Early postnatal nutrition and renal consequences in preterm infants.

Perinatal nutritional factors may lead to decreased nephron endowment, decreased kidney function, and long-term development of chronic kidney disease and non-communicable diseases. At the same time, optimal postnatal nutrition and catch-up growth are associated with better neurodevelopmental outcomes in preterm infants. Therefore, nutritional management of preterm infants is a major challenge for neonatologists. In this context, the Section of Nutrition, Gastroenterology and Metabolism reviewed the current knowledge on nutritional issues related to kidney function. This narrative review discusses the clinical impact of early postnatal nutrition on long-term kidney function. In preterm infants, data are largely lacking to determine the extent to which early nutrition contributes to nephrogenesis and nephron endowment. However, some nutritional principles may help clinicians better protect the developing kidney in preterm infants. IMPACT: Clinical data show that preterm infants are an emerging population at high risk for chronic kidney disease. Both undernutrition and overnutrition can alter long-term kidney function. In preterm infants, data are largely lacking to determine the extent to which early postnatal nutrition contributes to nephrogenesis, nephron endowment and increased risk for chronic kidney disease. Some nutritional principles may help clinicians better protect the developing kidney in preterm infants: avoiding extrauterine growth restriction; providing adequate protein and caloric intakes; limiting exposure to high and prolonged hyperglycaemia; avoiding micronutrient deficiencies and maintaining acid-base and electrolyte balance.

Post-obstructive diuresis after posterior urethral valve treatment in neonates: a retrospective cohort study.

BACKGROUND: The management of posterior urethral valve (PUV) in neonates requires close monitoring in the intensive care unit because of the risk of post-obstructive diuresis (POD). Our aim was to describe the incidence and factors associated with POD in newborns treated for PUV. METHODS: Retrospective analysis of the medical records of all neonates who underwent surgical intervention for PUV in our neonatal intensive care unit between January 2014 and April 2021. RESULTS: Of the 40 patients included, 15 (37.5%) had POD defined by urine output > 6 ml.kg-1.h-1 during the first 24 h following urinary tract obstruction relief. At prenatal ultrasound examinations, oligohydramnios was more common in the group with POD than in the group without (53.3% vs. 8%, p = 0.002). Preterm birth was more frequent in neonates with POD (66.7% vs. 8%; p < 0.001). Median serum creatinine (212 [137-246] vs. 95 [77-125] µmol.l-1; p < 0.001) and urea (8.5 [5.2-12.2] vs. 4.1 [3.5-4.7] mmol.l-1; p < 0.001) concentrations on the day of obstruction relief were significantly higher in the group with POD than in the group without. After adjustment for prematurity, logistic regression models confirmed correlation between the occurrence of POD and the severity of the consequences of urethral obstruction (i.e., oligohydramnios and serum creatinine levels; ß = 2.90 [0.88; 5.36], p = 0.013 and ß = 0.014 [0.003; 0.031], p = 0.034, respectively). CONCLUSIONS: In neonates, POD is common after the relief of PUV-related obstruction. Our findings may help to identify patients at highest risk. A higher resolution version of the Graphical abstract is available as Supplementary information.

Renal function after ductus arteriosus transcatheter closure with or without angiography in very preterm infants.

AIM: Transcatheter closure of the patent ductus arteriosus (TCPDA) is increasingly used in preterm infants as an alternative to surgical ligation. However, clinically ill preterm infants are at risk of contrast nephropathy due to the angiography contrast agents used during the procedure. METHODS: We performed a single-centre before-and-after comparative study in VLBW infants to compare the kinetics of serum creatinine during the first 4 days after TCPDA with or without angiography. RESULTS: 69 patients were included and divided into two groups: TCPDA with (contrast+; n = 37) and without (contrast-, n = 32) use of contrast agent. The median dose [range] of contrast agent was 1.0 mL/kg [0.6-2.4 mL/kg]. The change in serum creatinine level between day 2 to 4 after TCPCA and baseline decreased in the contrast- group (-17% [-46%; 18%]), while it increased in the contrast+ group (7% [-24%; 202%] p = 0.002). Comparison of blood urea levels between groups showed similar significant differences. The change in serum creatinine between day 2 to 4 and baseline was significantly correlated with the dose of contrast agent (r2 = 0.682; p < 0.001). CONCLUSION: The use of contrast agents during TCPDA can potentially harm the renal function of very preterm infants. Therefore, we advise minimising or avoiding the use of contrast agents.

Nutrition of the preterm infant with persistent ductus arteriosus: existing evidence and practical implications.

The persistence of a patent ductus arteriosus (PDA) is a common condition in preterm infants with a prevalence inversely proportional to gestational age. PDA is associated with mild-to-severe gastrointestinal complications such as feeding intolerance, gastrointestinal perforation, and necrotizing enterocolitis, which represent a major challenge for the nutritional management in preterm infants. In this context, the Section on Nutrition, Gastroenterology and Metabolism and the Circulation Section of the European Society for Pediatric Research have joined forces to review the current knowledge on nutritional issues related to PDA in preterm infants. The aim of the narrative review is to discuss the clinical implications for nutritional practice. Because there is little literature on postnatal nutrition and PDA in preterm infants, further research with well-designed studies on this topic is urgently needed. Guidelines should also be developed to clearly define the implementation and course of enteral nutrition and the target nutritional intake before, during, and after pharmacologic or surgical treatment of PDA, when indicated. IMPACT: Persistent ductus arteriosus (PDA) is associated with gastrointestinal complications such as feeding intolerance, gastrointestinal perforation, and necrotizing enterocolitis, which pose a major challenge to the nutritional management of preterm infants. In PDA infants, fluid restriction may lead to inadequate nutrient intake, which may negatively affect postnatal growth and long-term health. The presence of PDA does not appear to significantly affect mesenteric blood flow and splanchnic oxygenation after enteral feedings. Initiation or maintenance of enteral nutrition can be recommended in infants with PDA.

Enteral Nutrition in Preterm Infants (2022): A Position Paper From the ESPGHAN Committee on Nutrition and Invited Experts.

OBJECTIVES: To review the current literature and develop consensus conclusions and recommendations on nutrient intakes and nutritional practice in preterm infants with birthweight <1800 g. METHODS: The European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee of Nutrition (CoN) led a process that included CoN members and invited experts. Invited experts with specific expertise were chosen to represent as broad a geographical spread as possible. A list of topics was developed, and individual leads were assigned to topics along with other members, who reviewed the current literature. A single face-to-face meeting was held in February 2020. Provisional conclusions and recommendations were developed between 2020 and 2021, and these were voted on electronically by all members of the working group between 2021 and 2022. Where >90% consensus was not achieved, online discussion meetings were held, along with further voting until agreement was reached. RESULTS: In general, there is a lack of strong evidence for most nutrients and topics. The summary paper is supported by additional supplementary digital content that provide a fuller explanation of the literature and relevant physiology: introduction and overview; human milk reference data; intakes of water, protein, energy, lipid, carbohydrate, electrolytes, minerals, trace elements, water soluble vitamins, and fat soluble vitamins; feeding mode including mineral enteral feeding, feed advancement, management of gastric residuals, gastric tube placement and bolus or continuous feeding; growth; breastmilk buccal colostrum, donor human milk, and risks of cytomegalovirus infection; hydrolyzed protein and osmolality; supplemental bionutrients; and use of breastmilk fortifier. CONCLUSIONS: We provide updated ESPGHAN CoN consensus-based conclusions and recommendations on nutrient intakes and nutritional management for preterm infants.

Urinary protein to creatinine ratio during the first month of life in very preterm infants-a prospective cohort study (PROTIPREMA).

BACKGROUND: Preterm infants have physiological proteinuria and values of urine protein to creatinine ratio (UPr/Cr) are higher compared to full-term infants during the first week of life. Few investigations explored the changes of proteinuria in very preterm infants (VPI, ≤ 31 weeks of gestation) older than a week, and it is unclear whether high and persistent proteinuria is associated with kidney injury in this population. This study aimed to (1) observe the changes of UPr/Cr during the first month of life in VPI and (2) describe clinical and biological variables associated with the changes of UPr/Cr. METHODS: Spot urine samples for UPr/Cr were collected on the first day of life (DOL1) and then on DOL2-3, DOL5-6, second week of life (WOL2), WOL3, and WOL4 in VPI cared for in a third-level NICU. We tested the relationship of UPr/Cr with perinatal variables and diseases. RESULTS: A total of 1140 urine samples were obtained for 190 infants. UPr/Cr values (mg/mmol) (median with interquartile) at DOL1, DOL2, DOL3, WOL2, WOL3, and WOL4 were, respectively, 191 (114-399), 226 (152-319), 225 (156-350), 282 (200-488), 308 (188-576), and 325 (175-664). At the multivariate analysis, lower gestational age (GA) and increasing postnatal age were the only variables significantly associated with higher UPr/Cr values (p < 0.001). There was wide intra- and interindividual variability in UPr/Cr, especially in infants with higher GA and clinical stability. CONCLUSIONS: In VPI, UPr/Cr is higher at lower GA and increases with advancing postnatal age. High persistent proteinuria is not associated with clinical and biological variables reflecting kidney injury during the first month of life. A higher resolution version of the Graphical abstract is available as Supplementary information.

Research priorities in pediatric parenteral nutrition: a consensus and perspective from ESPGHAN/ESPEN/ESPR/CSPEN.

Parenteral nutrition is used to treat children that cannot be fully fed by the enteral route. While the revised ESPGHAN/ESPEN/ESPR/CSPEN pediatric parenteral nutrition guidelines provide clear guidance on the use of parenteral nutrition in neonates, infants, and children based on current available evidence, they have helped to crystallize areas where research is lacking or more studies are needed in order to refine recommendations. This paper collates and discusses the research gaps identified by the authors of each section of the guidelines and considers each nutrient or group of nutrients in turn, together with aspects around delivery and organization. The 99 research priorities identified were then ranked in order of importance by clinicians and researchers working in the field using a survey methodology. The highest ranked priority was the need to understand the relationship between total energy intake, rapid catch-up growth, later metabolic function, and neurocognitive outcomes. Research into the optimal intakes of macronutrients needed in order to achieve optimal outcomes also featured prominently. Identifying research priorities in PN should enable research to be focussed on addressing key issues. Multicentre trials, better definition of exposure and outcome variables, and long-term metabolic and developmental follow-up will be key to achieving this. IMPACT: The recent ESPGHAN/ESPEN/ESPR/CSPEN guidelines for pediatric parenteral nutrition provided updated guidance for providing parenteral nutrition to infants and children, including recommendations for practice. However, in several areas there was a lack of evidence to guide practice, or research questions that remained unanswered. This paper summarizes the key priorities for research in pediatric parenteral nutrition, and ranks them in order of importance according to expert opinion.

When the progresses in neonatology lead to severe congenital nephron deficit: is there a pilot in the NICU?

Advances in the care of neonates to the extreme limits of viability have increased the risk of severe comorbidities in surviving preemies. The respiratory and the neurodevelopmental consequences of premature birth and/or intra-uterine growth retardation have been well described. Because of the usual clinical silence of the kidney, the long-term renal consequences of low birth weight have not been as well studied. A case report illustrates the risk factors associated with low birth weight and prematurity and discusses the pathogenesis of the late consequences of the congenital nephron deficit associated with a low birth weight. Practical recommendations are given for a tight follow-up of these newly born preemies.

Use of diuretics in the neonatal period.

The use of diuretics is extremely frequent in sick neonates, the more so in very premature newborn infants. The use of diuretics in patients whose kidney function is immature necessitates a thorough knowledge of renal developmental physiology and pathophysiology. This review presents the basic aspects of body fluid homeostasis in the neonate, discusses the development of kidney function, and describes the mechanisms involved in electrolyte and water reabsorption along the nephron. Diuretics are then classified according to the site of their action on sodium reabsorption. The use of diuretics in sodium-retaining states, in oliguric states, in electrolyte disorders, and in arterial hypertension, as well as in a few specific disorders, is presented. Common and specific adverse effects are discussed. Recommended dosages for the main diuretics used in the neonatal period are given. New developments in diuretic therapy are briefly mentioned.

Maturation of glomerular filtration rate in neonates and infants: an overview.

Glomerular filtration rate (GFR) increases progressively throughout fetal life, matures rapidly after birth according to gestational and post-menstrual age, and reaches adult values by 1-year post-natal age. GFR is considered the best marker of kidney function, and in clinical practice, estimated GFR is useful to anticipate complications, establish prognosis, and facilitate treatment decisions. This review article summarizes the maturation of glomerular filtration and the factors and conditions that modulate and impair developing glomerular filtration, and discusses the techniques available to assess GFR in neonates and infants. We focused on simple, reliable, easily available, and cheap techniques to estimate GFR, which may provide valuable information on the renal aspects of the clinical care of this group of patients.

Drug exposure for PDA closure in France: a prospective, cohort-based, analysis.

PURPOSE: To describe the exposure to drugs used for the treatment of patent ductus arteriosus (PDA) in a large cohort of preterm infants born before 32 weeks of gestation. METHODS: A prospective observational cohort analysis was conducted during 2 years in 28 French level 3 NICU using the same computerized order-entry system. The main outcome was "a medically treated PDA," defined as exposure to ibuprofen, indomethacin, or paracetamol prescribed with the indication of PDA closure. Secondary outcomes were as follows: time of the first treatment administration; total exposure to furosemide during hospitalization; and rate of PDA refractory to pharmacological closure. RESULTS: The study cohort consisted of 2614 infants. Among them, 474 (18.1%) received a medical treatment for PDA, with a mean postnatal age at treatment of 4.3 ± 6.6 days. The drug used as a first-line treatment was ibuprofen in 89.5% and paracetamol in 10.5%. One hundred and ninety-five infants (7.4%) had a PDA refractory to pharmacological closure. At the multivariate analysis, factors associated with PDA refractory to pharmacological closure (OR; 95% CI) were as follows: gestational age (GA) (0.81; 0.72-0.90), paracetamol as the first-line treatment (0.32; 0.15-0.68), and pharmacological treatment before 48 h of life (0.63; 0.43-0.94). 24.6% of the study cohort was exposed to furosemide (cumulative dose 6.5 ± 12.6 mg/kg). Variables significantly associated with higher cumulative doses of furosemide were lower GA and ibuprofen treatment (both p < 0.0001). CONCLUSION: Drug utilization patterns in infants with PDA vary among centers. Pharmacoepidemiology studies can provide new information on factors associated with PDA refractory to medical treatment.

Renal aspects of metabolic acid-base disorders in neonates.

Acid-base homeostasis is one of the most tightly regulated systems in the body. Maintaining the acid-base balance is particularly challenging for preterm infants and growing neonates. The kidney, which represents the crucial ultimate line of defense against disturbances of acid-base balance, undergoes a complex maturation process during the transition from a fetal to an extra-uterine environment. This review article summarizes the physiology of acid-base regulation by the immature human kidney and discusses disorders of acid-base balance, such as metabolic acidosis, respiratory acidosis, metabolic alkalosis, and respiratory alkalosis. In conditions of metabolic acidosis, the serum anion gap and the urinary anion gap can be useful tools to define the nature of the acidosis. Metabolic acidosis can reflect a decrease in glomerular filtration rate, or be the consequence of selective disorders of proximal or distal tubular function. Most tubulopathies associated with metabolic acidosis observed in neonates are primary, hereditary, isolated tubulopathies. Proximal renal tubular acidosis is characterized by bicarbonate wasting, while the distal types of renal tubular acidosis are secondary to distal acidification defects. All tubulopathies are associated with hypokalemia, with the exception of type 4 hyperkalemic distal renal tubular acidosis. The transporter defects in the various acid-base tubulopathies are now well defined. Treatment of the acidosis varies according to the site and mechanism of the defect. Chronic renal tubular acidosis or alkalosis severely impair growth and calcium metabolism. Early rational therapeutic intervention can prevent some of the consequences of the disorders and improves the prognosis.

Validation of the 34-week gestation as definition of late onset preeclampsia: Testing different cutoffs from 30 to 37 weeks on a population-based cohort of 1700 preeclamptics.

INTRODUCTION: Early onset preeclampsia (EOP) and late onset preeclampsia (LOP) have been differentiated with a cut-point of ≤34 weeks. This classical definition has never been examined with respect to maternal characteristics by different gestational age cut-points. We examined maternal characteristics in a population-based cohort of 1736 preeclamptic deliveries at different gestational age cut-points from 30 to 37 weeks (CO30 to CO37). MATERIAL AND METHODS: Eighteen-year observational population-based historical cohort study (2001-2018). All consecutive births delivered at the Centre Hospitalier Universitaire Hospitalier Sud Reunion's maternity. Standardized epidemiological perinatal database. RESULTS: The incidence of EOP was lower in adolescents (1.8% vs 3.5%, odds ratio [OR] 0.50, P = .17). Conversely, the odds of LOP was increased for women over 35, beginning at C030 (OR 1.13, P = .02) and this effect (OR = 1.2) was still detectable at C037 (P = .06). Among primigravid women, the incidence of EOP was lower than LOP (OR ranging from 0.71 to 0.82 for different CO). Conversely, the incidence of LOP was higher (adjusted OR about 2.7 [CO30-CO34] with a rise to 3.3 at CO37 (P < .001). Women with EOP had a lower body mass index (BMI) as compared with LOP at CO34 and CO37. The adjusted OR (per 5 kg/m2 increment) declined from 1.06 to 1.03 from CO30 to C037 in EOP women. Conversely, for LOP, the adjusted odds ratio (aOR) increased from 1.04 to 1.06 from CO30 to CO37 (P < .001). Gestational diabetes mellitus was not associated with LOP at any cut-off (aOR 1.07, NS) but was protective against EOP from CO30 to CO34 (aOR 0.42, 0.61 and 0.73, respectively, P < .001). This protective effect disappeared at CO37. Chronic hypertension and history of preeclampsia were both EOP and LOP risks but with a much stronger effect for EOP (chronic hypertension: aOR 6.0-6.5, history of preeclampsia: aOR 12-17). CONCLUSIONS: The 34th week of gestation appears to provide a reasonable cut-point to differentiate between EOP and LOP. Additional research is needed to better describe the possible differences in the pathophysiology of these different phenotypes.

Gestational age and 1-year hospital admission or mortality: a nation-wide population-based study.

BACKGROUND: Describe the 1-year hospitalization and in-hospital mortality rates, in infants born after 31 weeks of gestational age (GA). METHODS: This nation-wide population-based study used the French medico-administrative database to assess the following outcomes in singleton live-born infants (32-43 weeks) without congenital anomalies (year 2011): neonatal hospitalization (day of life 1 - 28), post-neonatal hospitalization (day of life 29 - 365), and 1-year in-hospital mortality rates. Marginal models and negative binomial regressions were used. RESULTS: The study included 696,698 live-born babies. The neonatal hospitalization rate was 9.8%. Up to 40 weeks, the lower the GA, the higher the hospitalization rate and the greater the likelihood of requiring the highest level of neonatal care (both p < 0.001). The relative risk adjusted for sex and pregnancy-related diseases (aRR) reached 21.1 (95% confidence interval [CI]: 19.2-23.3) at 32 weeks. The post-neonatal hospitalization rate was 12.1%. The raw rates for post-neonatal hospitalization fell significantly from 32 - 40 and increased at 43 weeks and this persisted after adjustment (aRR = 3.6 [95% CI: 3.3-3.9] at 32 and 1.5 [95% CI: 1.1-1.9] at 43 compared to 40 weeks). The main causes of post-neonatal hospitalization were bronchiolitis (17.2%), gastroenteritis (10.4%) ENT diseases (5.4%) and accidents (6.2%). The in-hospital mortality rate was 0.85‰, with a significant decrease (p < 0.001) according to GA at birth (aRR = 3.8 [95% CI: 2.4-5.8] at 32 and 6.6 [95% CI: 2.1-20.9] at 43, compared to 40 weeks. CONCLUSION: There's a continuous change in outcome in hospitalized infants born above 31 weeks. Birth at 40 weeks gestation is associated with the lowest 1-year morbidity and mortality.

Nutrition practice, compliance to guidelines and postnatal growth in moderately premature babies: the NUTRIQUAL French survey.

BACKGROUND: The nutritional care provided to moderately premature babies is poorly studied. For a large cohort of such babies, we aimed to describe: nutrition practice intentions, comparison of the intended with the actual practice, compliance of actual practice to current nutrition guidelines, and postnatal growth. METHODS: A questionnaire was sent out to 29 neonatal intensive care units in France, in order to address practice intentions. In the same units, retrospective patient's data were collected to assess actual practice, compliance to nutrition guidelines and infant postnatal growth. The cumulative nutritional deficit during the two first weeks of life was calculated and variables associated with ΔZ-score for weight at 36 weeks postconceptional age/discharge (ΔZ-score(w) 36PCA/DC) were analysed by multivariate linear regression. RESULTS: 276 infants born 30 to 33 weeks of gestation were studied. Among them, 76% received parenteral nutrition on central venous line after birth. On day of life 1 (DOL1), 93% of infants had parenteral amino acids (AA), at an intake ≥ 1.5 g/kg in 27% of cases. Lipids were started at ≤ DOL2 in 47% of infants. There was a divergence between the intended and the actual practice for both AA and lipids intake. The AA and energy cumulative deficit (DOL1 to DOL14) were respectively 10.9 ± 8.3 g/kg and 483 ± 181 kcal/kg. Weight Z-score (mean ± SD) significantly decreased from birth (-0.17 ± 0.88) to 36 weeks PCA/DC (-1.00 ± 0.82) (p < 0.0001), and the extra-uterine growth retardation (EUGR) rate at 36 weeks PCA/DC was 24.2%. Independent variables associated with ΔZ-score(w) 36PCA/DC were AA cumulative intake and DOL of full enteral feeding. CONCLUSIONS: Nutrition intake was not in compliance with recommendations, and the rate of EUGR was considerable in this cohort. Efforts are needed to improve adherence to nutrition guidelines and growth outcome of moderately preterm infants.

Nutritional Strategies for Preterm Neonates and Preterm Neonates Undergoing Surgery: New Insights for Practice and Wrong Beliefs to Uproot.

The nutrition of preterm infants remains contaminated by wrong beliefs that reflect inexactitudes and perpetuate old practices. In this narrative review, we report current evidence in preterm neonates and in preterm neonates undergoing surgery. Convictions that necrotizing enterocolitis is reduced by the delay in introducing enteral feeding, a slow advancement in enteral feeds, and the systematic control of residual gastric volumes, should be abandoned. On the contrary, these practices prolong the time to reach full enteral feeding. The length of parenteral nutrition should be as short as possible to reduce the infectious risk. Intrauterine growth restriction, hemodynamic and respiratory instability, and patent ductus arteriosus should be considered in advancing enteral feeds, but they must not translate into prolonged fasting, which can be equally dangerous. Clinicians should also keep in mind the risk of refeeding syndrome in case of high amino acid intake and inadequate electrolyte supply, closely monitoring them. Conversely, when preterm infants undergo surgery, nutritional strategies are still based on retrospective studies and opinions rather than on randomized controlled trials. Finally, this review also highlights how the use of adequately fortified human milk is strongly recommended, as it offers unique benefits for immune and gastrointestinal health and neurodevelopmental outcomes.

Diuretic drug utilization in neonates: a French prescription database analysis.

Background: The use of diuretics is extremely common in infants cared for in neonatal wards, despite the lack of proven efficacy for many conditions. The main objective of this study was to assess the rate of diuretics exposure in a multicenter French cohort. The secondary objectives were to describe the evolution of this exposure over time, the indications, the prescription practices, and the exposure rates among centers. Methods: An observational study was conducted in 40 Level 3 French neonatal intensive care units using the same computerized order-entry system. Neonates hospitalized between January 2017 to December 2021 with a corrected age between 24 and 44 weeks of gestation at admission were eligible. Results: A total of 86,032 patients were included. The exposure rate was 8.5%, more specifically 29.4% for children born at < 32 weeks of gestation and 3.7% for neonates born at term. There was no significant variation over the study period, but the exposure ranged from 2.4% to 26.5% depending on the center. The main drugs prescribed were furosemide, spironolactone and dopamine with a diuretic purpose. The main indications were "fluid retention," and to a lesser extent "bronchopulmonary dysplasia" and "post-transfusion." For furosemide, the first exposure occurred in mean at 16.5 (±17.8) days of life, mean duration of exposure was 6.2 (±9.5) days, and the cumulative dose was in mean 10.7 (23.9) mg/kg. Conclusion: Diuretic prescription practices vary between centers. The administration of these drugs is often non-evidence based, doses and duration of treatment easily exceed toxic thresholds.