number of laser spot, stage 3 ROP and SE value (ß = - 0.25 ± 0.00 D, p = 0.01 for number of laser spot, ß = - 0.28 ± 0.36 D, p = 0.00 for stage 3 ROP). In conclusion, this study supports that stage of ROP and the number of laser spots count applied in photocoagulation treatment for ROP is significantly correlated with degree of myopia (p < 0.05).

Incidence of Hyponatremia and Associated Factors in Preterm Infants in Saudi Arabia.

Objective: To investigate the incidence of hyponatremia in preterm infants. The secondary aim was to determine the risk factors of late-onset of hyponatremia (LOH) and their influence on neonatal outcomes.Study design: The present study is a retrospective cohort study of 71 preterm infants born before 32 weeks of gestation at King Abdulaziz University Hospital and admitted to the neonatal intensive care unit, level 3, from January to December 2019. Hyponatremia was defined as a sodium level ≤ 132 mEq/L. Retrieved maternal characteristics included age, parity, booking status, medical problems, antenatal steroids, and method of delivery. Retrieved infant characteristics included birth weight, gestational age, Apgar scores, total parenteral nutrition (TPN), breast milk or formula feeding, and body weight. as well as data on early onset of sepsis, chronic lung disease (CLD), patent ductus arteriosus, retinopathy of prematurity, severe intraventricular hemorrhage, and prescribed antibiotics and diuretics.Results: Out of 72 preterm infants, 27% were diagnosed with hyponatremia. Early-onset hyponatremia (EOH) affected 7% (n=5) of the infants while 22.5% (n=16) of preterm neonates developed LOH (two infants developed both EOH and LOH). None of the investigated maternal characteristics were significantly associated with hyponatremia. Some infant characteristics were significantly associated with LOH: lower birth weight, lower gestational age, exclusive breastfeeding, longer duration TPN, and use of diuretics and antibiotics. Infants with LOH had longer hospital stays (p < 0.001) and higher risks of extra-uterine growth retardation (p = 0.007), CLD (p < 0.001), and sepsis (p = 0.001).Conclusion: Twenty-seven percent of preterm infants in King Abdul Aziz University Hospital are born with or develop hyponatremia. Risk factors significantly associated with LOH included lower gestational age, lower birth weight, exclusive breastfeeding, long-term TPN, and prescribed diuretics and antibiotics. Possible outcomes of hyponatremia were long-term hospital stays, growth retardation, sepsis, and CLD.

Protein C system in preterm babies with chronic lung disease: Prospective study.

Chronic lung disease (CLD) is a major neonatal pulmonary disorder associated with inflammation. Recent studies have shown that protein C anticoagulant pathways, such as those for protein C (PC), protein S (PS), and thrombomodulin (TM), could be useful indices for reflecting pulmonary injury. However, the involvement of these factors in preterm infants with very low birthweight (VLBW) who have developed CLD remains to be investigated. Here, we investigated whether PC pathway-related factors could predict the development of CLD in preterm infants with VLBW. We collected plasma samples from 26 preterm infants with VLBW (13 each from those with and without CLD) at the time of birth and measured TM, PC, and PS levels in their plasmas. We analyzed prospectively the relationship between these factors in infants with and without CLD. There were significant differences in gestational age, birthweight, Apgar score (5 min), and duration of mechanical ventilation between the CLD and non-CLD groups. No significant differences in the PC and PS levels at birth were observed between the two groups, whereas the TM levels in the CLD group were significantly higher than those in the non-CLD group (P = 0.013). The TM levels correlated with gestational age and duration of mechanical ventilation. However, covariance analysis demonstrated that gestational age was significantly associated with TM levels, and consequently, development of CLD was not associated with TM level at birth. Thrombomodulin, PC, and PS levels at birth could not predict the development of CLD in preterm infants with VLBW.

Late hyponatremia: its risk factors in preterm infants and short-term outcome

Background. Prematurity is one of the major health problems and common causes of neonatal mortality. One of the complications of premature infants is hyponatremia. The effect of hyponatremia on the prognosis of preterm infants has not been well studied. This study aimed to evaluate infants with late hyponatremia, its risk factors, and prognosis. Methods. This descriptive analytical study reviewed preterm infants (&lt;34 weeks) admitted to Al-Zahra or Children’s Hospital in Tabriz for one year (2019). Neonates diagnosed with hyponatremia after the second week were identified and evaluated for risk factors and short-term outcome. Results. A total of 186 neonates were studied. The mean gestational age of the neonates was 30 weeks (first and third quarters = 29-32 weeks). 101 (54.3%) infants were male. The route of delivery was the cesarean section in 60.7% of cases. Late hyponatremia was present in 50 (26.8 %) infants. Gestational age and birth weight were significantly lower in infants with hyponatremia than in the control group. Multivariate analysis showed that low birth weight, the use of prenatal steroids, and inappropriate weight for gestational age status independently predict the incidence of late hyponatremia. There was a significant relationship between the presence of prolonged late hyponatremia (over 7 days) and bronchopulmonary dysplasia and osteopenia of prematurity. However, no significant association was found between the presence of prolonged late hyponatremia in preterm infants with the length of hospital stay and in-hospital mortality. Conclusion. Based on the findings of this study, low birth weight, prenatal steroid use, and lack of appropriate weight for gestational age were risk factors for late hyponatremia in preterm infants. Prolonged hyponatremia is associated with bronchopulmonary dysplasia and osteopenia of prematurity

Incidence, characteristics and risk factors for perioperative cardiac arrest and 30-day-mortality in preterm infants requiring non-cardiac surgery

Study objectiveTo determine 30-day-mortality, incidence and characteristics of perioperative cardiac arrest as well as the respective independent risk factors in preterm infants undergoing non-cardiac surgery. DesignRetrospective observational Follow-up-study. SettingBielefeld University Hospital, a German tertiary care hospital. PatientsPopulation of 229 preterm infants (age < 37th gestational week at the time of surgery) who underwent non-cardiac surgery between 01/2008–12/2018. MeasurementsPrimary endpoint was overall 30-day-mortality. Secondary endpoints were the incidence of perioperative cardiac arrest and identification of independent risk factors. We performed univariate and multivariate analyses and calculated odds ratios (OR) for risk factors associated with these endpoints. Main results30-day-mortality was 10.9% and perioperative mortality 0.9%. Univariate risk factors for 30-day-mortality were perioperative cardiac arrest (OR,12.5;95%CI,3.1 to 50.3), comorbidities of lungs (OR,3.7;95%CI,1.2 to 11.3) and gastrointestinal tract (OR,3.5;95%CI,1.3 to 9.6); sepsis (OR,3.6;95%CI,1.4 to 9.5); surgery between 22:01–7:00 (OR,7.3;95%CI,2.4 to 21.7); emergency (OR,4.5;95%CI,1.6 to 12.4); pre-existing catecholamine therapy (OR,5.0;95%CI,2.1 to 11.9). Multivariate logistic regression indicated that perioperative cardiac arrest (OR,13.9;95%CI,2.7 to 71.3), low body weight (weight < 1000 g: OR,26.0;95%CI,3.2 to 212; 1000-1499 g: OR,10.3; 95%CI,1.1 to 94.9 compared to weight > 2000 g), and time of surgery (OR,5.9;95%CI,1.6 to 21.3) for 22:01–7:00 compared to 7:01–15:00) were the major independent risk factors of mortality. Incidence of perioperative cardiac arrests was 3.9% (9 of 229;95%CI,1.8 to 7.3). Univariate risk factors were congenital anomalies of the airways (OR,4.7;95%CI,1.2 to 20.3), lungs (OR,4.7;95%CI,1.2 to 20.3) and heart (OR,8.0;95%CI,2 to 32.2), pre-existing catecholamine therapy (OR,59.5;95%CI,3.4 to 1039), specifically, continuous infusions of epinephrine (OR,432;95%CI,43.2 to 4318). Conclusions30-day-mortality and the incidence of perioperative cardiac arrest of preterms undergoing non-cardiac surgery were higher than previously reported. The identified independent risk factors may improve interdisciplinary perioperative risk assessment, optimal preoperative stabilization and scheduling of optimal surgical timing.

Longitudinal Trajectories of Regional Cerebral Blood Flow in Very Preterm Infants during Third Trimester Ex Utero Development Assessed with MRI.

Background The third trimester of gestation is a crucial phase of rapid brain development, but little has been reported on the trajectories of cerebral blood flow (CBF) in preterm infants in this period. Purpose To quantify regional CBF in very preterm infants longitudinally across the ex utero third trimester and to determine its relationship with clinical factors associated with brain injury and premature birth. Materials and Methods In this prospective study, very preterm infants were enrolled for three longitudinal MRI scans, and 22 healthy full-term infants were enrolled for one term MRI scan between November 2016 and February 2019. Global and regional CBF in the cortical gray matter, white matter, deep gray matter, and cerebellum were measured using arterial spin labeling with postlabeling delay of 2025 msec at 1.5 T and 3.0 T. Brain injury and clinical risk factors in preterm infants were investigated to determine associations with CBF. Generalized estimating equations were used to account for correlations between repeated measures in the same individual. Results A total of 75 preterm infants (mean postmenstrual age [PMA]: 29.5 weeks ± 2.3 [standard deviation], 34.9 weeks ± 0.8, and 39.3 weeks ± 2.0 for each scan; 43 male infants) and 22 full-term infants (mean PMA, 42.1 weeks ± 2.0; 13 male infants) were evaluated. In preterm infants, global CBF was 11.9 mL/100 g/min ± 0.2 (standard error). All regional CBF increased significantly with advancing PMA (P ≤ .02); the cerebellum demonstrated the most rapid CBF increase and the highest mean CBF. Lower CBF was associated with intraventricular hemorrhage in all regions (P ≤ .05) and with medically managed patent ductus arteriosus in the white matter and deep gray matter (P = .03). Mean CBF of preterm infants at term-equivalent age was significantly higher compared with full-term infants (P ≤ .02). Conclusion Regional cerebral blood flow increased significantly in preterm infants developing in an extrauterine environment across the third trimester and was associated with intraventricular hemorrhage and patent ductus arteriosus. © RSNA, 2021 Online supplemental material is available for this article.

Cytokines and Exhaled Nitric Oxide Are Risk Factors in Preterm Infants for Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD) is the most common complication of extremely preterm birth. This study was aimed at detecting cytokine and fractional exhaled nitric oxide (FeNO) levels to evaluate their mechanisms and predicted significance for BPD. Preterm infants born at gestational age ≤ 32 weeks were recruited, and clinical data were collected. We detected ten cytokines, including IFN-γ, IL-10, IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-6, IL-8, and TNF-α on Days 1–3, Days 7–14, and Days 21–28 after birth by using the Meso Scale Discovery (MSD) technology. The FeNO levels of infants were measured when they met the discharge criteria. A total of 46 preterm infants were enrolled, consisting of 14 infants in BPD group and 32 infants in the control group. The gestational age (27.5 ± 1.3 vs. 29.9 ± 1.3 weeks) and birth weight (1021 ± 261 g vs. 1489 ± 357 g) were lower in the BPD group. The following were high-risk factors for BPD, as determined by multivariate logistic regression analysis: gestational age < 30 weeks, birth weight < 1000 g, PDA, longer mechanical ventilation, and higher FeNO. The cytokines of IL-6 and IL-8 on Days 7–14 and IL-4, IL-6, IL-8, and TNF-α on Days 21–28 were also high-risk factors for BPD. IL-6 contributed to BPD disease severity. Conclusion. The preterm infants with PDA and prolonged mechanical ventilation tended to develop BPD. The IL-6 and IL-8 were significantly increased on Days 7–14 and were high-risk factors for BPD. Moreover, the IL-6 level was associated with BPD disease severity. We speculated that NO was related to BPD via Th2 cell-mediated inflammatory responses such as IL-4 and IL-6. Cytokines might predict the occurrence of BPD.

Retinopathy of prematurity: Incidence and perinatal risk factors in a tertiary hospital in Saudi Arabia

Purpose: This study aims to estimate the incidence of retinopathy of prematurity (ROP) and investigate its perinatal and neonatal risk factors in a tertiary hospital in Saudi Arabia. Methodology: This was a retrospective cohort study of premature infants admitted to a neonatal intensive care unit at a tertiary hospital in Jeddah, Saudi Arabia, from January 2016 to December 2017. Participants who met the screening criteria for ROP were included and followed up until spontaneous recovery or laser treatment. Results: A total of 119 infants screened, the incidence of ROP was 21.8% (26/119). A plus disease was diagnosed in 15.4% (4/26) of the ROP infants. For most, 80.7% (21/26) of the ROP regressed spontaneously, and 19.2% (5/26) required a laser intervention. The mean gestational age (GA) of infants diagnosed with ROP was 25.62 ± 1.58 weeks and the median birth weight (BW) 750 (interquartile range: 280) g. Lower GA, lower BW, prolonged oxygen therapy, and mechanical ventilation (MV) were significantly related to ROP disease and severity. Requiring resuscitation at birth, a lower Apgar score at 1-min, poor weight gain proportion at 6 weeks, and requiring a blood transfusion were significantly associated with ROP disease. Conclusion: Compared to other local studies, the incidence of ROP was lower in our population. Lower GA, low BW, prolonged oxygen therapy and MV, and poor weight gain at 6 weeks are well-documented risk factors. We recommend close monitoring of weight gain and oxygen therapy and modifying risk factors in preterm infants to lower the incidence and the severity of ROP.

Mortality Risk Factors in Preterm Infants Treated with High-Frequency Jet Ventilation.

High-frequency jet ventilation (HFJV) has been used in conjunction with conventional ventilation for premature infants with respiratory failure. We sought to identify parameters that were associated with mortality in subjects who underwent HFJV. Subjects were enrolled if birthweight was ≤ 2,000 g and they were ≤ 34 weeks gestational age. Subjects were excluded if they received HFJV at the time of admission because we aimed to study subjects who failed conventional ventilation. Subject demographics, ventilator parameters, and laboratory data were extracted and analyzed. The Mann-Whitney U-test was used to assess differences in continuous variables, and the chi-square and Fisher exact tests were used for categorical variables between the groups. To assess variables that were predictive of mortality, we used both univariate and multivariate logistic regression analysis. Independent predictors of mortality were identified and used to create a multivariate risk score. Receiver operating characteristic curves were constructed to evaluate the predictive accuracy of the multivariate risk score. A total of 53 premature subjects (n = 37 male) were studied, of whom 39 (74%) survived to discharge or transfer back to referring hospital. In the univariate model, female sex, older gestational age, higher birthweight, HFJV peak inspiratory pressure at 1 h, and oxygen saturation index at 4 h were associated with mortality. In the final multivariate logistic regression model, female sex (odds ratio 4.1, 95% CI 1.2-19.8, P = .044), closed ductus arteriosus (odds ratio 7.7, 95% CI 1.3-39.5, P = .016), and oxygen saturation index > 5.5 (odds ratio 6.0, 95% CI 1.5-28.3, P = .02) were independent predictors of mortality. We identified that oxygen saturation index > 5.5 after 4 h of HFJV, female sex, and closed ductus arteriosus were independent predictors of mortality.

Development and validation of a nomogram for predicting late-onset sepsis in preterm infants on the basis of thyroid function and other risk factors: Mixed retrospective and prospective cohort study

Preterm birth and infection are common causes of neonatal death. In this study, we aimed to develop a nomogram for assessing the individual prior probability of late-onset sepsis on the basis of risk factors in preterm infants. This study is a mixed retrospective and prospective cohort study conducted in three centers. Data from January 2014 to December 2017 was used for the development cohort, and data from January 2018 to December 2018 was used for the validation cohort. In the development cohort, we identified the predicting variables of late-onset sepsis in preterm infants, from which a nomogram was obtained. Then we built nomograms, for with and without thyroid function, to predict late-onset sepsis. The nomogram was validated in the validation cohort concerning discrimination and calibration. A total of 1256 and 452 preterm infants were included in the development and validation cohort, respectively. We found thyroid hypofunction in preterm infants could increase the incidence of late-onset infection. The prediction model incorporated thyroid function, birth weight, use of endotracheal intubation, and duration of umbilical venous catheters was validated and developed as a nomogram for predicting late-onset sepsis in preterm infants. Nomogram in this study may contribute to clinical assessment and treatment decisions.

Cohort study of respiratory hospital admissions, air quality and sociodemographic factors in preterm infants born in California.

Preterm infants suffer from respiratory morbidity especially during the first year of life. To investigate the association of air quality and sociodemographic indicators on hospital admission rates for respiratory causes. This is a retrospective cohort study. We identified all live-born preterm infants in California from 2007 to 2012 in a population-based administrative data set and linked them to a data set measuring several air quality and sociodemographic indicators at the census tract level. All sociodemographic and air quality predictors were divided into quartiles (first quartile most favourable to the fourth quartile least favourable). Mixed effect logistic models to account for clustering at the census tract level were used to investigate associations between chronic air quality and sociodemographic indicators respiratory hospital admission during the first year of life. Of 205178 preterm infants, 5.9% (n=12033) were admitted to the hospital for respiratory causes during the first year. In the univariate analysis, comparing the first to the fourth quartile of chronic ozone (risk ratio [RR] 1.29, 95% confidence interval [CI] 1.21, 1.37), diesel (RR 1.10, 95% CI 1.02, 1.17) and particulate matter 2.5 (RR 1.07, 95% CI 1.01, 1.14) exposure were associated with hospital admission during the first year. Following adjustment for confounders, the risk ratios for hospital admission during the first year were 1.53 (95% CI 1.37, 1.72) in relation to educational attainment (per cent of the population over age 25 with less than a high school education) and 1.23 (95% CI 1.09, 1.38) for poverty (per cent of the population living below two times the federal poverty level). Among preterm infants, respiratory hospital admissions in the first year in California are associated with socioeconomic characteristics of the neighbourhood an individual is living in.

Risk Factors of Patent Ductus Arteriosus in Preterm

Patent Ductus Arteriosus (PDA) is one of acyanotic congenital heart diseases that often occurs in preterm infants and closely related to an increased risk of complications for sufferers. Identification of PDA risk factors in preterm infants is very important, so that the diagnosis and management can be done earlier. In this study we aimed to determine risk factors of PDA in preterm infants. This case-control study was conducted between July 2017 and April 2018, analysed 43 preterm infants with PDA as the case group and 43 preterm infants without PDA as the control group. The basic information related to characteristics, risk of infection and perinatal history in both groups were collected. Bivariate and multivariate analysis with logistic regression were performed to identify risk factors for PDA. We found several factors were identified significantly (P<0.05) as risk factors for PDA including premature rupture of membranes >12 hours (OR 7.25; 95% CI: 2.08 - 25.09) and thrombocytopenia in the first 24 hours (OR 15.11; 95% CI: 3.73 - 61.13). This study concluded premature rupture of membranes >12 hours and thrombocytopenia in the first 24 hours were proven to increase the risk of PDA in preterm infants.

Effect of early essential newborn care on omphalitis in vaginally born preterm infants

Objective To explore the influence of early essential newborn care(EENC) on the development of omphalitis in preterm infants following normal delivery. Methods A total of 184 preterm infants, admitted to General Hospital of Ningxia Medical University from January 2017 to December 2017, were retrospectively collected as EENC group. During the same period, 161 preterm infants who were born in Yinchuan Maternal and Child Health Hospital were included in the control group. Preterm infants in EENC group were managed based on the clinical practice guideline of Early Essential Newborn Care, while those in the control group underwent routine care after birth. The incidence of omphalitis between the two groups were compared using independent-samples t test and Chi-square test. Influencing factors of omphalitis were analyzed using univariate analysis and multivariate logistic regression analysis. Results The incidence of mild omphalitis was lower [5.4% (10/184) vs 11.8% (19/161), χ2=4.520, P<0.05], and the separation and drying up time of cord stump were both earlier in the EENC group than those in the control group [(5.5±1.5) vs (8.2±1.2) d, t=4.169; (2.6±1.4) vs (3.2±1.4) d, t=4.513; both P<0.05]. Logistic regression analysis showed that gestational age≤34 weeks (OR=1.885, 95%CI: 1.109-6.757, P=0.032), early umbilical cord clamping (OR=3.615, 95%CI: 1.372-9.381, P=0.001) and bandaging of the umbilical stump (OR=1.921, 95%CI: 1.257-11.893, P=0.035) were independent risk factors of omphalitis in preterm infants. Conclusions Umbilical cord treatment based on EENC could reduce the incidence of omphalitis by avoiding its risk factors in preterm infants following normal delivery. Key words: Infant, premature; Umbilicus; Inflammation; Umbilical cord; Constriction; Neonatal nursing

Fixel-based analysis of the preterm brain: Disentangling bundle-specific white matter microstructural and macrostructural changes in relation to clinical risk factors.

Diffusion MRI (dMRI) studies using the tensor model have identified abnormal white matter development associated with perinatal risk factors in preterm infants studied at term equivalent age (TEA). However, this model is an oversimplification of the underlying neuroanatomy. Fixel-based analysis (FBA) is a novel quantitative framework, which identifies microstructural and macrostructural changes in individual fibre populations within voxels containing crossing fibres. The aim of this study was to apply FBA to investigate the relationship between fixel-based measures of apparent fibre density (FD), fibre bundle cross-section (FC), and fibre density and cross-section (FDC) and perinatal risk factors in preterm infants at TEA. We studied 50 infants (28 male) born at 24.0–32.9 (median 30.4) weeks gestational age (GA) and imaged at 38.6–47.1 (median 42.1) weeks postmenstrual age (PMA). dMRI data were acquired in non-collinear directions with b-value 2500 s/mm2 on a 3 Tesla system sited on the neonatal intensive care unit. FBA was performed to assess the relationship between FD, FC, FDC and PMA at scan, GA at birth, days on mechanical ventilation, days on total parenteral nutrition (TPN), birthweight z-score, and sex. FBA reveals fibre population-specific alterations in FD, FC and FDC associated with clinical risk factors. FD was positively correlated with GA at birth and was negatively correlated with number of days requiring ventilation. FC was positively correlated with GA at birth, birthweight z-scores and was higher in males. FC was negatively correlated with number of days on ventilation and days on TPN. FDC was positively correlated with GA at birth and birthweight z-scores, negatively correlated with days on ventilation and days on TPN and higher in males. We demonstrate that these relationships are fibre-specific even within regions of crossing fibres. These results show that aberrant white matter development involves both microstructural changes and macrostructural alterations.

Vitamin A level and related clinical factors in preterm infants

Objective To investigate the association between serum vitamin A levels and clinical factors in preterm infants. Methods A retrospective study was conducted on neonates admitted to Peking University Third Hospital from May 2013 to May 2014. Totally, 89 preterm neonates were recruited (preterm group). Fifty term babies with hyperbilirubinemia were selected as hyperbilirubinemia group and 50 healthy term babies were chosen as control group. High-performance liquid chromatography (HPLC) was used to examine the serum vitamin A concentrations for preterm babies at the age of 2, 7, 14 and 28 days, while those for babies in hyperbilirubinemia group was measured on one week old. Umbilical cord blood serum vitamin A concentrations were determined in control group. t-test, univariate analysis of variance or multiple linear regression was used for statistical analysis. Results (1) In the preterm group, the mean serum vitamin A levels at the age of 2, 7, 14 and 28 days were (0.136±0.060), (0.141±0.047), (0.122±0.053) and (0.134±0.073) mg/L, respectively, while (0.168±0.109) and (0.159±0.049) mg/L in hyperbilirubinemia and the control group. The proportions of vitamin A deficiency (lower than 0.20 mg/L) in preterm babies were 91.2% (62/68), 92.1% (58/63), 91.3% (42/46) and 84% (21/25) at the age of 2, 7, 14 and 28 days respectively. There was no significant difference in serum vitamin A levels between the age of 2 days and the rest in preterms (P>0.05). However, the vitamin A levels in preterm babies at the age of 2 and 7 days were lower than that of control and hyperbilirubinemia group, respectively (t=-2.068 and -1.790, both P 0.05). (3) Multiple factor analysis showed that respiratory distress syndrome, neonatal pneumonia, small for gestational age and maternal hypertensive diserders of pregnancy were associated with serum vitamin A level in early life of newborns (all P<0.05). Conclusion Preterm infants might require sufficient vitamin A supplementation due to low vitamin A level in their first month of life. Small for gestational age, maternal hypertensive disorders of pregnancy, respiratory distress syndrome and neonatal pneumonia are associated with serum vitamin A level in preterm infants. Key words: Vitamin A; Infant, premature