The antecedents and correlates of necrotizing enterocolitis and spontaneous intestinal perforation among infants born before the 28th week of gestation

Neonatal Necrotizing Enterocolitis: An Update on Pathophysiology, Treatment, and Prevention

Necrotizing enterocolitis (NEC) is a life-threatening disease predominantly affecting premature and very low birth weight infants resulting in inflammation and necrosis of the small bowel and colon and potentially leading to sepsis, peritonitis, perforation, and death. Numerous research efforts have been made to better understand, treat, and prevent NEC. This review explores a variety of factors involved in the pathogenesis of NEC (prematurity, low birth weight, lack of human breast milk exposure, alterations to the microbiota, maternal and environmental factors, and intestinal ischemia) and reports treatment modalities surrounding NEC, including pain medications and common antibiotic combinations, the rationale for these combinations, and recent antibiotic stewardship approaches surrounding NEC treatment. This review also highlights the effect of early antibiotic exposure, infections, proton pump inhibitors (PPIs), and H2 receptor antagonists on the microbiota and how these risk factors can increase the chances of NEC. Finally, modern prevention strategies including the use of human breast milk and standardized feeding regimens are discussed, as well as promising new preventative and treatment options for NEC including probiotics and stem cell therapy.

The impact of maternal stress on the development of necrotizing enterocolitis: A comprehensive review

Necrotizing Enterocolitis (NEC) is a devastating intestinal inflammatory disease with significant morbidity and mortality. Numerous predictors have been implicated in the development of NEC, with a relatively less emphasis on maternal factors. Pregnancy drives women into a new stage of life that increases their susceptibility to biological and psychological stress. Additionally, maternal stress during pregnancy has been linked to various complications that can negatively impact both the mother and the developing fetus. These detrimental effects are facilitated by various systemic modifications. Similarly, there is evidence from animal studies that suggest a relationship between maternal stress and the occurrence of NEC due to the alterations observed in neonates. In this review, we will (1) discuss the physiological and psychological burden of maternal stress and how it can be linked to NEC, (2) summarize various predictors and risk factors of NEC, and (3) discuss the most widely utilized animal models for assessing the effects of prenatal stress on offspring.

The contributions of parental lactation on offspring development: It's not udder nonsense!

The Developmental Origins of Health and Disease (DOHaD) hypothesis describes how maternal stress exposures experienced during critical periods of perinatal life are linked to altered developmental trajectories in offspring. Perinatal stress also induces changes in lactogenesis, milk volume, maternal care, and the nutritive and non-nutritive components of milk, affecting short and long-term developmental outcomes in offspring. For instance, selective early life stressors shape the contents of milk, including macro/micronutrients, immune components, microbiota, enzymes, hormones, milk-derived extracellular vesicles, and milk microRNAs. In this review, we highlight the contributions of parental lactation to offspring development by examining changes in the composition of breast milk in response to three well-characterized maternal stressors: nutritive stress, immune stress, and psychological stress. We discuss recent findings in human, animal, and in vitro models, their clinical relevance, study limitations, and potential therapeutic significance to improving human health and infant survival. We also discuss the benefits of enrichment methods and support tools that can be used to improve milk quality and volume as well as related developmental outcomes in offspring. Lastly, we use evidence-based primary literature to convey that even though select maternal stressors may modulate lactation biology (by influencing milk composition) depending on the severity and length of exposure, exclusive and/or prolonged milk feeding may attenuate the negative in utero effects of early life stressors and promote healthy developmental trajectories. Overall, scientific evidence supports lactation to be protective against nutritive and immune stressors, but the benefits of lactation in response to psychological stressors need further investigation.

Antenatal Risk Factors Associated with Spontaneous Intestinal Perforation in Preterm Infants Receiving Postnatal Indomethacin

OBJECTIVE

To determine if antenatal variables affect the risk of spontaneous intestinal perforation (SIP) among preterm infants when prophylactic indomethacin is used.

STUDY DESIGN

Retrospective case-control study of infants <29 weeks of gestational age between January 2010 and June 2018 at one hospital. SIP was defined as acute abdominal distension and pneumoperitoneum without signs of necrotizing enterocolitis at <14 days of life. Each case (n = 57) was matched with 2 controls (n = 114) for gestational age and birth year. Maternal and infant data were abstracted until the SIP or equivalent day for controls. Univariate analyses were followed by adjusted conditional logistic regressions and reported as OR and 95% CI.

RESULTS

Mothers of cases were younger, more often delivering multiples (31% vs 14%, P = .007), and less abruptions (15% vs 29%, P = .045) but did not differ in intra-partum betamethasone, magnesium, or indomethacin use. Prophylactic indomethacin was given on day 1 to 99% of infants. SIP was associated with a shorter interval from last betamethasone dose to delivery (46 hours vs 96 hours, P = .01). Dopamine use (14% vs 4%, P = .02), volume expansion (23% vs 8%, P = .003), and high grade intraventricular hemorrhage (28% vs 8%, P = .0008) were related postnatal factors. The adjusted odds of SIP increased by 1% for each hour decrease between the last dose of betamethasone and delivery (OR 1.01, 95% CI 1.002-1.019) and with multiple births (OR 2.66, 95% CI 1.05-6.77).

CONCLUSIONS

Antenatal betamethasone given shortly before delivery is associated with an increased risk of SIP. Potential interaction with medications such as postnatal indomethacin needs study.

Antenatal magnesium sulfate and intestinal morbidities in preterm infants with extremely low gestational age

BACKGROUND

Antenatal magnesium sulfate is widely used as a tocolytic, for maternal seizures, and for seizure prophylaxis in preeclampsia. Recent studies have suggested that antenatal magnesium sulfate use is associated with favorable neurodevelopmental outcomes in preterm infants. However, there are concerns regarding the effects of antenatal magnesium sulfate on neonates, especially regarding gastrointestinal morbidities. This study aims to explore the effects of antenatal magnesium sulfate on intestinal morbidities requiring surgery in preterm infants.

METHODS

This was a retrospective cohort study of 181 preterm infants who were born at less than 28 weeks of gestational age. Subjects were categorized as infants exposed to antenatal magnesium sulfate and those not exposed to antenatal magnesium sulfate.

RESULTS

Antenatal magnesium sulfate was associated with a decreased risk of surgical conditions of the intestine (OR 0.393, 95% CI 0.170-0.905). The multivariate analysis showed that the duration of antenatal magnesium sulfate use was associated with surgical conditions of the intestine (adjusted OR 0.766, 95% CI 0.589-0.997). In the <26 weeks of gestational age subgroup, the use of antenatal magnesium sulfate was significantly associated with decreased intestinal morbidities requiring surgery (adjusted OR 0.234, 95% CI 0.060-0.922).

CONCLUSION

Antenatal magnesium sulfate use appears to have a protective effect on intestinal morbidities requiring surgery in preterm infants in a duration-dependent manner. Association of antenatal magnesium sulfate use and decreased intestinal morbidities requiring surgery was more distinct in preterm infants <26 weeks of gestational age.

Spontaneous intestinal perforation associated with premature twin infants

OBJECTIVE

Identify perinatal risk factors associated with SIPSTUDY DESIGN:This was a retrospective case-control study of SIP in infants born at ≤28 weeks of gestation and admitted between 1995 and 2016 at a tertiary care NICU. Infants with NEC or other GI abnormalities were excluded. Cases of SIP were matched with gestational age-matched controls with the closest birth date. Maternal, infant and birth related factors were evaluated using univariate analyses and significant factors were evaluated using multiple logistic regression.

RESULT

25 cases of SIP were matched with 25 controls. No maternal factors reached statistical significance. Being one of twins increased the odds of SIP 29-fold. Birth-order or weight-discrepancy in twin had no association of SIP within twin pairs.

CONCLUSION

Twins are at significantly higher risk for SIP. The association of SIP and twin gestation was independent of previously reported risk factors of perinatal indomethacin or magnesium sulfate and merits further study.

Role of Nutrition in Prevention of Neonatal Spontaneous Intestinal Perforation and Its Complications: A Systematic Review

Background: Spontaneous intestinal perforation (SIP) is a devastating complication of prematurity, and extremely low birthweight (ELBW < 1000 g) infants born prior to 28 weeks are at highest risk. The role of nutrition and feeding practices in prevention and complications of SIP is unclear. The purpose of this review is to compile evidence to support early nutrition initiation in infants at risk for and after surgery for SIP. Methods: A search of PubMed, EMBASE and Medline was performed using relevant search terms according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Abstracts and full texts were reviewed by co-first authors. Studies with infants diagnosed with SIP that included information on nutrition/feeding practices prior to SIP and post-operatively were included. Primary outcome was time to first feed. Secondary outcomes were incidence of SIP, time to full enteral feeds, duration of parenteral nutrition, length of stay, neurodevelopmental outcomes and mortality. Results: Nineteen articles met inclusion criteria—nine studies included feeding/nutrition data prior to SIP and ten studies included data on post-operative nutrition. Two case series, one cohort study and sixteen historical control studies were included. Three studies showed reduced incidence of SIP with initiation of enteral nutrition in the first three days of life. Two studies showed reduced mortality and neurodevelopmental impairment in infants with early feeding. Conclusions: Available data suggest that early enteral nutrition in ELBW infants reduces incidence of SIP without increased mortality.

Experimental necrotizing enterocolitis induces neuroinflammation in the neonatal brain

Background

Necrotizing enterocolitis (NEC) is an inflammatory gastrointestinal disease primarily affecting preterm neonates. Neonates with NEC suffer from a degree of neurodevelopmental delay that is not explained by prematurity alone. There is a need to understand the pathogenesis of neurodevelopmental delay in NEC. In this study, we assessed the macroscopic and microscopic changes that occur to brain cell populations in specific brain regions in a neonatal mouse model of NEC. Moreover, we investigated the role of intestinal inflammation as part of the mechanism responsible for the changes observed in the brain of pups with NEC.

Methods

Brains of mice were assessed for gross morphology and cerebral cortex thickness (using histology). Markers for mature neurons, oligodendrocytes, neural progenitor cells, microglia, and astrocytes were used to quantify their cell populations in different regions of the brain. Levels of cell apoptosis in the brain were measured by Western blotting and immunohistochemistry. Endoplasmic reticulum (ER) stress markers and levels of pro-inflammatory cytokines (in the ileum and brain) were measured by RT-qPCR and Western blotting. A Pearson test was used to correlate the levels of cytokines (ELISA) in the brain and ileum and to correlate activated microglia and astrocyte populations to the severity of NEC.

Results

NEC pups had smaller brain weights, higher brain-to-body weight ratios, and thinner cortices compared to control pups. NEC pups had increased levels of apoptosis and ER stress. In addition, NEC was associated with a reduction in the number of neurons, oligodendrocytes, and neural progenitors in specific regions of the brain. Levels of pro-inflammatory cytokines and the density of activated microglia and astrocytes were increased in the brain and positively correlated with the increase in the levels pro-inflammatory cytokines in the gut and the severity of NEC damage respectively.

Conclusions

NEC is associated with severe changes in brain morphology, a pro-inflammatory response in the brain that alters cell homeostasis and density of brain cell populations in specific cerebral regions. We show that the severity of neuroinflammation is associated with the severity of NEC. Our findings suggest that early intervention during NEC may reduce the chance of acute neuroinflammation and cerebral damage.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1481-9) contains supplementary material, which is available to authorized users.

Prediction of intestinal failure from necrotizing enterocolitis following surgery: A multicenter retrospective review

The aim of the present study was to identify risk factors for intestinal failure (IF) in infants who received surgery for necrotizing enterocolitis (NEC).A retrospective multicenter case-series study was conducted in a sample of 91 infants admitted to Children's Hospital of Chongqing Medical University between January 2010 and December 2017. The occurrence of IF was defined as the dependence on parenteral nutrition for ≥90 days. Logistic regression was used to investigate the predictors of IF.Of 179 patients reviewed, excluding those with intestinal malformation and inadequate information, 91 were included in the study, and of these cases, 32 (35.2%) developed IF. Controlling for other factors, multivariate analysis showed that birth weight (OR = 0.999; 95% CI, 0.998-1.000; P = .010), the length of the bowel resected (OR = 1.109; 95% CI, 1.048-1.173; P = .000), and the percentage of small bowel resected (OR = 1.305; 95% CI, 1.133-1.504; P = .000) were factors that increased the chances of IF occurrence.Our data demonstrated that variables characteristic of severe NEC, including lower birth weight, greater extent of bowel resection, and larger percentage of small bowel resection were associated with the incidence of IF.

Isolated Ascites in a Monochorionic Twin after Fetoscopic Laser Ablation Is Not Necessarily Secondary to Recurrence or Anaemia: Bowel Complications in Twin-to-Twin Transfusion Syndrome after Fetoscopic Laser Ablation

BACKGROUND/PURPOSE

We report a case study of jejunal atresia and the results of a systematic literature review of all reported cases of bowel complications occurring after fetoscopic laser ablation (FLA) for the treatment of twin-to-twin transfusion syndrome (TTTS).

METHODS

A systematic literature review was performed of bowel complications after FLA for TTTS according to PRISMA guidelines.

RESULTS

There are 11 published cases of small bowel atresia, 5 cases of necrotising enterocolitis (NEC), and 2 cases with foetal bowel perforations. Recipient twins were more likely to be affected by small bowel atresia (7 recipient and 4 donor cases) and NEC (3 recipient and 2 donor twins). Prenatal ultrasonographic abnormalities were demonstrated in 7 out of 9 cases with bowel atresia and in both cases of bowel perforation. The overall survival rate for neonates with bowel complications after FLA is 72%, but is much lower for co-twins at 22%. The survival rates for jejunoileal atresia and NEC are 91 and 40%, respectively.

CONCLUSIONS

It is uncertain as to whether these bowel anomalies are due to bowel ischaemia associated with TTTS, the treatment with FLA, or a combination of both. Cases with prenatal abdominal ultrasonographic abnormalities after FLA should have close prenatal and postnatal assessment to detect bowel complications.

A critical analysis of risk factors for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common serious gastrointestinal morbidity in preterm infants. A number of risk factors for NEC have been reported in the literature. With the exception of decreasing gestational age, decreasing birth weight and formula feeding, there is disagreement on the importance of reported risk factors with uncertain causality. Causal risk factors may be observed at any time before the onset of NEC, including prior to an infant's birth. The purpose of this review is to examine the existing literature and summarize risk factors for NEC. This review may be helpful in understanding the epidemiology of NEC and inform the measurement and assessment of risks factors for NEC in research studies and quality improvement projects.

Maternal body mass index and risk of intraventricular hemorrhage in preterm infants

BackgroundIntraventricular hemorrhage (IVH) and pre-pregnancy obesity and underweight have been linked to inflammatory states. We hypothesize that IVH in preterm infants is associated with pre-pregnancy obesity and underweight due to an inflammatory intrauterine environment.MethodsPopulation-based study of infants born between 22 and 32 weeks' gestation from 2007 to 2011. Data were extracted from vital statistics and the California Perinatal Quality Care Collaborative. Results were examined for all cases (any IVH) and for severe IVH.ResultsAmong 20,927 infants, 4,818 (23%) had any IVH and 1,514 (7%) had severe IVH. After adjustment for confounders, there was an increased risk of IVH associated with pre-pregnancy obesity, relative risk 1.14 (95% confidence interval (CI) 1.06, 1.32) for any IVH, and 1.25 (85% CI 1.10, 1.42) for severe IVH. The direct effect of pre-pregnancy obesity on any IVH was significant (P<0.001) after controlling for antenatal inflammation-related conditions, but was not significant after controlling for gestational age (P=0.56).ConclusionPre-pregnancy obesity was found to be a risk factor for IVH in preterm infants; however, this relationship appeared to be largely mediated through the effect of BMI on gestational age at delivery. The etiology of IVH is complex and it is important to understand the contributing maternal factors.

Postoperative characteristics of infants who developed necrotizing enterocolitis with different postnatal ages

Our goal was to investigate the surgical procedures, postoperative complications, and survival with regard to different onset timing of necrotizing enterocolitis (NEC).We performed a retrospective review of medical records with a diagnosis of NEC between 2005 and 2016. The cutoff was set at 10 days for early onset ≤10 days and late onset over 10 days. Propensity score matching was performed to adjust for any baseline differences. In 53 paired patients, clinical outcomes, including, mortality, postoperative complications, and length of neonatal intensive care unit (NICU) stay, were evaluated on the basis of early or late-onset NEC.Successful 1:1 matching propensity score matching was performed with 208 infants. Mortality for early-onset NEC infants was lower than that of early late NEC infants (P = .026). A lower overall postoperative complication rate, including infectious complications [19 (35.8) vs 29 (54.7); odds ratio, 0.462, confidence interval (CI) 0.212-1.008, P = .039], was noted in patients with early-onset NEC compared with infants with late-onset NEC. NICU stay and major complication were marginal different between the 2 groups. Comparison of feeding outcomes revealed that the time to achieve full enteral feeds was significantly longer for those with late-onset NEC (18.1 ± 11.5 vs 26.3 ± 15.6, P = .008).The infants who develop NEC after 10 days of life do influence postoperative outcome survival or other clinically important outcomes after laparotomy.

Extremely low gestational age and very low birthweight for gestational age are risk factors for autism spectrum disorder in a large cohort study of 10-year-old children born at 23-27 weeks' gestation

BACKGROUND

No prospective cohort study of high-risk children has used rigorous exposure assessment and optimal diagnostic procedures to examine the perinatal antecedents of autism spectrum disorder separately among those with and without cognitive impairment.

OBJECTIVE

We sought to identify perinatal factors associated with increased risk for autism spectrum disorder with and without intellectual disability (intelligence quotient <70) in children born extremely preterm.

STUDY DESIGN

This prospective multicenter (14 institutions in 5 states) birth cohort study included children born at 23-27 weeks' gestation in 2002 through 2004 who were evaluated for autism spectrum disorder and intellectual disability at age 10 years. Pregnancy information was obtained from medical records and by structured maternal interview. Cervical-vaginal "infection" refers to maternal report of bacterial infection (n = 4), bacterial vaginosis (n = 30), yeast infection (n = 62), mixed infection (n = 4), or other/unspecified infection (n = 43; eg, chlamydia, trichomonas, or herpes). We do not know the extent to which infection per se was confirmed by microbial colonization. We use the terms "fetal growth restriction" and "small for gestational age" interchangeably in light of the ongoing challenge to discern pathologically from constitutionally small newborns. Severe fetal growth restriction was defined as a birthweight Z-score for gestational age at delivery <-2 (ie, ≥2 SD below the median birthweight in a referent sample that excluded pregnancies delivered for preeclampsia or fetal indications). Participants were classified into 4 groups based on whether or not they met rigorous diagnostic criteria for autism spectrum disorder and intellectual disability (autism spectrum disorder+/intellectual disability-, autism spectrum disorder+/intellectual disability+, autism spectrum disorder-/intellectual disability+, and autism spectrum disorder-/intellectual disability-). Temporally ordered multinomial logistic regression models were used to examine the information conveyed by perinatal factors about increased risk for autism spectrum disorder and/or intellectual disability (autism spectrum disorder+/intellectual disability-, autism spectrum disorder+/intellectual disability+, and autism spectrum disorder-/intellectual disability+).

RESULTS

In all, 889 of 966 (92%) children recruited were assessed at age 10 years, of whom 857 (96%) were assessed for autism spectrum disorder; of these, 840 (98%) children were assessed for intellectual disability. Autism spectrum disorder+/intellectual disability- was diagnosed in 3.2% (27/840), autism spectrum disorder+/intellectual disability+ in 3.8% (32/840), and autism spectrum disorder-/intellectual disability+ in 8.5% (71/840). Maternal report of presumed cervical-vaginal infection during pregnancy was associated with increased risk of autism spectrum disorder+/intellectual disability+ (odds ratio, 2.7; 95% confidence interval, 1.2-6.4). The lowest gestational age category (23-24 weeks) was associated with increased risk of autism spectrum disorder+/intellectual disability+ (odds ratio, 2.9; 95% confidence interval, 1.3-6.6) and autism spectrum disorder+/intellectual disability- (odds ratio, 4.4; 95% confidence interval, 1.7-11). Severe fetal growth restriction was strongly associated with increased risk for autism spectrum disorder+/intellectual disability- (odds ratio, 9.9; 95% confidence interval, 3.3-30), whereas peripartum maternal fever was uniquely associated with increased risk of autism spectrum disorder-/intellectual disability+ (odds ratio, 2.9; 95% confidence interval, 1.2-6.7).

CONCLUSION

Our study confirms that low gestational age is associated with increased risk for autism spectrum disorder irrespective of intellectual ability, whereas severe fetal growth restriction is strongly associated with autism spectrum disorder without intellectual disability. Maternal report of cervical-vaginal infection is associated with increased risk of autism spectrum disorder with intellectual disability, and peripartum maternal fever is associated with increased risk for intellectual disability without autism spectrum disorder.