Challenges in Advancing Necrotizing Enterocolitis Research

The incidence and modifiable risk factors for necrotizing enterocolitis in preterm infants: a retrospective cohort study

OBJECTIVES

To evaluate the incidence and modifiable risk factors for Necrotizing enterocolitis (NEC) in preterm infants born at ≤32 weeks of gestation weighing <1500 grams, at a private tertiary care hospital in Kenya.

MATERIALS AND METHODS

This retrospective cohort study was conducted at the Aga Khan University Hospital Neonatal Intensive Care Unit (NICU). Preterm infants born at ≤ 32 weeks' gestation and weighing <1500 grams admitted to NICU between 2009 and 2019, were recruited into the study. The primary outcome was NEC Bell Stage IIa-IIIb based on Modified Bell's criteria. Maternal and neonatal characteristics were evaluated. The association between variables of interest and NEC was determined using logistic regression analysis and the incidence of NEC for the study period was calculated.

RESULTS

A total of 261 charts of infants born at ≤ 32 weeks' gestation, weighing <1500 were reviewed, and 200 charts met the inclusion criteria. Fifteen preterm infants developed the primary outcome of interest: NEC Stage ≥2a within the first 30 days of admission. The overall incidence of NEC for the study period was 7.5%. Three risk factors were identified as significantly associated with NEC on multivariate logistic regression analysis: antenatal exposure to steroids (OR = 0.056 CI = 0.003-0.964 p = 0.047), cumulative duration of exposure to invasive mechanical ventilation (OR = 2.172 CI = 1.242-3.799 p = 0.007) and cumulative duration of exposure to umbilical vein catheter (OR = 1.344 CI = 1.08-1.672 p = 0.008).

CONCLUSIONS

The overall incidence for the study period of NEC Stage ≥ II a was 7.5%. Exposure to antenatal steroids, duration of mechanical ventilation, and duration of umbilical vein catheterization were three independent modifiable risk factors for NEC Stage II a-Stage III b.

Reduction of absolute monocyte counts is associated with the severity of preterm necrotizing enterocolitis

OBJECTIVE

Necrotizing enterocolitis (NEC) is characterized by a rich infiltration of macrophages in the intestines, which is derived from monocytes in the blood. The authors aimed to explore the changing trend of absolute monocyte counts (AMC) over time in NEC infants and to verify whether the reduction of AMC correlates with the severity of NEC and whether it can be used to identify infants who need surgery.

METHOD

The authors collected the clinical data of 66 control and 222 NEC infants. The NEC infants were divided into medical NEC (M-NEC) and surgical NEC (S-NEC). The counting of monocyte and their percentage change were compared at the time of birth, before NEC (baseline), the onset of NEC and after NEC (recovery). In addition, the same comparison was made among stages 1, 2 and 3 of Bell's staging, respectively.

RESULTS

The authors found that the AMC in NEC infants decreased sharply at the onset. Further comparison was made between 172 cases of M-NEC and 50 cases of S-NEC. It was discovered that the AMC reduced more in S-NEC infants at onset, but it increased more at recovery. In addition, the authors found that among stage 1,2 and 3, stage 3 had the lowest AMC and the largest percentage decrease at the onset.

CONCLUSION

The AMC decreases sharply in NEC infants at onset, and the degree of decline is associated with the severity of NEC. AMC is expected to be a marker of NEC and provide a reference for clinicians in the diagnosis and treatment of NEC.

A pressing need for research to reduce nutritional uncertainties in preterm infant care: Findings from a European roundtable discussion with parent representatives

INTRODUCTION

Other than for agreement that own mother's milk is the optimum feed, nutritional practice for very preterm babies varies widely. As part of the development of a randomised controlled trial to address preterm nutrition uncertainties, and with the help of the European Foundation for the Care of Newborn Infants (EFCNI), we sought the views of parents across Europe.

METHODS

We held two roundtable discussions about the proposed trial, inviting the participation of parents and preterm adults through EFCNI. We sought their views and prior knowledge of preterm nutrition uncertainties, treatment comparisons and opinions on specific aspects of design such as cluster versus individual randomisation. We used thematic Framework Analysis to explore the data.

RESULTS

There were 11 participants (two men and nine women) from six European countries. Nine were parents and two were preterm adults. Participants strongly supported the need for research to improve care. However, we found little knowledge of methods to resolve uncertainties in care, and wide variation in information provided to parents during their baby's neonatal unit stay. No parent recalled a member of the clinical staff having told them about nutrition uncertainties.

CONCLUSIONS

Present-day best practice is to involve parents, patients, and the public in all stages of clinical research from design to dissemination and implementation. To strengthen involvement and participation we suggest there is need to improve knowledge of research methods. Clinicians may find it helpful to receive training on how to explain clinical uncertainties, and methods to resolve these.

Protective effects of different doses of human milk on neonatal necrotizing enterocolitis

We aim to summarize the evidence focusing on the effects of various doses of human milk on the risk of neonatal necrotizing enterocolitis (NEC). The eligible articles in the study were those investigating the association between human milk and NEC published before June 26, 2019, in the PubMed, EMBASE, the Cochrane Library, VIP database, CNKI database, and Wangfang database. The included criteria were as follows: premature infants of <37 weeks; randomly controlled trials (RCTs); those fed by mother's own milk or donor human milk; studies focused on the comparison of human milk and formula milk, involving various breast milk doses; and NEC-related studies. Compared with the exclusive formula, the incidence of NEC in the infants fed by exclusive human milk was significantly lower. The incidence of NEC in the infants fed by exclusive human milk was significantly lower than that of partial human milk [risk ratio (RR) = 0.54, 95% confidence interval (95% CI): 0.36-0.79, P < .05]. The incidence of NEC in the infants fed mainly by human milk was significantly lower than that of mainly fed by formula. Incidence of NEC in the infants fed by exclusive human milk was significantly lower than that of any formula (RR = 0.49, 95% CI: 0.34-0.71, P < .05). In summary, this meta-analysis was based on the RCTs involving the prevention of NEC using human milk. Exclusive human milk and partial human milk reduced the incidence of NEC in premature infants, especially in the those fed by high proportion of human milk. In addition, more RCTs are needed to further validate such conclusion.

Probiotics and Preterm Infants: A Position Paper by the European Society for Paediatric Gastroenterology Hepatology and Nutrition Committee on Nutrition and the European Society for Paediatric Gastroenterology Hepatology and Nutrition Working Group for Probiotics and Prebiotics

More than 10,000 preterm infants have participated in randomised controlled trials on probiotics worldwide, suggesting that probiotics in general could reduce rates of necrotising enterocolitis (NEC), sepsis, and mortality. Answers to relevant clinical questions as to which strain to use, at what dosage, and how long to supplement are, however, not available. On the other hand, an increasing number of commercial products containing probiotics are available from sometimes suboptimal quality. Also, a large number of units around the world are routinely offering probiotic supplementation as the standard of care despite lacking solid evidence. Our recent network meta-analysis identified probiotic strains with greatest efficacy regarding relevant clinical outcomes for preterm neonates. Efficacy in reducing mortality and morbidity was found for only a minority of the studied strains or combinations. In the present position paper, we aim to provide advice, which specific strains might potentially be used and which strains should not be used. In addition, we aim to address safety issues of probiotic supplementation to preterm infants, who have reduced immunological capacities and occasional indwelling catheters. For example, quality reassurance of the probiotic product is essential, probiotic strains should be devoid of transferable antibiotic resistance genes, and local microbiologists should be able to routinely detect probiotic sepsis. Provided all safety issues are met, there is currently a conditional recommendation (with low certainty of evidence) to provide either Lactobacillus rhamnosus GG ATCC53103 or the combination of Bifidobacterium infantis Bb-02, Bifidobacterium lactis Bb-12, and Streptococcus thermophilus TH-4 in order to reduce NEC rates.

The constitution and functional prediction of the microbiota in necrotizing enterocolitis with a gestational age of over 28 weeks

BACKGROUND

To explore the features and function of gut microbiota in necrotizing enterocolitis patients over 28 gestational age weeks through a case-control study.

METHODS

Fecal samples from patients with NEC over 28 gestational week age and matched control cases were collected. DNA of the fecal samples was extracted for 16 s rRNA sequencing to estimate the composition of the microbiota. Functional inference analyses were conducted through PICRUSt based on the sequencing raw data.

RESULTS

There was no significant difference in the total diversity of microbiota between the fecal samples from the patients with NEC and the controls (P = .40). Propionibacterium was more abundant in the NEC cases than in the controls. Conversely, Lactobacillus, Phascolarctobacterium, and Streptococcus_salivarius were found to be more plentiful in the controls through LEfSe analysis. Functional inference analysis revealed that the xenobiotic biodegradation and metabolic activity was lower in the NEC cases than in the controls (P < .05).

CONCLUSION

The NEC cohort with a gestational age of over 28 weeks has a different pattern of microbiota compared with the controls. Functional inference analysis indicated that the potential function of the microbiota may also differ between these groups.