Early Vitamin A Supplementation for Prevention of Short-Term Morbidity and Mortality in Very-Low-Birth-Weight Infants: A Systematic Review and Meta-Analysis

BACKGROUND

Vitamin A plays an important role in the development and maintenance of the normal function of organs and systems. Premature infants have low levels of vitamin A, which may be associated with an increased risk of developing disease. This study aimed to evaluate the effects of vitamin A supplementation on short-term morbidity and mortality in very-low-birth-weight (VLBW) infants.

METHODS

We used PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and Web of Science to conduct a literature search of studies published before January 1, 2022, to be included in our meta-analysis. The analysis included randomized controlled trials that compared the effects of vitamin A supplementation on VLBW infants (birth weight <1,500 g) and controls given a placebo or no treatment. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE) guidelines.

RESULTS

Twelve randomized controlled trials were included in the meta-analysis, and 2,111 infants were pooled and analyzed. The overall risk of bias was not serious in the included studies. Vitamin A supplementation for reducing the incidence of bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age seems to be limited [risk ratio (RR):0.85; 95% confidence intervals (CI): 0.70-1.04; 8 studies, 1,595 infants, very-low-certainty evidence], which is different from the previous systematic review. Length of hospital stay (mean difference: -12.67, 95% CI: -23.55 to -1.79; 6 studies, 739 infants, low-certainty evidence), and the incidence of vitamin A deficiency at 28 days postnatal age (RR: 0.08; 95% CI: 0.02-0.38; 3 studies, 358 infants, low-certainty evidence) were reduced in the vitamin A group. Besides, vitamin A supplementation seems to reduce the incidence of periventricular leukomalacia (RR: 0.68; 95% CI: 0.47-0.97; 4 studies, 1,224 infants, low-certainty evidence) and retinopathy of prematurity of any grade (RR: 0.61; 95% CI: 0.48-0.76; 4 studies, 463 infants, moderate-certainty evidence).

CONCLUSIONS

There is no sufficient evidence regarding vitamin A supplementation preventing BPD in VLBW infants. Vitamin A supplementation can reduce the incidence of vitamin A deficiency and retinopathy of prematurity of any grade, and may exert an effect of preventing periventricular leukomalacia.

SYSTEMATIC REVIEW REGISTRATION

http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42020211070.

Gut Dysbiosis, Bacterial Colonization and Translocation, and Neonatal Sepsis in Very-Low-Birth-Weight Preterm Infants

Gut dysbiosis may precede neonatal sepsis, but the association is still not well-understood. The goal of this study is to investigate the association between gut microbiota and neonatal sepsis, and to seek the evidence of colonization of pathogenic bacteria in the gut before evolving into an invasive infection. A prospective cohort study examined fecal microbiota composition in preterm infants with and without sepsis. Thirty-two very-low-birth-weight (VLBW) preterm infants and 10 healthy term infants as controls were enrolled. The fecal samples collected from the participants at the first, fourth, and seventh weeks of life underwent 16S rRNA amplicon sequencing for measurement of the diversity and composition of the microbiota. The bacterial isolates causing neonatal sepsis were genome sequenced. PCR was performed to confirm the translocation of the bacteria from the gut to the blood. The results showed that VLBW preterm infants with sepsis had lower microbial diversity in the gut at birth compared to preterm infants without sepsis and term infants. The composition of gut microbiome in preterm infants was similar to healthy terms at birth but evolved toward dysbiosis with increasing Proteobacteria and decreasing Firmicutes weeks later. The strain-specific PCR confirmed the presence of causative pathogens in the gut in 4 (40%) out of 10 VLBW preterms with sepsis before or at onset of sepsis, and persistence of the colonization for weeks after antibiotic treatment. The same bacterial strain could horizontally spread to cause infection in other infants. Prolonged antibiotic exposure significantly reduced beneficial Bifidobacterium and Lactobacillus in the gut. In conclusion, preterm infants with gut dysbiosis are at risk for neonatal sepsis, and the causative pathogens may be from the gut and persist to spread horizontally. The association of increased Proteobacteria abundance and decrease in microbiome diversity suggests the need for interventions targeting the gut microbiome to prevent dysbiosis and sepsis in VLBW preterm infants.

Predictive Validity of the Bayley-III Cognitive Scores at 6 Months for Cognitive Outcomes at 24 Months in Very-Low-Birth-Weight Infants

Purpose: To assess the predictive validity of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) cognitive scores at 6 months of corrected age (CA) for cognitive outcomes at 24 months of CA in very-low-birth-weight (VLBW) infants and investigate the predictors of change in cognitive outcomes. Methods: We retrospectively evaluated VLBW children enrolled in the Taiwan Premature Infant Follow-up Network between 2010 and 2015 and completed the Bayley-III at CA of 6 and 24 months. The predictive validity of the cognitive performance at 6-month CA for the cognitive outcomes at 24-month CA was analyzed. The positive and negative predictive factors were also evaluated using logistic regression. Cut-off scores of <70 and <85 were used to identify lower functioning groups based on the Bayley-III definition. Results: A total of 2,972 VLBW children, born with a mean weight of 1116.4 ± 257.5 g and mean gestational age of 29.0 ± 2.8 weeks, were evaluated. A cognitive score of <70 at 6-month CA had a positive predictive value (PPV) of 27.4% (95% confidence interval [CI]: 19.2-35.7%) for a cognitive score of <70 at 24-month CA, while the negative predictive value (NPV) was 97.3% (95% CI: 96.7-97.9%). A cut-off score of 85 had a PPV of 33.6% (95% CI: 28.1-39.0%) and an NPV of 87.7% (95% CI: 86.4-88.9%). Abnormal muscle tone at 6 months was a risk factor for cognitive function decline at 24 months for both Bayley-III cognitive cut-off scores: scores of 70 (adjusted odds ratio [AOR]: 2.8; 95% CI: 1.5-5.5) and 85 (AOR: 2.6; 95% CI: 1.6-4.1). Lower maternal socioeconomic status was associated with a worsening of the cognitive function in infants at 24 months who scored ≥85 at 6 months (AOR: 1.6; 95% CI: 1.2-2.0). Conclusion: Subnormal Bayley-III cognitive scores at 6-month CA were not predictive of subnormal cognitive function at 24-month CA. In children with normal cognition during early infancy, abnormal muscle tone and lower maternal socioeconomic status may influence the cognitive developing process; this highlighted the importance of early identification of high risk infants and complete preterm infant-associated public health policies to promote an improved neurodevelopmental outcome.

Short- and Long-Term Outcomes of Extremely Preterm Infants in Japan According to Outborn/Inborn Birth Status

OBJECTIVES

Outborn (born outside tertiary centers) infants, especially extremely preterm infants, are at an increased risk of mortality and morbidity in comparison to inborn (born in tertiary centers) infants. Extremely preterm infants require not only skilled neonatal healthcare providers but also highly specialized equipment and environment surroundings. Maternal transport at an appropriate timing must be done to avoid the delivery of extremely preterm infants in a facility without the necessary capabilities. Cases of unexpected deliveries at birth centers or level I maternity hospitals need to be attended emergently. We compared the differences in short- and long-term outcomes between outborn and inborn infants to improve our regional perinatal system.

DESIGN

Retrospective cohort study.

SETTING

Neonatal Research Network of Japan database.

PATIENTS

Extremely preterm infants (gestational age between 22 + 0 and 27 + 6 wk) in the Neonatal Research Network of Japan database between 2003 and 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 12,164 extremely preterm infants, who were divided into outborn (n = 785, 6.5%) and inborn (n = 11,379, 93.5%) groups, were analyzed. Significant differences were observed in demographic and clinical factors between the two groups. Outborn infants had higher short-term odds of severe intraventricular hemorrhage (adjusted odds ratio, 1.49; 95% CI, 1.11-2.00; p < 0.01), necrotizing enterocolitis (adjusted odds ratio, 1.49; 95% CI, 1.11-2.00; p < 0.01), and focal intestinal perforation (adjusted odds ratio, 1.58; 95% CI, 1.09-2.30; p = 0.02). There were no significant differences in long-term outcomes between the two groups, except in the rate of cognitive impairment (adjusted odds ratio, 1.49; 95% CI, 1.01-2.20; p = 0.04).

CONCLUSIONS

The frequency of severe intraventricular hemorrhage, necrotizing enterocolitis or focal intestinal perforation, and cognitive impairment was significantly higher in outborn infants. Thus, outborn/inborn birth status may play a role in short- and long-term outcomes of extremely preterm infants. However, more data and evaluation of improvement in the current perinatal environment are needed.

Morbidity in ≤1500-Gram Births in Spain, 1993-2011: Study of a Sample of 1200 Cases

Background and Objective. Preterm birth has a major impact on growth, and very preterm birth is associated with disabilities in numerous developmental domains. This article describes and quantifies morbidities in a sample of 1200 ≤1500-g births in Spain between 1993 and 2011 based on parent information, and it highlights several variables that influence these morbidities. Methods. Multiple method surveys using computer-assisted telephones interviewing and computer-assisted web interviewing methods. Sample design was intentional. Most subjects were contacted via their referral hospitals. Data collection was done from April 2013 to June 2014. Prior to the survey, extensive qualitative fieldwork was conducted, including nonparticipant observation in neonatal units and the design and analysis of discussion groups and interviews with professionals and families, including preterm adolescents. Results. A total of 44.2% of the sample were experiencing morbidity (mean: 1.788 morbidities per child). The most prevalent types were learning difficulties (34.4%) and attention deficit/hyperactivity disorder (31.5%). The most influential variables were male gender, age, lower birthweight, private hospital admission for birth, scarcity of health resources in the family's residential area, non-Spanish maternal birthplace, and emotional distress in the primary carer. Conclusions. Overall, the total percentage of very low birth weight children with morbidities has decreased moderately between 1993 and 2011, thanks to major socio-sanitary improvements during this period. Biological and medical variables, rather than family factors, explain more accurately the presence of morbidities in children with birth weight ≤1500 g.

Neurodevelopmental outcome in very low birthweight infants with pathological umbilical artery flow

OBJECTIVE

To assess neurodevelopmental outcome during toddlerhood in very low birthweight (VLBW) infants with absent or reverse end-diastolic flow (AREDF) in the umbilical artery (UA) during pregnancy.

DESIGN

Retrospective cohort study with matched control group.

SETTING

Tertiary perinatal centre.

PATIENTS AND OUTCOME MEASURES

We compared longitudinally collected data on neonatal and neurodevelopmental outcomes among 41 infants born in our institution from 1997 to 2010 with birth weight <1500 g and UA AREDF and 41 infants with prenatally normal UA Doppler parameters matched for gestational age, birth weight, sex and year of birth. We evaluated neurodevelopmental outcome at a median (range) corrected age of 23.3 (10.1-29.6) months using the Bayley scales of infant development, 2nd edition (BSID-II), and neurological examination.

RESULTS

The mental development index in UA AREDF children (median (range) 84 (49-116)) was significantly lower than in controls (median (range) 91 (62-140)), including after adjustment for confounders. Intergroup differences in psychomotor development index (PDI; BSID-II) and the rate of cerebral palsy or minor neuromotor dysfunction were non-significant.

CONCLUSIONS

VLBW infants with UA AREDF have a higher risk of poorer mental development during toddlerhood than controls matched for gestational age, birth weight, sex and year of birth. UA AREDF may be considered a prenatal predictor of poorer mental development in this population. Long-term follow-up studies with larger cohorts are needed to better evaluate the impact of this prenatal factor on later neurodevelopment.

Efficacy of recombinant human granulocyte colony stimulating factor in very-low-birth-weight infants with early neutropenia

BACKGROUND/PURPOSE

Neutropenia is a risk factor for nosocomial infections (NI) in very-low-birth-weight (VLBW) infants. Although recombinant human granulocyte colony stimulating factor (rhG-CSF) increases the neutrophil counts in neutropenic VLBW infants, its long-term efficacy for early neutropenia (EN) remains unknown.

METHODS

In this case-controlled study, charts of VLBW recipients of rhG-CSF for EN (total neutrophil count <1.5 × 10(9)/L during first 7 days) were reviewed and compared to gestational age, total neutrophil count, and birth weight matched infants unexposed to rhG-CSF.

RESULTS

Twenty-seven infants were identified in each group. Mortality and morbidity did not differ between the two groups. Rate of NI (16/27 vs. 4/27, p = 0.002, odds ratio = 8.36) as well as the total number of episodes of NI (22 vs. 4, p = 0.007) were higher in rhG-CSF (+) group than in the rhG-CSF (-) group.

CONCLUSION

Our experience does not show benefit in empirical use of rhG-CSF in preventing NI in VLBW infants with EN.

Enhanced feeding and diminished postnatal growth failure in very-low-birth-weight infants

OBJECTIVE

The aim of the present study was to determine whether an increased supply of energy, protein, essential fatty acids, and vitamin A reduces postnatal growth failure in very-low-birth-weight infants.

METHODS

Fifty infants with birth weight <1500 g were randomized to an intervention (n = 24) or a control (n = 26) feeding protocol within 24 hours after birth. Forty-four infants were included in the final analysis. This study was discontinued because of an increased occurrence of septicemia in the intervention group.

RESULTS

The intervention group had a lower mean birth weight (P = 0.03) and a higher proportion of infants small-for-gestational age (P = 0.04) than the control group. Other baseline characteristics were similar. The median (interquartile range) energy and protein supplies during the first 4 weeks of life were higher in the intervention group: 139 (128-145) versus 126 (121-128) kcal · kg · day (P < 0.001) and 4.0 (3.9-4.2) versus 3.2 (3.1-3.3) g · kg · day (P < 0.001). The infants in the intervention group regained birth weight faster (P = 0.001) and maintained their z scores for weight and head circumference from birth to 36 weeks' postmenstrual age (both P < 0.001). The median (interquartile range) growth velocity was 17.4 (16.3-18.6) g · kg · day in the intervention group and 13.8 (13.2-15.5) g · kg · day in the control group (P < 0.001). In line with the improved growth in the intervention group, the proportion of growth-restricted infants was 11 of 23 both at birth and at 36 weeks' postmenstrual age, whereas this proportion increased among the controls from 4 of 21 to 13 of 21 (P = 0.04).

CONCLUSIONS

Enhanced supply of energy, protein, essential fatty acids, and vitamin A caused postnatal growth along the birth percentiles for both weight and head circumference.

Short-term outcome of pulmonary hemorrhage in very-low-birth-weight preterm infants

BACKGROUND

Severe pulmonary hemorrhage is a serious complication with a high mortality rate in preterm infants with respiratory distress syndrome (RDS) after surfactant therapy. The aim of this study is to evaluate the efficacy of our current management strategy for neonates with severe pulmonary hemorrhage.

MATERIALS AND METHODS

Very-low-birth-weight (VLBW) infants who developed severe pulmonary hemorrhage were studied from January 2006 to August 2011. Treatment for severe pulmonary hemorrhage in our neonatal intensive care unit (NICU) included intratracheal epinephrine spraying/irrigation, blood component therapy, and as necessary, surfactant supplement therapy was administered in cases that secondary RDS was diagnosed. High frequency oscillatory ventilation (HFOV) was utilized when hypoxia or respiratory acidosis persisted under conventional mechanical ventilation (CMV). We then described the clinical courses of severe pulmonary hemorrhage following our management.

RESULTS

A total of 18 (3.2%) out of 469 VLBW infants developed severe pulmonary hemorrhage. The mean gestational age was 27 weeks, the mean birth weight was 822 g, and the onset age was 2.5 days after birth. There was no severe pulmonary hemorrhage-associated mortality during this period with the exception of one case, in which an infant died after the parents refused to do further therapy. Sixteen (88.8%) neonates had RDS and 13 received surfactant therapy. Twelve (66.6%) cases developed secondary RDS following the onset of severe pulmonary hemorrhage, and four cases received surfactant supplement therapy. In the surfactant supplement group, alveolar-arterial oxygen difference (AaDO2) and oxygenation index (OI) during the 2-4 hours postpulmonary hemorrhage period showed statistically significant improvement, whereas the other group only showed a tendency toward improvement without reaching statistical significance when compared to the baseline data. Duration of high oxygen requirement [defined as fraction of inspired oxygen (FiO2) > 40%] was also less in the surfactant supplement group.

CONCLUSION

This data suggests that our current strategy is effective for treating severe pulmonary hemorrhage in VLBW infants. Surfactant therapy for severe pulmonary hemorrhage may also be beneficial for improving lung function and may shorten the duration of high oxygen requirement.

Brain microstructural development at near-term age in very-low-birth-weight preterm infants: an atlas-based diffusion imaging study

At near-term age the brain undergoes rapid growth and development. Abnormalities identified during this period have been recognized as potential predictors of neurodevelopment in children born preterm. This study used diffusion tensor imaging (DTI) to examine white matter (WM) microstructure in very-low-birth-weight (VLBW) preterm infants to better understand regional WM developmental trajectories at near-term age. DTI scans were analyzed in a cross-sectional sample of 45 VLBW preterm infants (BW≤1500g, GA≤32weeks) within a cohort of 102 neonates admitted to the NICU and recruited to participate prior to standard-of-care MRI, from 2010 to 2011, 66/102 also had DTI. For inclusion in this analysis, 45 infants had DTI, no evidence of brain abnormality on MRI, and were scanned at PMA ≤40weeks (34.7-38.6). White matter microstructure was analyzed in 19 subcortical regions defined by DiffeoMap neonatal brain atlas, using threshold values of trace <0.006mm(2)s(-1) and FA >0.15. Regional fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated and temporal-spatial trajectories of development were examined in relation to PMA and brain region location. Posterior regions within the corona radiata (CR), corpus callosum (CC), and internal capsule (IC) demonstrated significantly higher mean FA values compared to anterior regions. Posterior regions of the CR and IC demonstrated significantly lower RD values compared to anterior regions. Centrally located projection fibers demonstrated higher mean FA and lower RD values than peripheral regions including the posterior limb of the internal capsule (PLIC), cerebral peduncle, retrolenticular part of the IC, posterior thalamic radiation, and sagittal stratum. Centrally located association fibers of the external capsule had higher FA and lower RD than the more peripherally-located superior longitudinal fasciculus (SLF). A significant relationship between PMA-at-scan and FA, MD, and RD was demonstrated by a majority of regions, the strongest correlations were observed in the anterior limb of the internal capsule, a region undergoing early stages of myelination at near-term age, in which FA increased (r=.433, p=.003) and MD (r=-.545, p=.000) and RD (r=-.540, p=.000) decreased with PMA-at-scan. No correlation with PMA-at-scan was observed in the CC or SLF, regions that myelinate later in infancy. Regional patterns of higher FA and lower RD were observed at this near-term age, suggestive of more advanced microstructural development in posterior compared to anterior regions within the CR, CC, and IC and in central compared to peripheral WM structures. Evidence of region-specific rates of microstructural development was observed. Temporal-spatial patterns of WM microstructure development at near-term age have important implications for interpretation of near-term DTI and for identification of aberrations in typical developmental trajectories that may signal future impairment.