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

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.

Indomethacin Prophylaxis in Preterm Infants: Changes over Time

OBJECTIVE

 Our objective was to examine changes in the use of indomethacin prophylaxis in the neonatal intensive care unit (NICU) between 2008 and 2018.

STUDY DESIGN

 The design of the study included cohort of 19,715 infants born between 220/7 and 266/7 weeks' gestation from 213 NICUs. A nonparametric trend test evaluated indomethacin prophylaxis and the percentage of sites using any prophylaxis over time. We evaluated the prevalence of indomethacin prophylaxis by the center and the correlation between indomethacin prophylaxis and severe intraventricular hemorrhage prevalence among 12 centers with the largest relative change in indomethacin prophylaxis prevalence.

RESULTS

 In total, 16% of infants received indomethacin prophylaxis. The use of indomethacin prophylaxis did not significantly decrease between 2008 and 2018 but it significantly decreased between 2014 and 2018 (p = 0.046). Among 74 centers with ≥10 infants included, 20% increased the use of indomethacin prophylaxis, while 57% decreased the use over the study period. Of the 12 centers with the largest relative change in indomethacin prophylaxis prevalence, 50% showed an inverse correlation between indomethacin prophylaxis prevalence and severe intraventricular hemorrhage, while 50% showed a positive correlation.

CONCLUSION

 Receipt of indomethacin prophylaxis remained similar until 2014, decreased from 2014 to 2018, and varied by the center.Key Points · The receipt of indomethacin prophylaxis decreased over time.. · Center change in the use of indomethacin prophylaxis does not correlate with the center prevalence of IVH.. · Variability in the use of indomethacin prophylaxis across centers persists..

Risk factors and epidemiology of spontaneous intestinal perforation among infants born at 22-24 weeks' gestational age

OBJECTIVE

To describe the epidemiology, risk factors, and timing of spontaneous intestinal perforation (SIP) among infants born at 22-24 weeks' gestational age (GA).

STUDY DESIGN

Observational cohort study among infants born at 22-24 weeks' GA in 446 neonatal intensive care units.

RESULTS

We identified 9712 infants, of whom 379 (3.9%) developed SIP. SIP incidence increased with decreasing GA (P < 0.001). Antenatal magnesium (odds ratio (OR) 1.42; 95% confidence interval (CI), 1.09-1.85), antenatal indomethacin (OR 1.40; 95% CI, 1.06-1.85), postnatal indomethacin (OR 1.61; 95% CI, 1.23-2.11), and postnatal hydrocortisone exposure (OR 2.02; 95% CI 1.50-2.73) were associated with SIP. Infants who lost 15-20% (OR 1.77; 95% CI, 1.28-2.44) or >20% (OR 2.04; 95% CI, 1.46-2.85) of birth weight had higher odds of SIP than infants with weight loss <10%.

CONCLUSIONS

Antenatal magnesium exposure, antenatal indomethacin exposure, postnatal hydrocortisone exposure, postnatal indomethacin exposure, and weight loss ≥15% were associated with SIP.

Prophylactic indomethacin, antenatal betamethasone, and the risk of intestinal perforation in infants <28 weeks' gestation

OBJECTIVE

To determine if intestinal perforations before 14 days (either spontaneous (SIP) or necrotizing enterocolitis-induced) are increased when infants who received antenatal betamethasone shortly before birth are treated with prophylactic indomethacin (PINDO).

STUDY DESIGN

Observational study of 475 infants <28 week's gestation assigned to either a PINDO-protocol (n = 231) or expectant management protocol (n = 244) during consecutive protocol epochs.

RESULTS

Intestinal perforations before 14 days occurred in 33/475 (7%). In unadjusted and adjusted models, we found no associations between PINDO-protocol and intestinal perforations. PINDO-protocol did not increase intestinal perforations or SIP-alone even when given to infants who received betamethasone <7 or <2 days before delivery. 213/231 (92%) PINDO-protocol infants actually received indomethacin. The results were unchanged when examined just in those who received indomethacin.

CONCLUSION

In our study, early intestinal perforations and SIP-alone were not increased when PINDO was used by protocol in infants who received antenatal betamethasone shortly before birth.

Antenatal Steroids, Prophylactic Indomethacin, and the Risk of Spontaneous Intestinal Perforation

OBJECTIVE

To estimate if the odds of spontaneous intestinal perforation (SIP) are increased when antenatal steroids (ANS) given close to delivery are combined with indomethacin on day 1 after birth (Indo-D1).

STUDY DESIGN

A retrospective cohort study using the Neonatal Research Network (NRN) database of inborn infants, gestational age 220-286 weeks or birth weight of 401-1000 g, born between January 1, 2016 and December 31, 2019, and surviving >12 hours. The primary outcome was SIP through 14 days. Time of last ANS dose prior to delivery was analyzed as a continuous variable (using 169 hours for durations >168 hours or no steroid exposure). Associations between ANS, Indo-D1, and SIP were obtained from a multilevel hierarchical generalized linear mixed model after covariate adjustment. This yielded aOR and 95% CI.

RESULTS

Of 6851 infants, 243 had SIP (3.5%). ANS exposure occurred in 6393 infants (93.3%) and IndoD1 was given to 1863 infants (27.2%). The time (median, IQR) from last dose of ANS to delivery was 32.5 hours (6-81) vs 37.1 hours (7-110) for infants with or without SIP, respectively (P = .10). Indo-D1 was given to 51.9 vs 26.3% of infants with SIP vs no SIP, respectively (P < .0001). Adjusted analysis indicated no interaction between time of last ANS dose and Indo-D1 for SIP (P = .7). Indo-D1 but not ANS was associated with increased odds of SIP (aOR: 1.73, 1.21-2.48, P = .003).

CONCLUSION

The odds of SIP were increased after receipt of Indo-D1. Exposure to ANS prior to Indo-D1 was not associated with an increase in SIP.

Single cell analysis via mass cytometry of spontaneous intestinal perforation reveals alterations in small intestinal innate and adaptive mucosal immunity

Introduction

Spontaneous intestinal perforation (SIP) is a poorly understood severe gastrointestinal complications of prematurity which is poorly understood. Extremely premature infants born prior to 28 weeks' gestation develop a localized perforation of the terminal ileum during the first week of life and therapy involves surgery and cessation of enteral feeds. Little is known regardj g the impact of mucosal immune dysfunction on disease pathogenesis.

Methods

We performed mass cytometry time of flight (CyTOF) of small intestinal mucosa of patients with SIP (Gestational age (GA) 24 - 27 weeks, n=8) compared to patients who had surgery for non-SIP conditions (neonatal (GA >36 weeks, n=5 ) and fetal intestine from elective terminations (GA 18-21 weeks, n=4). CyTOF analysis after stimulation of T cells with PMA/Ionomycin was also performed.

Results

We noted changes in innate and adaptive mucosal immunity in SIP. SIP mucosa had an expansion of ckit+ neutrophils, an influx of naïve CD4 and CD8 T cells and a reduction of effector memory T cells. SIP T cells were characterized by reduced CCR6 and CXCR3 expression and increased interferon gamma expression after stimulation.

Discussion

These findings suggest that previously unrecognized immune dysregulation is associated with SIP and should be explored in future studies.

Indomethacin Prophylaxis in Preterm Infants: Changes over Time

OBJECTIVE

 Our objective was to examine changes in the use of indomethacin prophylaxis in the neonatal intensive care unit (NICU) between 2008 and 2018.

STUDY DESIGN

 The design of the study included cohort of 19,715 infants born between 220/7 and 266/7 weeks' gestation from 213 NICUs. A nonparametric trend test evaluated indomethacin prophylaxis and the percentage of sites using any prophylaxis over time. We evaluated the prevalence of indomethacin prophylaxis by the center and the correlation between indomethacin prophylaxis and severe intraventricular hemorrhage prevalence among 12 centers with the largest relative change in indomethacin prophylaxis prevalence.

RESULTS

 In total, 16% of infants received indomethacin prophylaxis. The use of indomethacin prophylaxis did not significantly decrease between 2008 and 2018 but it significantly decreased between 2014 and 2018 (p = 0.046). Among 74 centers with ≥10 infants included, 20% increased the use of indomethacin prophylaxis, while 57% decreased the use over the study period. Of the 12 centers with the largest relative change in indomethacin prophylaxis prevalence, 50% showed an inverse correlation between indomethacin prophylaxis prevalence and severe intraventricular hemorrhage, while 50% showed a positive correlation.

CONCLUSION

 Receipt of indomethacin prophylaxis remained similar until 2014, decreased from 2014 to 2018, and varied by the center.Key Points · The receipt of indomethacin prophylaxis decreased over time.. · Center change in the use of indomethacin prophylaxis does not correlate with the center prevalence of IVH.. · Variability in the use of indomethacin prophylaxis across centers persists..

Association of Co-Exposure of Antenatal Steroid and Prophylactic Indomethacin with Spontaneous Intestinal Perforation

OBJECTIVE

To evaluate the association of a combined exposure to antenatal steroids and prophylactic indomethacin with the outcome of spontaneous intestinal perforation (SIP) among neonates born at <26 weeks of gestation or <750 g birth weight.

STUDY DESIGN

We conducted a retrospective study of preterm infants admitted to Canadian Neonatal Network units between 2010 and 2018. Infants were classified into 2 groups based on receipt of antenatal steroids; the latter subgrouped as recent (≤7 days before birth) or latent (>7 days before birth) exposures. The co-exposure was prophylactic indomethacin. The primary outcome was SIP. Multivariable logistic regression analysis was used to calculate aORs.

RESULTS

Among 4720 eligible infants, 4121 (87%) received antenatal steroids and 1045 (22.1%) received prophylactic indomethacin. Among infants exposed to antenatal steroids, those who received prophylactic indomethacin had higher odds of SIP (aOR 1.61, 95% CI 1.14-2.28) compared with no prophylactic indomethacin. Subgroup analyses revealed recent antenatal steroids exposure with prophylactic indomethacin had higher odds of SIP (aOR 1.67, 95% CI 1.15-2.43), but latent antenatal steroids exposure with prophylactic indomethacin did not (aOR 1.24, 95% CI 0.48-3.21), compared with the respective groups with no prophylactic indomethacin. Among those not exposed to antenatal steroids, mortality was lower among those who received prophylactic indomethacin (aOR 0.45, 95% CI 0.28-0.73) compared with no prophylactic indomethacin.

CONCLUSIONS

In preterm neonates of <26 weeks of gestation or birth weight <750 g, co-exposure of antenatal steroids and prophylactic indomethacin was associated with SIP, especially if antenatal steroids was received within 7 days before birth. Among those unexposed to antenatal steroids, prophylactic indomethacin was associated with lower odds of mortality.

Association of antenatal steroids with neonatal mortality and morbidity in preterm infants born to mothers with diabetes mellitus and hypertension

BACKGROUND

Randomized trials of antenatal steroids (ANS) included women at 24-33 weeks gestational age (GA); however, few women had preeclampsia and women with diabetes mellitus (DM) were excluded.

METHODS

Cohort study including preterm births at 230/7-286/7 weeks GA before (Epoch-1) and after (Epoch-2) expansion of ANS administration to women with DM and hypertensive disorders (HTN). We compared Group-A (neither DM nor HTN) and Group-B (DM and/or HTN).

RESULTS

Among 747 neonates the adjusted odds ratio (aOR) for surfactant administration, in-hospital mortality, severe intraventricular hemorrhage (IVH) and death or severe IVH were lower in ANS-exposed neonates than unexposed neonates. In Group-B, ANS administration was independently associated with less severe IVH and less death or severe IVH, but not less surfactant use or mortality.

CONCLUSIONS

Increased ANS administration in women with DM and/or HTN was independently associated with less severe IVH and less death or severe IVH but without decrease in surfactant administration.