Maternal and placental risk factors associated with the development of necrotizing enterocolitis (NEC) and its severity

Maternal chorioamnionitis and the risk for necrotizing enterocolitis in the United States: A national cohort study

BACKGROUND

Necrotizing enterocolitis (NEC) is a major cause for morbidity and mortality among newborn infants. Chorioamnionitis is a perinatal complication that is associated with preterm delivery. Few reports have studied chorioamnionitis as a possible risk factor for NEC. Further investigation is needed to fully understand this association.

OBJECTIVE

To examine the association of chorioamnionitis with NEC in newborn infants.

METHODS

We used National Inpatient Sample (NIS) datasets produced by the federal Healthcare Cost and Utilization Project (HCUP). We identified infants born to mothers diagnosed with chorioamnionitis and infants born to mothers who did not have chorioamnionitis. The odds ratios (OR) to develop NEC in infants born to mothers affected by chorioamnionitis were calculated using chi square and Fisher Exact tests in the overall sample and in subgroups of different birthweight (BW) categories. The association was re-evaluated using logistic regression models to control for confounding variables.

RESULTS

The study identified 18,973,800 newborn infants admitted during the years 2016-2020. Among infants born to mothers with chorioamnionitis, NEC occurred in 0.9 % compared to 0.1 % in infants born to mothers without chorioamnionitis, (adjusted OR = 1.12, CI:1.02-1.15, p = 0.01). The prevalence of NEC in infants born to mothers with chorioamnionitis varied by the birth weight category, mainly for BW category 2500-4499 g (aOR = 1.61, CI:1.44-1.80, p < 0.001).

CONCLUSION

Maternal chorioamnionitis is associated with increased incidence of NEC, particularly in the BW category 2500-4499 g. Further studies are needed to examine the pathophysiological factors underlying this association.

Prevalence and risk factors associated with the need for surgical intervention due to necrotizing enterocolitis in very low birth weight infants

INTRODUCTION

Necrotizing enterocolitis (NEC) is one of the most common gastrointestinal emergencies affecting very low birth weight (VLBW) infants with an incidence of 6-15 %. Early recognition is crucial. Mortality is high and variable (30-50 %). Those requiring surgical intervention have a higher mortality rate than those who receive medical treatment.

OBJECTIVES

1) To assess the prevalence of surgical NEC and associated risk factors 2) To compare outcomes based on the type of treatment required 3) To estimate the mortality associated with NEC and surgical NEC.

METHODS

A multicentre retrospective cohort study was designed (level II), including VLBW infants born between 2011 and 2020 in Centers of the Neocosur Network. A multivariate logistic regression analysis was performed to evaluate risk factors associated with the need for surgery.

RESULTS

NEC was diagnosed in 1679 (10.4 %) of 16,131 births in this period. The prevalence of surgery was 25 % (95 % CI 23-27 %). In multivariable analysis, variables associated with an increased risk of surgery requirement were birth weight <750 g (aOR 1.73-95%CI 1.2-2.5) and receiving antenatal antibiotics (aOR 1.54-95%CI 1.09-2.74). Those requiring surgery had significantly higher morbidity and mortality than the ones receiving medical treatment.

CONCLUSION

In VLBW infants with NEC, lower birth weight and antenatal antibiotics administration were independently associated with the need for surgical intervention.

A key role for NLRP3 signaling in preterm labor and birth driven by the alarmin S100B

Preterm birth remains the leading cause of neonatal morbidity and mortality worldwide. A substantial number of spontaneous preterm births occur in the context of sterile intra-amniotic inflammation, a condition that has been mechanistically proven to be triggered by alarmins. However, sterile intra-amniotic inflammation still lacks treatment. The NLRP3 inflammasome has been implicated in sterile intra-amniotic inflammation; yet, its underlying mechanisms, as well as the maternal and fetal contributions to this signaling pathway, are unclear. Herein, by utilizing a translational and clinically relevant model of alarmin-induced preterm labor and birth in Nlrp3-/- mice, we investigated the role of NLRP3 signaling by using imaging and molecular biology approaches. Nlrp3 deficiency abrogated preterm birth and the resulting neonatal mortality induced by the alarmin S100B by impeding the premature activation of the common pathway of labor as well as by dampening intra-amniotic and fetal inflammation. Moreover, Nlrp3 deficiency altered leukocyte infiltration and functionality in the uterus and decidua. Last, embryo transfer revealed that maternal and fetal Nlrp3 signaling contribute to alarmin-induced preterm birth and neonatal mortality, further strengthening the concept that both individuals participate in the complex process of preterm parturition. These findings provide novel insights into sterile intra-amniotic inflammation, a common etiology of preterm labor and birth, suggesting that the adverse perinatal outcomes resulting from prematurity can be prevented by targeting NLRP3 signaling.

The Impact of Stress, Microbial Dysbiosis, and Inflammation on Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the leading cause of intestinal morbidity and mortality in neonates. A large body of work exists; however, the pathogenesis of NEC remains poorly understood. Numerous predictors have been implicated in the development of NEC, with relatively less emphasis on maternal factors. Utilizing human tissue plays a crucial role in enhancing our comprehension of the underlying mechanisms accountable for this devastating disease. In this review, we will discuss how maternal stress affects the pathogenesis of NEC and how changes in the intestinal microbiome can influence the development of NEC. We will also discuss the results of transcriptomics-based studies and analyze the gene expression changes in NEC tissues and other molecular targets associated with the pathogenesis of NEC.

What animal model should I use to study necrotizing enterocolitis?

Unfortunately, we are all too familiar with the statement: "Necrotizing enterocolitis remains the leading cause of gastrointestinal surgical emergency in preterm neonates". It's been five decades since the first animal models of necrotizing enterocolitis (NEC) were described. There remains much investigative work to be done on identifying various aspects of NEC, ranging from the underlying mechanisms to treatment modalities. Experimental NEC is mainly focused on a rat, mouse, and piglet models. Our aim is to not only highlight the pros and cons of these three main models, but to also present some of the less-used animal models that have contributed to the body of knowledge about NEC. Choosing an appropriate model is essential to conducting effective research and answering the questions asked. As such, this paper reviews some of the variations that come with each model.

Leveraging the placenta to advance neonatal care

The impact of placental dysfunction and placental injury on the fetus and newborn infant has become a topic of growing interest in neonatal disease research. However, the use of placental pathology in directing or influencing neonatal clinical management continues to be limited for a wide range of reasons, some of which are historical and thus easily overcome today. In this review, we summarize the most recent literature linking placental function to neonatal outcomes, focusing on clinical placental pathology findings and the most common neonatal diagnoses that have been associated with placental dysfunction. We discuss how recent technological advances in neonatal and perinatal medicine may allow us to make a paradigm shift, in which valuable information provided by the placenta could be used to guide neonatal management more effectively, and to ultimately enhance neonatal care in order to improve our patient outcomes. We propose new avenues of clinical management in which the placenta could serve as a diagnostic tool toward more personalized neonatal intensive care unit management.

Association of Placental Pathologic Findings with the Severity of Necrotizing Enterocolitis in Preterm infants - A Matched Case-Control Study

OBJECTIVE

To determine the association of placental pathology with the severity of necrotizing enterocolitis (NEC) in preterm infants.

METHODS

This single-center matched case-control study included infants with NEC (n = 107) and gestational age and birth weight-matched controls (n = 130), born between 2013 and 2020. Placentas were evaluated according to the Amsterdam Placental Workshop Group Consensus Statement.

RESULTS

Acute histologic chorioamnionitis with the fetal response was significantly more common in infants with surgical NEC vs. medical NEC (35.4% vs. 15.3%; p = 0.02). On regression model, infants with multiple placental pathologies (OR 2.16; 95% CI 1.01 - 4.73; p = 0.04) and maternal vascular malperfusion (OR 2.2; 95% CI 1.12 - 4.51; p = 0.02) had higher odds of either medical or surgical NEC than controls.

CONCLUSION

Infants with multiple placental lesions, including placental inflammatory and vascular lesions, were at higher risk of medical or surgical NEC in the postnatal period.

Impact of maternal factors, environmental factors, and race on necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a complex disease with a multifactorial etiology. As the leading cause of intestinal morbidity and mortality among premature infants, many resources are being dedicated to neonatal care and molecular targets in the newborn intestine. However, NEC is heavily influenced by maternal and perinatal factors as well. Given its nature, preventive approaches to NEC are more likely to improve outcomes than new treatment strategies. Therefore, this review focuses on maternal, environmental, and racial factors associated with the development of NEC, with an emphasis on those that may be modifiable to decrease the incidence of the disease.

Necrotizing Enterocolitis: The Role of Hypoxia, Gut Microbiome, and Microbial Metabolites

Necrotizing enterocolitis (NEC) is a life-threatening disease that predominantly affects very low birth weight preterm infants. Development of NEC in preterm infants is accompanied by high mortality. Surgical treatment of NEC can be complicated by short bowel syndrome, intestinal failure, parenteral nutrition-associated liver disease, and neurodevelopmental delay. Issues surrounding pathogenesis, prevention, and treatment of NEC remain unclear. This review summarizes data on prenatal risk factors for NEC, the role of pre-eclampsia, and intrauterine growth retardation in the pathogenesis of NEC. The role of hypoxia in NEC is discussed. Recent data on the role of the intestinal microbiome in the development of NEC, and features of the metabolome that can serve as potential biomarkers, are presented. The Pseudomonadota phylum is known to be associated with NEC in preterm neonates, and the role of other bacteria and their metabolites in NEC pathogenesis is also discussed. The most promising approaches for preventing and treating NEC are summarized.

Fetal Doppler Evaluation to Predict NEC Development

Antenatal factors play a role in NEC pathogenesis. This study aimed to investigate the predictive value of fetal ductus venosus doppler (DV) for NEC in fetal growth restriction fetuses (FGRF) and to assess the predictive accuracy of IG21 and Fenton curves in NEC development. Data from FGRF, postnatal findings, and Doppler characteristics were collected between 2010 and 2020 at a single center. Patients were then divided into two groups (i.e., with and without NEC). Bivariate and multivariate analyses were performed. We identified 24 cases and 30 controls. Absent or reversed end-diastolic flow (AREDF) and increased resistance in the DV were more impaired in cases (p < 0.05). Although the median birthweight was not different, the Fenton z-score was lower in NEC (p < 0.05). Fetal cardiopulmonary resuscitation, synchronized intermittent mandatory ventilation, neonatal respiratory distress, persistent patent ductus arteriosus (PDA), and inotropic support were more frequent in the NEC group. Furthermore, NEC patients had lower white blood cells (WBC) (p < 0.05). The predictive model for NEC (model 4), including Fenton z-score, WBC, PDA, and DV had an AUC of 84%. Fetal Doppler findings proved effective in predicting NEC in FGR. The Fenton z-score was the most predictive factor considering the fetal growth assessment showing high sensitivity.

Necrotizing Enterocolitis and Its Predictors Among Preterm Neonates Admitted in Neonatal Intensive Care Units of Gurage Zone Public Hospitals, Southwest Ethiopia, 2021

Background

Necrotizing Enter colitis (NEC) is the most common multifactorial and devastating gastrointestinal emergency which primarily affects premature infants. The purpose of this study was to identify the prevalence of Necrotizing Enterocolitis and its associated factors among preterm neonates admitted to Neonatal Intensive Care Units in Gurage Zone hospitals.

Methods

Institution-based cross-sectional study design was employed. The simple Random Sampling Technique was applied to collect the data using a structured questionnaire. Data were cleaned, checked for inconsistencies, coded and entered via EPI data 3.1, and exported to Stata version 14 for further analysis. The data were processed by Stata 14 to estimate the prevalence of necrotizing enterocolitis.

Results

The prevalence of Necrotizing Enterocolitis among neonates was 28 (9.7%) 95% CI of 6. 8–13.7%. Birth weight (AOR: 7.33 95% CI (2.04: 26.38)), presence of maternal infection (AOR: 6.09, 95% CI (1.31:28.26)), length of hospital stay (AOR: 3.28, 95% CI (1.20, 8.96)), and initiating trophic feeding (AOR: 5.89, 95% CI (2.27: 15.33)) were associated with neonatal necrotizing enterocolitis.

Conclusion

The prevalence of Necrotizing Enterocolitis among preterm neonates was significant and special attention is needed for premature neonates with low birth weight and born from mothers with infection during pregnancy. Minimizing the length of hospital stay will be very useful to prevent the occurrence of Necrotizing Enterocolitis.

Placental histology predicted adverse outcomes in extremely premature neonates in Norway-population-based study

AIM

We evaluated the role of placental pathology in predicting adverse outcomes for neonates born extremely preterm (EPT) before 28 weeks of gestation.

METHODS

This was a prospective observational study of 123 extremely preterm singletons born in a hospital in western Norway, and the placentas were classified according to the Amsterdam criteria. The associations between histologic chorioamnionitis (HCA), by the presence or the absence of a foetal inflammatory response (FIR+ or FIR-), maternal vascular malperfusion (MVM) as a whole and adverse neonatal outcomes were evaluated by logistic regression analyses. Adverse outcomes were defined as perinatal death, necrotising enterocolitis (NEC), bronchopulmonary dysplasia (BPD), brain pathology by magnetic resonance imaging at term-equivalent age, retinopathy of prematurity and early-onset neonatal sepsis. The results are reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

HCA was associated with NEC (OR 12.2, 95% CI 1.1 to 137.1). HCA/FIR+ was associated with BPD (OR 14.9, 95% CI 1.8-122.3) and brain pathology (OR 9.8, 95% CI 1.4-71.6), but HCA/FIR- was not. The only neonatal outcome that MVM was associated with was low birthweight.

CONCLUSION

Placental histology provided important information when assessing the risk of adverse neonatal outcomes following EPT birth.

Necrotizing Enterocolitis in Preterm Infants Born to Mother with COVID-19

Background: The COVID-19 pandemic has had a wide impact on both pregnant women and their babies. Necrotizing enterocolitis (NEC) is a gastrointestinal emergency in neonates with high morbidity and mortality. Objective: This study aims to investigate the incidence of NEC in preterm infants born to mothers with confirmed COVID-19. Methods: This observational study was conducted in neonatal intensive care unit at Dr. Soetomo General Academic Hospital, Surabaya, Indonesia, from May 2020 to April 2021. All preterm infants born to mothers with positive COVID-19 based on swab examination were included as study participants. PCR swab examination was performed within 48 hours after birth. The diagnosis of COVID-19 was defined as positive if the swab test result could detect the SARS-CoV-2 virus. The diagnosis of NEC was established by clinical symptoms and confirmed by abdominal radiography. Results: Out of 45 preterm infants included in this study, 6 infants experienced NEC. Factors that were significantly associated with the incidence of NEC included asphyxia and intubated mother. Positive PCR results from the infants alone did not significantly increase the risk of NEC. The combination of asphyxia and intubated mother (Odds Ratio [OR]=10.000, 95% Confidence Interval [CI]=1.056-94.677, P=0.020) and the combination of positive PCR result, asphyxia, and intubated mother (OR=2.438, 95% CI=1.673-3.551, P=0.007) were found to be significantly associated with the incidence of NEC Conclusion: Significant factors associated with the incidence of NEC in preterm infants born to mothers with COVID-19 included asphyxia and intubated mothers prior to delivery. A positive PCR result alone did not significantly increase the risk of NEC.

Potential Prenatal Origins of Necrotizing Enterocolitis

Necrotizing enterocolitis is a serious and yet incompletely understood gastrointestinal disease of infancy that predominately impacts premature neonates. Prevention is a key strategy for the management of necrotizing enterocolitis. Although postnatal risk factors have been the focus of prevention efforts, obstetric complications, including intrauterine inflammation and infection, growth restriction, preeclampsia, and prenatal medications, have been associated with an increased risk of necrotizing enterocolitis. This article reviews the evidence behind the prenatal risk factors for necrotizing enterocolitis, and discusses how these risk factors may elucidate the pathogenesis of necrotizing enterocolitis and provide insight into prevention and treatment.

Maternal aryl hydrocarbon receptor activation protects newborns against necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a disease of premature infants characterized by acute intestinal necrosis. Current dogma suggests that NEC develops in response to post-natal dietary and bacterial factors, and so a potential role for in utero factors in NEC remains unexplored. We now show that during pregnancy, administration of a diet rich in the aryl hydrocarbon receptor (AHR) ligand indole-3-carbinole (I3C), or of breast milk, activates AHR and prevents NEC in newborn mice by reducing Toll-like receptor 4 (TLR4) signaling in the newborn gut. Protection from NEC requires activation of AHR in the intestinal epithelium which is reduced in mouse and human NEC, and is independent of leukocyte activation. Finally, we identify an AHR ligand ("A18") that limits TLR4 signaling in mouse and human intestine, and prevents NEC in mice when administered during pregnancy. In summary, AHR signaling is critical in NEC development, and maternally-delivered, AHR-based therapies may alleviate NEC.

Optimizing Nutritional Strategies to Prevent Necrotizing Enterocolitis and Growth Failure after Bowel Resection

Necrotizing enterocolitis (NEC), the first cause of short bowel syndrome (SBS) in the neonate, is a serious neonatal gastrointestinal disease with an incidence of up to 11% in preterm newborns less than 1500 g of birth weight. The rate of severe NEC requiring surgery remains high, and it is estimated between 20–50%. Newborns who develop SBS need prolonged parenteral nutrition (PN), experience nutrient deficiency, failure to thrive and are at risk of neurodevelopmental impairment. Prevention of NEC is therefore mandatory to avoid SBS and its associated morbidities. In this regard, nutritional practices seem to play a key role in early life. Individualized medical and surgical therapies, as well as intestinal rehabilitation programs, are fundamental in the achievement of enteral autonomy in infants with acquired SBS. In this descriptive review, we describe the most recent evidence on nutritional practices to prevent NEC, the available tools to early detect it, the surgical management to limit bowel resection and the best nutrition to sustain growth and intestinal function.

[Influence of premature rupture of membranes on the early prognosis of extremely premature infants]

OBJECTIVE

To study the influence of premature rupture of membranes (PROM) on the early prognosis of extremely premature infants, and to provide a basis for the management of extremely premature infants and prenatal consultation.

METHODS

A total of 179 extremely premature singleton infants who were born from 2017 to 2019 were enrolled. According to the presence or absence of PROM, they were divided into two groups: PROM group (n=69) and non-PROM group (n=110). A statistical analysis was performed for maternal data and early prognostic indicators.

RESULTS

Compared with the non-PROM group, the PROM group had significantly higher incidence rates of earlyonset sepsis and necrotizing enterocolitis (NEC) (P < 0.05) and significantly lower rate of use of pulmonary surfactant and incidence rate of hemodynamically significant patent ductus arteriosus (P < 0.05). The multivariate logistic regression analysis showed that chorioamnionitis was an independent risk factor for early-onset sepsis and NEC (OR=11.062 and 9.437 respectively, P < 0.05), and PROM was an independent protective factor against the use of pulmonary surfactant (OR=0.363, P < 0.05).

CONCLUSIONS

PROM increases the incidence rates of early-onset sepsis and NEC in extremely premature infants and does not increase the incidence rates of other adverse outcomes. For pregnant women with PROM at the risk of extremely preterm delivery, prevention of miscarriage and chorioamnionitis is recommended to prolong gestational weeks, reduce the incidence rate of infection, and thus improve the outcome of extremely premature infants.

Case report: necrotizing enterocolitis with a transverse colonic perforation in a 2-day old term neonate and literature review

BACKGROUND

Necrotizing enterocolitis (NEC), while classically discussed in preterm and low birth weight neonates, also occurs in the term infant and accounts for 10% of all NEC cases. Despite there being fewer reported cases of NEC in term infants, these presentations demonstrate differences in the onset, severity and risk factors from the classic presentation observed in premature infants. We present a novel case of term NEC that contravenes the reported literature making departures from clinical presentation, risk factors and location of perforation in an otherwise healthy term two-day old infant born after an uncomplicated pregnancy who presented with hematochezia.

CASE PRESENTATION

A healthy term baby born after an uneventful pregnancy presented with bloody stool at 2 days of life who was otherwise well. Investigations revealed pneumoperitoneum from a large proximal transverse colonic perforation secondary to NEC. No typical risk factors for NEC were found.

CONCLUSION

Given the life-threatening potential of an unrecognized perforation we recommend the inclusion of NEC on the differential for neonatal hematochezia.

Pathological staging of chorioamnionitis contributes to complications in preterm infants

Objective

To investigate the effect of pathological staging of chorioamnionitis (CA) on complications in preterm infants;

Methods

A single-center, retrospective study was conducted to choose singleton preterm infants (gestational age < 37 weeks) from the Department of Obstetrics and Gynecology in our hospital from December 2016 to December 2017. The basic data and placental pathological results were retrospectively collected. According to the placental pathological results of whether inflammation infiltrating amnion, CA 0/I phase was classified into non-amnionitis group, CA II/III phase was classified into amnionitis group, the incidence of common complications in preterm infants was compared. Further, logistic regression was used to analyze the effects of amnionitis on complications after being adjusted to gestational age, birth weight and thrombocytopenia.

Results

A total of 221 preterm infants were enrolled, including 186 cases in non-amnionitis group and 35 cases in amnionitis group. The gestational age of amnionitis group (32.00 ± 2.71 weeks) was significantly lower than non-amnionitis group (34.14 ± 2.06 weeks), birth weight (1.93 ± 0.64 kg) was significantly lower than that of non-amnionitis group (2.26 ± 0.58 kg), and the hospital stay in amnionitis group was significantly longer (25.71 ± 19.23 days), all of the difference above was statistically significant(P < 0.05). The incidence of intraventricular hemorrhage (IVH) in amnionitis group (37.14%) was significantly higher than that in non-amnionitis group (13.98%) (P = 0.002), and the risk of IVH was significantly increased by amnionitis (OR = 3.636, 95%CI: 1.632–8.102); after correction of gestational age, birth weight and thrombocytopenia, the risk of IVH was still significantly increased (OR = 2.471, P = 0.046, 95% CI: 1.015–6.015). And the late-onset IVH was more common (P = 0.009).

Conclusion

Amnionitis leads to a significant reduction in gestational age and birth weight in preterm infants, and it is an independent risk factor for IVH.

Emerging Biomarkers for Prediction and Early Diagnosis of Necrotizing Enterocolitis in the Era of Metabolomics and Proteomics

Necrotizing Enterocolitis (NEC) is a catastrophic disease affecting predominantly premature infants and is characterized by high mortality and serious long-term consequences. Traditionally, diagnosis of NEC is based on clinical and radiological findings, which, however, are non-specific for NEC, thus confusing differential diagnosis of other conditions such as neonatal sepsis and spontaneous intestinal perforation. In addition, by the time clinical and radiological findings become apparent, NEC has already progressed to an advanced stage. During the last three decades, a lot of research has focused on the discovery of biomarkers, which could accurately predict and make an early diagnosis of NEC. Biomarkers used thus far in clinical practice include acute phase proteins, inflammation mediators, and molecules involved in the immune response. However, none has been proven accurate enough to predict and make an early diagnosis of NEC or discriminate clinical from surgical NEC or other non-NEC gastrointestinal diseases. Complexity of mechanisms involved in NEC pathogenesis, which remains largely poorly elucidated, could partly explain the unsatisfactory diagnostic performance of the existing NEC biomarkers. More recently applied technics can provide important insight into the pathophysiological mechanisms underlying NEC but can also aid the detection of potentially predictive, early diagnostic, and prognostic biomarkers. Progress in omics technology has allowed for the simultaneous measurement of a large number of proteins, metabolic products, lipids, and genes, using serum/plasma, urine, feces, tissues, and other biological specimens. This review is an update of current data on emerging NEC biomarkers detected using proteomics and metabolomics, further discussing limitations and future perspectives in prediction and early diagnosis of NEC.