The long-term renal and cardiovascular consequences of prematurity

Association of delayed cord clamping with acute kidney injury and two-year kidney outcomes in extremely premature neonates: a secondary analysis of the Preterm Erythropoietin Neuroprotection Trial (PENUT)

Background : Delayed cord clamping (DCC) occurs in most preterm births. Objective : Evaluate the association of DCC with acute kidney injury (AKI) and two-year kidney outcomes. Methods : Secondary analysis of the Preterm Erythropoietin Neuroprotection Trial of neonates born 24 0/7 to 27 6/7 weeks' gestation. AKI and two year kidney outcomes were compared in neonates with DCC (≥30 seconds after delivery) to those with early cord clamping (ECC) (<30 seconds after delivery). Results : The incidence and severity of AKI did not differ between the DCC and ECC groups (aOR 1.17 [95%CI 0.76-1.80]). At two years corrected age, DCC was associated with a 4.5-fold times increased adjusted odds of eGFR <90 mL/min/1.73m 2 . No significant associations were noted between DCC and albuminuria or elevated BP. Conclusions : DCC was not associated with decreased neonatal AKI, but was associated with higher adjusted odds of eGFR <90 mL/min/1.73m 2 at two years.

Time to Reach Full Enteral Feeding and Its Predictors among Very Low Birth Weight Neonates Admitted in the Neonatal Intensive Care Unit: A Follow-Up Cohort Study

Background

Feeding is crucial for very low birth weight neonates to grow and develop properly. This study aims to determine the time to achieve full enteral feeding and predictors among neonates admitted at Felege Hiwot Comprehensive Specialized Hospital.

Methods

An institutional retrospective follow-up study design was conducted among 332 very low birth weight neonates from July 1, 2018, to June 30, 2021. Samples were selected through a computer-generated simple random sampling method, and the data were entered into Epi data version 4.6 and then exported to STATA version 16 for analysis. Kaplan-Meier with the log-rank test was used to test for the presence of difference in survival among predictor variables. Model goodness of fit and assumptions were checked by the Cox-Snell residual and the global test, respectively. Variables with p value <0.25 in the bi-variable analysis were fitted to the multivariable Cox-proportional hazard model. Finally, the adjusted hazard ratio (AHR) with 95% CI was computed, and variables with a p value less than 0.05 in the multivariable Cox regression analysis were considered significant predictors of time to reach full enteral feeding.

Results

A total of 332 neonates were followed for 2,132 person days of risk time and 167 (50.3%) of very low birth weight neonates started full enteral feeding. The overall incidence rate of full enteral feeding was 7.8 per 100 person day observations. The median survival time was 7 days. Very low birth weight neonates delivered from pregnancy-induced hypertension-free mothers (AHR: 2.1; 95% CI: 1.12, 3.94), gestational age of ≥33 weeks (AHR: 5,; 95% CI: 2.29, 11.13), kangaroo mother care initiated (AHR: 1.4; 95% CI: 1.01, 2.00), avoiding prefeed residual aspiration (AHR: 1.42; 95% CI: 1.002-2.03), and early enteral feeding (AHR: 1.5; 95% CI: 1.03, 2.35) were significant predictors of full enteral feeding.

Conclusions

According to this study, the time to achieve full enteral feeding was relatively short. Therefore, healthcare professionals should emphasize achieving full enteral feeding and address hindering factors to save the lives of VLBW neonates.

Time to full enteral feeding and its predictors among very low birth weight (VLBW) neonates admitted to the neonatal intensive care units (NICU) in comprehensive specialized hospitals in Northwest Ethiopia

BACKGROUND

Time to full enteral feeding is the time when neonates start to receive all of their prescribed nutrition as milk feeds. Delayed to achieve full enteral feeding had resulted in short- and long-term physical and neurological sequelae. However, there are limited studies to assess the time to full enteral feeding and its predictors among very low birth-weight neonates in Ethiopia. Therefore, this study aimed to assess the time to full enteral feeding and its predictors among very low birth-weight neonates admitted to comprehensive specialized hospitals in Northwest Ethiopia.

METHODS

A multi-center institutional-based retrospective follow-up study was conducted among 409 VLBW neonates from March 1, 2019 to February 30, 2023. A simple random sampling method was used to select study participants. Data were entered into EpiData version 4.2 and then exported into STATA version 16 for analysis. The Kaplan-Meier survival curve together with the log-rank test was fitted to test for the presence of differences among groups. Proportional hazard assumptions were checked using a global test. Variables having a p- value < 0.25 in the bivariable Cox-proportional hazard model were candidates for multivariable analysis. An adjusted Hazard Ratio (AHR) with 95% Confidence Intervals (CI) was computed to report the strength of association, and variables having a P-value < 0.05 at the 95% confidence interval were considered statistically significant predictor variables.

RESULT

The median time to full enteral feeding was 10 (CI: 10-11) days. Very Low Birth-Weight (VLBW) neonates who received a formula feeding (AHR: 0.71, 95% CI: 0.53, 0.96), gestational age of 32-37 weeks (AHR: 1.66, 95% CI: 1.23, 2.23), without Necrotizing Enterocolitis (NEC) (AHR: 2.16, 95% CI: 1.65, 2.84), and single birth outcome (AHR: 1.42, 95% CI: 1.07, 1.88) were statistically significant variables with time to full enteral feeding.

CONCLUSION AND RECOMMENDATIONS

This study found that the median time to full enteral feeding was high. Type of feeding, Necrotizing Enterocolitis (NEC), Gestational Age (GA) at birth, and birth outcome were predictor variables. Special attention and follow-up are needed for those VLBW neonates with NEC, had a GA of less than 32 weeks, and had multiple birth outcomes.

The Association Between Pre-Pregnancy and First-Trimester Hair Cortisol and Preterm Birth: A Causal Inference Model

Background Adverse life events and chronic psychological distress before and during pregnancy have frequently been associated with preterm birth (PTB) but the biological underpinnings remain unclear. We investigated the association between corticosteroid levels in pre-pregnancy and first-trimester hair and the risk of PTB. Methods We followed 1,808 pregnant women from a prospective pre-birth cohort study in Lima, Perú. Hair samples were taken at the end of the first pregnancy trimester. The two most proximal 3cm segments to the scalp (representing pre-pregnancy and first-trimester) were analyzed to obtain hair cortisol and cortisone concentrations (HCC and HCNC). PTB was defined as birth < 37 completed gestational weeks. We constructed four generalized propensity scores for pre-pregnancy and first-trimester HCC and HCNC to create corresponding inverse probability weights before fitting marginal structural models for estimating the effect of HCC and HCNC on PTB risk. Results Pre-pregnancy Log HCC was not independently associated with PTB risk (RR = 0.97; 95%CI: 0.79, 1.19). In contrast, one SD increase from the mean first-trimester Log HCC was independently associated with a 37% (95%CI: 1.11, 1.69) increased risk of PTB. Although imprecise, pre-pregnancy Log HCNC was negatively associated with PTB risk (RR = 0.84; 95%CI: 0.58, 1.20), whereas the association between first-trimester Log HCNC and PTB risk was positive (RR = 1.20; 95%CI: 0.87, 1.65). Conclusions Our findings show that chronic corticosteroid levels in early pregnancy are causally linked to PTB risk in pregnant Peruvian women. This finding contributes to understanding the biological underpinnings of PTB better to enhance PTB prevention.

Maternal Hypertension Disorders and Neonatal Acute Kidney Injury: Results from the AWAKEN Study

OBJECTIVE

This study aimed to examine the association between maternal hypertension (HTN) exposure and neonatal acute kidney injury (AKI).

STUDY DESIGN

Retrospective cohort study of 2,162 neonates admitted to 24 neonatal intensive care units (NICUs). Neonates were classified into the following exposure groups: any maternal HTN, chronic maternal HTN, preeclampsia/eclampsia, both, or neither. Demographics, clinical characteristics, and AKI status were compared using Chi-square and analysis of variance. General estimating logistic regression was used to estimate adjusted odds ratios and included a stratified analysis for site of delivery.

RESULT

Neonates exposed to any maternal HTN disorder had a tendency toward less overall and early AKI. When stratified by inborn versus outborn, exposure to both maternal HTN disorders was associated with a significantly reduced odds of early AKI only in the inborn neonates.

CONCLUSION

Exposure to maternal HTN, especially preeclampsia/eclampsia superimposed on chronic HTN, was associated with less likelihood of early AKI in the inborn group.

KEY POINTS

· Maternal HTN is associated with less neonatal AKI.. · Maternal HTN category is variably associated with AKI.. · Inborn status is an important contributor to this association..

Impact of preterm birth on kidney health and development

Preterm birth, defined as birth before the gestational age of 37 weeks, affects 11% of the newborns worldwide. While extensive research has focused on the immediate complications associated with prematurity, emerging evidence suggests a link between prematurity and the development of kidney disease later in life. It has been demonstrated that the normal course of kidney development is interrupted in infants born prematurely, causing an overall decrease in functional nephrons. Yet, the pathogenesis leading to the alterations in kidney development and the subsequent pathophysiological consequences causing kidney disease on the long-term are incompletely understood. In the present review, we discuss the current knowledge on nephrogenesis and how this process is affected in prematurity. We further discuss the epidemiological evidence and experimental data demonstrating the increased risk of kidney disease in these individuals and highlight important knowledge gaps. Importantly, understanding the intricate interplay between prematurity, abnormal kidney development, and the long-term risk of kidney disease is crucial for implementing effective preventive and therapeutic strategies.

A retrospective analysis of the safety of tacrolimus use and its optimal cut-off concentration during pregnancy in women with systemic lupus erythematosus: study from two Japanese tertiary referral centers

BACKGROUND

Tacrolimus is one of the major treatment options for systemic lupus erythematosus (SLE) and is considered to be a pregnancy-compatible medication. Since little is known about tacrolimus safety during pregnancy complicated by SLE, this study was designed.

METHODS

We included SLE pregnant patients who were followed up at two Japanese tertiary referral centers. We performed multivariate logistic regression analysis to assess each adverse pregnancy outcome (APO) risk. Moreover, we assessed the influence of tacrolimus on the APO ratio in pregnant patients with lupus nephritis, and the impact of combined tacrolimus-aspirin therapy on the APO ratio relative to patients exclusively administered tacrolimus.

RESULTS

Of the 124 pregnancies, 29 were exposed to tacrolimus. Multivariate analysis showed no statistical difference in APO ratio. (overall APO: adjusted odds ratio [aOR], 0.69; 95% confidence interval [CI], 0.23-2.03; p = 0.50; maternal APO: aOR, 1.17; 95% CI, 0.36-3.83; p = 0.80; neonatal APO: aOR, 1.10; 95% CI, 0.38-3.21; p = 0.86; PROMISSE APO: aOR, 0.50; 95% CI, 0.14-1.74; p = 0.27). Blood pressure and estimated glomerular filtration rate (eGFR) during pregnancy and after delivery did not differ between the two groups. Receiver operating characteristic (ROC) curve showed that tacrolimus concentration > 2.6 ng/ml was related to reduced preterm birth rate. (AUC = 0.85, 95% CI: 0.61-1.00, sensitivity: 93% and specificity: 75%). Regarding effect of tacrolimus on lupus nephritis during pregnancy, tacrolimus showed no increased risk of APO, blood pressure or eGFR during pregnancy and after delivery. (overall APO: OR, 1.00; 95% CI, 0.25-4.08; p = 0.98; maternal APO: OR 1.60, 95% CI, 0.39-6.64; p = 0.51; neonatal APO: OR, 0.71; 95% CI, 0.17-3.03; p = 0.65, PROMISSE APO: OR, 0.50; 95% CI, 0.08-3.22; p = 0.47). Tacrolimus-aspirin combination therapy showed a protective tendency against hypertensive disorders during pregnancy, preeclampsia and low birth weight.

CONCLUSIONS

Tacrolimus use during pregnancy with SLE and lupus nephritis showed no significant influence on APO, blood pressure, or renal function; therefore tacrolimus may be suitable for controlling lupus activity during pregnancy. In addition, when using tacrolimus during pregnancy, we should aim its trough concentration ≥ 2.6 ng/ml while paying careful attention to possible maternal side effects of tacrolimus.

TRIAL REGISTRATION

Retrospectively registered.

Blockade of IL-6R prevents preterm birth and adverse neonatal outcomes

BACKGROUND

Preterm birth preceded by spontaneous preterm labour often occurs in the clinical setting of sterile intra-amniotic inflammation (SIAI), a condition that currently lacks treatment.

METHODS

Proteomic and scRNA-seq human data were analysed to evaluate the role of IL-6 and IL-1α in SIAI. A C57BL/6 murine model of SIAI-induced preterm birth was developed by the ultrasound-guided intra-amniotic injection of IL-1α. The blockade of IL-6R by using an aIL-6R was tested as prenatal treatment for preterm birth and adverse neonatal outcomes. QUEST-MRI evaluated brain oxidative stress in utero. Targeted transcriptomic profiling assessed maternal, foetal, and neonatal inflammation. Neonatal biometrics and neurodevelopment were tested. The neonatal gut immune-microbiome was evaluated using metagenomic sequencing and immunophenotyping.

FINDINGS

IL-6 plays a critical role in the human intra-amniotic inflammatory response, which is associated with elevated concentrations of the alarmin IL-1α. Intra-amniotic injection of IL-1α resembles SIAI, inducing preterm birth (7% vs. 50%, p = 0.03, Fisher's exact test) and neonatal mortality (18% vs. 56%, p = 0.02, Mann-Whitney U-test). QUEST-MRI revealed no foetal brain oxidative stress upon in utero IL-1α exposure (p > 0.05, mixed linear model). Prenatal treatment with aIL-6R abrogated IL-1α-induced preterm birth (50% vs. 7%, p = 0.03, Fisher's exact test) by dampening inflammatory processes associated with the common pathway of labour. Importantly, aIL-6R reduces neonatal mortality (56% vs. 22%, p = 0.03, Mann-Whitney U-test) by crossing from the mother to the amniotic cavity, dampening foetal organ inflammation and improving growth. Beneficial effects of prenatal IL-6R blockade carried over to neonatal life, improving survival, growth, neurodevelopment, and gut immune homeostasis.

INTERPRETATION

IL-6R blockade can serve as a strategy to treat SIAI, preventing preterm birth and adverse neonatal outcomes.

FUNDING

NICHD/NIH/DHHS, Contract HHSN275201300006C. WSU Perinatal Initiative in Maternal, Perinatal and Child Health.

Dysfunction of ZNF554 promotes ROS-induced apoptosis and autophagy in Fetal Growth Restriction via the p62-Keap1-Nrf2 pathway

Fetal growth restriction (FGR) is one of the most common complications of an abnormal pregnancy. Placental dysplasia has been established as a significant contributing factor to FGR. Zinc finger protein 554 (ZNF554) is a member of the Krüppel-associated box domain zinc finger protein subfamily, primarily expressed in the placenta and essential for maintaining normal pregnancy outcomes. However, its precise role in FGR remains uncertain. In this study, we confirmed that ZNF554 was low expressed in the placenta of the FGR pregnancy. To further elucidate the impact of ZNF554 on trophoblasts, we conducted experiments using siRNA and overexpression plasmids on HTR8/SVneo and JEG3 cells. Our findings revealed that silencing ZNF554 increased apoptosis and inhibited migration and invasion, while overexpression reduced apoptosis and promoted migration and invasion. Notably, ZNF554 knockdown decreased cellular antioxidant capacity and elevated the production of reactive oxygen species (ROS). Conversely, ZNF554 activated the nuclear factor E2-related factor 2 (NRF2) signaling pathway, exerting its antioxidant effects. Additionally, ZNF554 knockdown promoted cellular autophagy by suppressing P62 and enhancing LC3-II/LC3-I expression. Importantly, the antioxidant N-acetylcysteine (NAC) partially mitigated the impact of ZNF554 knockdown on mitochondrial ROS in trophoblast cells and subsequent effects on cellular autophagy and apoptosis. In conclusion, our results suggest that ZNF554 plays a pivotal role in modulating trophoblast cell invasion and may serve as a prognostic marker and potential therapeutic target for FGR.

Chronic kidney disease in children: an update

Chronic kidney disease (CKD) is a major healthcare issue worldwide. However, the prevalence of pediatric CKD has never been systematically assessed and consistent information is lacking in this population. The current definition of CKD is based on glomerular filtration rate (GFR) and the extent of albuminuria. Given the physiological age-related modification of GFR in the first years of life, the definition of CKD is challenging per se in the pediatric population, resulting in high risk of underdiagnosis in this population, treatment delays and untailored clinical management. The advent and spreading of massive-parallel sequencing technology has prompted a profound revision of the epidemiology and the causes of CKD in children, supporting the hypothesis that CKD is much more frequent than currently reported in children and adolescents. This acquired knowledge will eventually converge in the identification of the molecular pathways and cellular response to damage, with new specific therapeutic targets to control disease progression and clinical features of children with CKD. In this review, we will focus on recent innovations in the field of pediatric CKD and in particular those where advances in knowledge have become available in the last years, with the aim of providing a new perspective on CKD in children and adolescents.

Integrated unbiased multiomics defines disease-independent placental clusters in common obstetrical syndromes

BACKGROUND

Placental dysfunction, a root cause of common syndromes affecting human pregnancy, such as preeclampsia (PE), fetal growth restriction (FGR), and spontaneous preterm delivery (sPTD), remains poorly defined. These common, yet clinically disparate obstetrical syndromes share similar placental histopathologic patterns, while individuals within each syndrome present distinct molecular changes, challenging our understanding and hindering our ability to prevent and treat these syndromes.

METHODS

Using our extensive biobank, we identified women with severe PE (n = 75), FGR (n = 40), FGR with a hypertensive disorder (FGR + HDP; n = 33), sPTD (n = 72), and two uncomplicated control groups, term (n = 113), and preterm without PE, FGR, or sPTD (n = 16). We used placental biopsies for transcriptomics, proteomics, metabolomics data, and histological evaluation. After conventional pairwise comparison, we deployed an unbiased, AI-based similarity network fusion (SNF) to integrate the datatypes and identify omics-defined placental clusters. We used Bayesian model selection to compare the association between the histopathological features and disease conditions vs SNF clusters.

RESULTS

Pairwise, disease-based comparisons exhibited relatively few differences, likely reflecting the heterogeneity of the clinical syndromes. Therefore, we deployed the unbiased, omics-based SNF method. Our analysis resulted in four distinct clusters, which were mostly dominated by a specific syndrome. Notably, the cluster dominated by early-onset PE exhibited strong placental dysfunction patterns, with weaker injury patterns in the cluster dominated by sPTD. The SNF-defined clusters exhibited better correlation with the histopathology than the predefined disease groups.

CONCLUSIONS

Our results demonstrate that integrated omics-based SNF distinctively reclassifies placental dysfunction patterns underlying the common obstetrical syndromes, improves our understanding of the pathological processes, and could promote a search for more personalized interventions.

Association between toxic metals, vitamin D and preterm birth in the Maternal-Infant research on environmental chemicals study

BACKGROUND

Toxic metals, like lead, are risk factors for preterm birth (PTB), but few studies have examined low levels found in most Canadians. Vitamin D, which may have antioxidant activity, protects against PTB.

OBJECTIVES

In this study, we investigated the impact of toxic metals (lead, mercury, cadmium and arsenic) on PTB and examined if maternal plasma vitamin D concentrations modify these associations.

METHODS

We investigated whether concentrations of metals in whole blood measured in early and late pregnancy were associated with PTB (<37 weeks) and spontaneous PTB in 1851 live births from the Maternal-Infant Research on Environmental Chemicals Study using discrete time survival analysis. We also investigated whether the risk of PTB was modified by first-trimester plasma 25-hydroxyvitamin D (25OHD) concentrations.

RESULTS

Of 1851 live births, 6.1% (n = 113) were PTBs and 4.9% (n = 89) were spontaneous PTB. A 1 μg/dL increase in blood lead concentrations during pregnancy was associated with an increased risk of PTB (relative risk [RR] 1.48, 95% confidence interval [CI] 1.00, 2.20) and spontaneous PTB (RR 1.71, 95% CI 1.13, 2.60). The risk was higher in women with insufficient vitamin D concentrations (25OHD <50 nmol/L) for both PTB (RR 2.42, 95% CI 1.01, 5.79) and spontaneous PTB (RR 3.04, 95% CI 1.15, 8.04). However, an interaction on the additive scale was not present. Arsenic was associated with a higher risk of PTB (RR 1.10, 95% CI 1.02, 1.19) and spontaneous PTB (RR 1.11, 95% CI 1.03, 1.20) per 1 μg/L.

CONCLUSIONS

Gestational exposure to low levels of lead and arsenic may increase the risk of PTB and spontaneous PTB; individuals with insufficient vitamin D may be more susceptible to the adverse effects of lead. Given our relatively small number of cases, we encourage testing of this hypothesis in other cohorts, especially those with vitamin D-deficient populations.

Preterm rat survival is enhanced by gestational environmental enrichment

Throughout the last decade, the estimated global human preterm birth rate was 10.6 %, with higher rates in Asia, South America, and Africa. Preterm individuals, even in adulthood, are more likely to develop cardiorespiratory, renal, and metabolic disorders. On the other hand, when experimental animals are housed in an enriched environment during gestation, the development of the progeny in utero is accelerated, compared to standard housing conditions. By terminating gestation one and a half days before parturition, we investigated whether environmental enrichment restricted to gestation may have an impact on progeny survival. Our results demonstrate that the gestational enriched environment tripled the rat´s offspring survival, which was associated with decreased expression of anxiety-like behaviors in the pregnant mother. Sex of the offspring was not a factor in determining survival. We discuss the effect of increased secretion of various trophic factors and hormones induced by the enriched environment on progeny survival.

Acute Kidney Injury Is Associated with Higher Serum Cys-C and NGAL Concentrations, and Risk of Mortality in Premature Calves with Respiratory Distress Syndrome

The purpose of the present study was to establish the development of acute kidney injury (AKI) and evaluate the usefulness of kidney-specific biomarkers in diagnosing AKI in premature calves with respiratory distress syndrome (RDS). Ten-term healthy and 70 premature calves with RDS were enrolled. Clinical examination, blood gases, and chemical analysis were performed at admission and 72 h. Serum concentrations of blood urea nitrogen (BUN), creatinine (Cre), phosphorus (P), cystatin-C (Cys-C), neutrophil gelatinase-associated lipocalin (NGAL), uromodulin (UMOD), and liver-type fatty acid-binding protein (L-FABP) were measured to evaluate kidney injury. Our findings showed that 38.5% of the premature calves with RDS developed AKI. The RDS-AKI group had a 4-fold higher mortality risk than the RDS-non-AKI group. Cys-C, with 90% and 89% specificity, and NGAL, with 100% sensitivity and 85% specificity, were the most reliable biomarkers to determine AKI in premature calves. The usefulness of any biomarker to predict mortality was not found to be convincing. In conclusion, AKI can develop as a consequence of hypoxia in premature calves and may increase the risk of mortality. In addition, serum Cys-C and NGAL concentrations may be useful in the diagnosis of AKI in premature calves with RDS.

Urine podocyte mRNA loss in preterm infants and related perinatal risk factors

BACKGROUND

Preterm birth has been identified as a risk factor for development of long-term chronic kidney disease. Podocyte loss has been reported to contribute to this process in preterm animal models. However, details about podocyte loss in preterm infants and related perinatal risk factors have not been well clarified.

METHODS

Forty full-term infants and 106 preterm infants were enrolled. Urine samples were collected from full-term infants within 4-7 days of birth and preterm infants at 37-40 weeks of corrected age. Levels of urine podocin mRNA, urine protein (UP), and urine microalbumin (UMA) were measured, and the relationship between these markers was evaluated. Clinical information in these infants was collected, and potential correlates that may lead to increased podocyte loss during the perinatal period were identified using linear regression analysis.

RESULTS

Urine podocyte loss indicated by the urine podocin mRNA to creatinine ratio (UpodCR) was higher in preterm infants than in full-term infants. UpodCR was correlated with the levels of UP and UMA. Multiple linear regression analysis also showed that lower gestational age (GA) at birth and small for gestational age (SGA) were high risk factors for urine podocyte loss.

CONCLUSIONS

Increasing urine podocyte loss was identified in preterm infants. Moreover, perinatal factors were associated with podocyte loss and may be a potential direction for comprehensive research and intervention in this field. A higher resolution version of the Graphical abstract is available as Supplementary information.

Burden of Comorbidities and Healthcare Resource Utilization Among Medicaid-Enrolled Extremely Premature Infants

Background: The effect of gestational age (GA) on comorbidity prevalence, healthcare resource utilization (HCRU), and all-cause costs is significant for extremely premature (EP) infants in the United States. Objectives: To characterize real-world patient characteristics, prevalence of comorbidities, rates of HCRU, and direct healthcare charges and societal costs among premature infants in US Medicaid programs, with respect to GA and the presence of respiratory comorbidities. Methods: Using International Classification of Diseases, Ninth/Tenth Revision, Clinical Modification codes, diagnosis and medical claims data from 6 state Medicaid databases (1997-2018) of infants born at less than 37 weeks of GA (wGA) were collected retrospectively. Data from the index date (birth) up to 2 years corrected age or death, stratified by GA (EP, ≤28 wGA; very premature [VP], >28 to <32 wGA; and moderate to late premature [M-LP], ≥32 to <37 wGA), were compared using unadjusted and adjusted generalized linear models. Results: Among 25 573 premature infants (46.1% female; 4462 [17.4%] EP; 2904 [11.4%] VP; 18 207 [71.2%] M-LP), comorbidity prevalence, HCRU, and all-cause costs increased with decreasing GA and were highest for EP. Total healthcare charges, excluding index hospitalization and all-cause societal costs (US dollars), were 2 to 3 times higher for EP than for M-LP (EP $74 436 vs M-LP $27 541 and EP $28 504 vs M-LP $15 892, respectively). Conclusions: Complications of preterm birth, including prevalence of comorbidities, HCRU, and costs, increased with decreasing GA and were highest among EP infants during the first 2 years in this US analysis.

Regulation of nephron progenitor cell lifespan and nephron endowment

Low nephron number - resulting, for example, from prematurity or developmental anomalies - is a risk factor for the development of hypertension, chronic kidney disease and kidney failure. Considerable interest therefore exists in the mechanisms that regulate nephron endowment and contribute to the premature cessation of nephrogenesis following preterm birth. The cessation of nephrogenesis in utero or shortly after birth is synchronized across multiple niches in all mammals, and is coupled with the exhaustion of nephron progenitor cells. Consequently, no nephrons are formed after the cessation of developmental nephrogenesis, and lifelong renal function therefore depends on the complement of nephrons generated during gestation. In humans, a tenfold variation in nephron endowment between individuals contributes to differences in susceptibility to kidney disease; however, the mechanisms underlying this variation are not yet clear. Salient advances in our understanding of environmental inputs, and of intrinsic molecular mechanisms that contribute to the regulation of cessation timing or nephron progenitor cell exhaustion, have the potential to inform interventions to enhance nephron endowment and improve lifelong kidney health for susceptible individuals.

Atherosclerotic Cardiovascular Risk as an Emerging Priority in Pediatrics

Over the last decades, childhood and adolescence have emerged as an important window of opportunity to prevent atherosclerotic cardiovascular disease (ASCVD) later in life. Here, we discuss the underlying advances in the field. First, atherosclerosis development starts as early as childhood. Atherogenesis initiates in the iliac arteries and abdominal aorta and subsequently develops in higher regions of the arterial tree, as has been demonstrated in nonhuman primate studies and human autopsy studies. Obesity, hypertension, hyperlipidemia, and hyperglycemia at a young age can accelerate atherogenesis. Children and adolescents with obesity have a relative risk of ∼ 2.5 for ASCVD mortality later in life, compared to peers with a normal weight. Conversely, early prevention improves long-term cardiovascular outcomes. Second, we review disease-associated factors that add to the traditional risk factors. Various pediatric disorders carry similar or even higher risks of ASCVD than obesity, including chronic inflammatory disorders, organ transplant recipients, familial hypercholesterolemia, endocrine disorders, childhood cancer survivors, chronic kidney diseases, congenital heart diseases, and premature birth, especially after fetal growth restriction. The involved disease-associated factors that fuel atherogenesis are diverse and include inflammation, vascular, and endothelial factors. The diverse and growing list of pediatric groups at risk underscores that cardiovascular risk management has solidly entered the realm of general pediatrics. In a second review in this series, we will, therefore, focus on recent advances in cardiovascular risk assessment and management and their implications for pediatric practice.

Preterm birth and metabolic implications on later life: A narrative review focused on body composition

Preterm newborn infants are characterized by low body weight and lower fat mass at birth compared with full-term newborn neonates. Conversely, at term corrected age, body fat mass is more represented in preterm newborn infants, causing a predisposition to developing metabolic syndrome and cardiovascular diseases in later life with a different risk profile in men as compared with women. Postnatal growth is a complex change in anthropometric parameters and body composition. Both quantity and quality of growth are regulated by several factors such as fetal programming, early nutrition, and gut microbiota. Weight gain alone is not an optimal indicator of nutritional status as it does not accurately describe weight quality. The analysis of body composition represents a potentially useful tool to predict later metabolic and cardiovascular risk as it detects the quality of growth by differentiating between fat and lean mass. Longitudinal follow-up of preterm newborn infants could take advantage of body composition analysis in order to identify high-risk patients who apply early preventive strategies. This narrative review aimed to examine the state-of-the-art body composition among born preterm children, with a focus on those in the pre-school age group.

Under-Recognition of Neonatal Acute Kidney Injury and Lack of Follow-Up

OBJECTIVE

Acute kidney injury (AKI) incidence is 30% in neonatal intensive care units (NICU). AKI is associated with increased mortality and risk of chronic kidney disease (CKD) in children. To assess follow-up and early CKD, we retrospectively reviewed outcomes of Cincinnati Children's Hospital Medical Center (CCHMC) cohort of neonates from the AWAKEN trial (2014).

STUDY DESIGN

Data from 81 CCHMC patients were extracted from the AWAKEN dataset. KDIGO (Kidney Disease: Improving Global Outcomes) criteria for serum creatinine (SCr) and urine output (UOP) <1 mL/kg/h, reported per 24 hours on postnatal days 2 to 7, were used to define AKI. Charts were reviewed until May 2019 for death, nephrology consult, AKI diagnosis on discharge summary, follow-up, and early CKD at >6 months of age (defined as: estimated glomerular filtration rate < 90 mL/min/1.73 m², hyperfiltration, proteinuria, hypertension, or abnormal ultrasound). Patients were considered to have renal follow-up if they had ≥1 follow-up visit containing: SCr, urinalysis, or blood pressure measurement.

RESULTS

Seventy-seven patients had sufficient data to ascertain AKI diagnosis. In total 47 of 77 (61%) were AKI+ by SCr or UOP criteria (20 stage 1, 14 stage 2, 13 stage 3). Four died during their admission and five were removed from CKD analyses due to urologic anomalies. AKI-UOP alone outnumbered AKI-SCr (45 AKI+ vs 5 AKI+ for all stages). 33% of patients had <2 SCr measured while inpatient. Only 3 of 47 AKI+ patients had a nephrology consult (all stage 3 by SCr) and 2 of 47 had AKI included in discharge summary. 67% of AKI+ patients had follow-up. In total 10 of 43 (23%) AKI+ versus 12 of 25 (48%) AKI- patients had ≥1 marker of early CKD assessed after 6 months. Based on SCr, 3 of 7 (43%) AKI+ had hyperfiltration versus 0 of 7 (0%) AKI- (p = 0.19).

CONCLUSION

AKI is vastly under-recognized in the NICU, especially if based on SCr alone. This leads to insufficient follow-up to ascertain renal sequelae in this high-risk population.

KEY POINTS

· AKI is under-recognized in high-risk neonates.. · There is a lack of adequate follow-up.. · Identification of AKI by SCr alone is insufficient..

Effect of maternal vitamin D status on risk of adverse birth outcomes: a systematic review and dose-response meta-analysis of observational studies

PURPOSE

Accumulating evidence suggests that vitamin D deficiency increases the risk of adverse perinatal outcomes. However, the dose-response relationship between maternal vitamin D status and adverse birth outcomes remains unclear. Focusing on prospective observational studies, we aimed to explore the dose-response relationship of vitamin D status with the risk of low birth weight (LBW), macrosomia (MA), preterm birth (PTB), small for gestational age (SGA), and intrauterine growth restriction (IUGR).

METHODS

Databases including PubMed, Embase, Scopus, and Web of Science were used up to 19 January 2021 to search for observational studies that fulfilled criteria as follows: cohort studies, case-cohort studies, or nested case-control studies. Random-effects models were used to pool relative risks (RRs) and 95% confidence intervals (CIs) in the observational studies.

RESULTS

A total of 72 publications were included in this systematic review and 71 in the meta-analysis. Maternal 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with the risk of LBW (RR: 0.65; 95% CI 0.48-0.86), PTB (RR: 0.67; 95% CI 0.57-0.79), and SGA (RR: 0.61; 95% CI 0.49-0.76) in the highest versus lowest meta-analysis, but not associated with MA and IUGR. Linear dose-response analysis showed that each 25 nmol/L increase in 25(OH)D was associated with a 6% and 10% reduction in the risk of PTB (RR: 0.94; 95% CI 0.90-0.98) and SGA (RR: 0.90; 95% CI 0.84-0.97), respectively.

CONCLUSION

Our study suggests that a sufficient vitamin D status during pregnancy is protective against the risk of LBW, PTB, and SGA.

Association between perinatal factors and future risk for gout-a nested case-control study

Background

Increased level of urate is the strongest risk factor for gout development but since only a minority of hyperuricemics are affected by gout, other pathogenic factors must be considered. Low birth weight is associated with future morbidities causing hyperuricemia, such as diabetes and renal disease. The purpose of this study was to investigate if, and to what extent, maternal and perinatal factors, including birth weight, are associated with future risk of being diagnosed with gout.

Methods

A population-based retrospective nested case-control registry study based on regional and national health care registers in Sweden. All incident cases of gout born in 1973 and onward who had received ≥1 diagnosis of gout from 2000 through 2019 in the region of western Sweden were included. Up to 5 non-gout controls were matched to each case by age, sex, and county at the year of first gout diagnosis. A range of maternal, gestational, and perinatal factors were analyzed for their potential association to future gout development. This included the health of the mother, gestational length, birth weight, number of siblings, and congenital malformations.

Results

Maternal diabetes, any congenital malformation, and being small for gestational age were factors that significantly increased the risk for future gout development, odds ratio (95% CI) 3.1 (1.3 to 7.4) (p=0.01), 1.33 (1.04 to 1.7) (p=0.02), and 1.75 (1.3 to 2.3) (p<.0001), respectively.

Conclusions

In this study, maternal diabetes and being small for gestational age increased the risk for future gout development in young adults. As of today, these conditions are becoming more prevalent and may contribute to the ongoing gout epidemic. These results require both confirmation and further delineation of underlying mechanisms.

Pregnancy in Women With Preexisting Glomerular Diseases: A Single-Center Experience

Aim

Women with glomerular diseases are often of childbearing age. Besides lupus nephritis, data regarding pregnancy in patients with glomerular diseases are limited, posing a challenging task to attending nephrologists. This study aimed to investigate the pregnancy outcomes and the impact on the underlying glomerular disease among women followed in our institution.

Methods

A single-center retrospective cohort study of women with biopsy-proven glomerular diseases who experienced pregnancy between 2010 and 2020. We analyzed data before, during, and after gestation.

Results

A total of 22 women, 13 women with primary and 9 women with secondary glomerular diseases, were included in this study. Most patients (82%) had received immunosuppressive treatment at various times before pregnancy. All the women were in remission, either complete (62%) or partial (38%), with well-preserved renal function (82%) before conception. A total of 30 live births and 1 stillbirth were recorded; the rate of preterm delivery was 23%. Renal function and proteinuria remained stable during pregnancy. Preeclampsia was observed in 6.7% of patients and disease relapse in 6.9% of the pregnancies.

Conclusion

Pregnancy was associated with a low frequency of adverse events in women with underlying glomerular diseases, provided they have quiescent disease and preserved renal function.

Lower hypothalamus subunit volumes link with impaired long-term body weight gain after preterm birth

INTRODUCTION

Preterm birth is associated with an increased risk for impaired body weight gain. While it is known that in prematurity several somatic and environmental factors (e.g., endocrine factors, nutrition) modulate short- and long-term body weight gain, the contribution of potentially impaired body weight control in the brain remains elusive. We hypothesized that the structure of hypothalamic nuclei involved in body weight control is altered after preterm birth, with these alterations being associated with aberrant body weight development into adulthood.

MATERIALS AND METHODS

We assessed 101 very preterm (i.e., <32 weeks of gestational age) and/or very low birth weight (i.e., <1500g; VP/VLBW) and 110 full-term born (FT) adults of the population-based Bavarian Longitudinal Study with T1-weighted MRI, deep learning-based hypothalamus subunit segmentation, and multiple body weight assessments from birth into adulthood.

RESULTS

Volumes of the whole hypothalamus and hypothalamus subunits relevant for body weight control were reduced in VP/VLBW adults and associated with birth variables (i.e., gestational age and intensity of neonatal treatment), body weight (i.e., weight at birth and adulthood), and body weight trajectories (i.e., trajectory slopes and cluster/types such as long-term catch-up growth). Particularly, VP/VLBW subgroups, whose individuals showed catch-up growth and/or were small for gestational age, were mostly associated with volumes of distinct hypothalamus subunits such as lateral or infundibular/ventromedial hypothalamus.

CONCLUSION

Results demonstrate lower volumes of body weight control-related hypothalamus subunits after preterm birth that link with long-term body weight gain. Data suggest postnatal development of body weight -related hypothalamic nuclei in VP/VLBW individuals that corresponds with distinct body weight trajectories into adulthood.

Educational Review: The Impact of Perinatal Oxidative Stress on the Developing Kidney

Oxidative stress occurs when there is an imbalance between reactive oxygen species/reactive nitrogen species and antioxidant systems. The interplay between these complex processes is crucial for normal pregnancy and fetal development; however, when oxidative stress predominates, pregnancy related complications and adverse fetal programming such as preterm birth ensues. Understanding how oxidative stress negatively impacts outcomes for the maternal-fetal dyad has allowed for the exploration of antioxidant therapies to prevent and/or mitigate disease progression. In the developing kidney, the negative impact of oxidative stress has also been noted as it relates to the development of hypertension and kidney injury mostly in animal models. Clinical research addressing the implications of oxidative stress in the developing kidney is less developed than that of the neurodevelopmental and respiratory conditions of preterm infants and other vulnerable neonatal groups. Efforts to study the oxidative stress pathway along the continuum of the perinatal period using a team science approach can help to understand the multi-organ dysfunction that the maternal-fetal dyad sustains and guide the investigation of antioxidant therapies to ameliorate the global toxicity. This educational review will provide a comprehensive and multidisciplinary perspective on the impact of oxidative stress during the perinatal period in the development of maternal and fetal/neonatal complications, and implications on developmental programming of accelerated aging and cardiovascular and renal disease for a lifetime.

Postnatal glucocorticoid use impacts renal function in VLBW neonates

BACKGROUND

Preterm neonates often require glucocorticoids to manage refractory hypotension, prevent, and treat bronchopulmonary dysplasia. We have investigated the effect of cumulative dose and duration of glucocorticoids on blood pressure and renal function in VLBW infants.

METHODS

In this retrospective cohort study, medical records of infants (GA ≤ 35 weeks) born January 2015 to December 2019 were reviewed to extract demographic and clinical characteristics, dose and duration of steroids, blood pressure (BP), and creatinine at the time of discharge from the neonatal intensive care unit.

RESULTS

Two hundred and eighty-three neonates with average GA (28 ± 3 weeks) and birthweight (1060±381 g). Twenty-eight percent (33/116) of infants who received postnatal steroids developed hypertension versus 16% (27/167) of controls (OR = 2.0, p = 0.011). There was a correlation between the cumulative dosage of postnatal steroids and systolic BP (R² = 0.06, p < 0.001). With increasing steroid dose and total steroid days, there was a significant increase in creatinine clearance at the time of discharge (R² = 0.13, p < 0.001; R² = 0.13, p < 0.001, respectively).

CONCLUSIONS

Cumulative dose of postnatal steroids and duration of use is associated with increased systolic BP in premature infants. Postnatal steroids should be used prudently to prevent long-term cardiovascular and renal morbidity.

IMPACT

Preterm neonates are exposed to a high dose of glucocorticoids during their neonatal intensive care stay. The dose and duration of use of postnatal glucocorticoids was associated with significant increase in blood pressure at the time of discharge in preterm neonates. Postnatal glucocorticoid use is associated with improved creatinine clearance likely due to a state of hyperfiltration and may lead to chronic kidney disease later in life. Postnatal glucocorticoids should be used prudently in this highly vulnerable population.

Epigenetic Mechanisms Responsible for the Transgenerational Inheritance of Intrauterine Growth Restriction Phenotypes

A poorly functioning placenta results in impaired exchanges of oxygen, nutrition, wastes and hormones between the mother and her fetus. This can lead to restriction of fetal growth. These growth restricted babies are at increased risk of developing chronic diseases, such as type-2 diabetes, hypertension, and kidney disease, later in life. Animal studies have shown that growth restricted phenotypes are sex-dependent and can be transmitted to subsequent generations through both the paternal and maternal lineages. Altered epigenetic mechanisms, specifically changes in DNA methylation, histone modifications, and non-coding RNAs that regulate expression of genes that are important for fetal development have been shown to be associated with the transmission pattern of growth restricted phenotypes. This review will discuss the subsequent health outcomes in the offspring after growth restriction and the transmission patterns of these diseases. Evidence of altered epigenetic mechanisms in association with fetal growth restriction will also be reviewed.

Plasma copeptin is increased and associated with smaller kidney volume in young adults born very preterm

Background

Plasma copeptin, a surrogate marker for vasopressin levels, is increased in neonates born preterm, particularly in those with a more severe neonatal course, as reflected by bronchopulmonary dysplasia. Copeptin levels in adulthood are unknown.

Methods

In this case–control study of 101 adults born very preterm (<30 weeks of gestation) and 105 control adults born full-term, a comprehensive clinical and biological assessment was performed, including blood pressure measurements, kidney ultrasound and determination of plasma copeptin, renin activity, angiotensin II, aldosterone, apelin, sodium and potassium, serum and morning urine osmolality.

Results

The median age in the study was 23.1 years [interquartile range (IQR) 21.2–24.8] and 57% were females. In males, the median copeptin levels were 8.2 pmol/L (IQR 6.3–12.4) and 6.1 pmol/L (IQR 4.3–9.0) in the preterm and term groups, respectively (P = 0.022). In females, the median copeptin levels were 5.2 pmol/L (IQR 3.9–7.6) and 4.0 pmol/L (IQR 2.8–5.7) in the preterm and term groups, respectively (P = 0.005). Adults born preterm with a history of bronchopulmonary dysplasia had further increased copeptin levels. The kidney volume, adjusted for height, was smaller and albuminuria was higher in the preterm group, and both were associated with higher plasma copeptin levels.

Conclusions

Plasma copeptin is higher in young adults born preterm and is related to a more severe neonatal course and smaller kidney volume.

Cardiovascular impact and sequelae of bronchopulmonary dysplasia

The development, growth, and function of the cardiac, pulmonary, and vascular systems are closely intertwined during both fetal and postnatal life. In utero, placental, environmental, and genetic insults may contribute to abnormal pulmonary alveolarization and vascularization that increase susceptibility to the development of bronchopulmonary dysplasia (BPD) in preterm infants. However, the shared milieu of stressors may also contribute to abnormal cardiac or vascular development in the fetus and neonate, leading to the potential for cardiovascular dysfunction. Further, cardiac or pulmonary maladaptation can potentiate dysfunction in the other organ, amplify the risk for BPD in the neonate, and increase the trajectory for overall neonatal morbidity. Beyond infancy, there is an increased risk for systemic and pulmonary vascular disease including hypertension, as well as potential cardiac dysfunction, particularly within the right ventricle. This review will focus on the cardiovascular antecedents of BPD in the fetus, cardiovascular consequences of preterm birth in the neonate including associations with BPD, and cardiovascular impact of prematurity and BPD throughout the lifespan.

Longitudinal Changes in Serum Creatinine Levels and Urinary Biomarkers in Late Preterm Infants during the First Postnatal Week: Association with Acute Kidney Injury and Treatment with Aminoglycoside

We aimed to determine the incidence of acute kidney injury (AKI) and longitudinal changes in SCr levels and urinary biomarkers associated with AKI and aminoglycoside (AG) medication during the first week of life of late preterm infants. Urine biomarkers and SCr were measured in thirty late preterm infants on days one, two, five, and seven postnatal. Urine biomarkers included neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemotactic protein-1 (MCP-1), epidermal growth factor (EGF), Tamm-Horsfall glycoprotein (THP), and liver fatty-acid-binding protein (L-FABP). Gestational age was positively correlated with SCr levels at birth, but inversely correlated with SCr levels at day five and day seven. Eighteen (60%) infants had stage 1 AKI, and twenty (67%) infants were treated with AGs. Infants with AKI had lower gestational age and lower birth weight than those without AKI. Urinary biomarkers adjusted according to uCr levels in infants with AKI were not statistically different from those in infants without AKI. There were no significant differences in incidence of AKI, and SCr levels during and after cessation of AG treatment. The uMCP-1/Cr ratio at days five and seven was higher in infants treated with AG than in non-treated infants.

Urinary Levels of Cathepsin B in Preterm Newborns

Increased investment in perinatal health in developing countries has improved the survival of preterm newborns, but their significant multiorgan immaturity is associated with short and long-term adverse consequences. Cathepsin B, as a protease with angiogenic properties, may be related to the process of nephrogenesis. A total of 88 neonates (60 premature children, 28 healthy term children) were included in this prospective study. We collected urine samples on the first or second day of life. In order to determine the concentration of cathepsin B in the urine, the commercially available enzyme immunoassay was used. The urinary concentrations of cathepsin B normalized with the urinary concentrations of creatinine (cathepsin B/Cr.) in newborns born at 30-34, 35-36, and 37-41 (the control group) weeks of pregnancy were (median, Q1-Q3) 4.00 (2.82-5.12), 3.07 (1.95-3.90), and 2.51 (2.00-3.48) ng/mg Cr, respectively. Statistically significant differences were found between the group of newborns born at 30-34 weeks of pregnancy and the control group (p < 0.01), and between early and late preterm babies (PTB) (p < 0.05). The group of children born at 35-36 weeks of pregnancy and the control group did not differ significantly. This result suggests that the elevated urinary cathepsin B/Cr. level may be the result of the kidneys' immaturity in preterm newborns.

Biomarkers of renal function in preterm neonates at 72h and 3weeks of life

OBJECTIVE

Serum levels of creatinine in neonates are quite variable and suffer interference from the immature kidney and maternal creatinine concentration. The aim of this study was to measure novel biomarkers of glomerular and tubular function in healthy preterm neonates at 72h and 3 weeks of life.

METHODS

Urine samples were collected in 40 preterm neonates with 28-34 incomplete weeks of gestational age. None of the participants had comorbidities, malformations and infections. The samples were collected at 72h of life and at 3 weeks after birth. Measurements of Calbindin, Collagen IV, FABP1, αGST, IP-10, KIM-1, Osteoactivin, Renin, TFF-3, TIMP-1, α-1-Microglobulin, Albumin, Clusterin, Cystatin C, EGF, Lipocalin-2/NGAL and Osteopontin were performed using panels 1 and 2 of multiplex kits of kidney injury. Data were analyzed using the software GraphPad Prism version 6.0.

RESULTS

The preterm neonates included 55% of males with gestational age of 30±1 weeks. The most frequent maternal condition associated with preterm birth was preeclampsia (80%). Molecules related to glomerular function showed a significant increase in the concentrations obtained at 3 weeks of life compared to 72h of life. Markers related to tubular injury (KIM-1 and NGAL) also showed an increase. On the other hand, cystatin C did not change.

CONCLUSION

The elevation of molecules related to glomerular function indicates an increase of glomerular filtration rate from 72h up until 3 weeks of life, which was not clearly detected with the measurement of cystatin C.

Long-term kidney function and survival in recipients of allografts from living kidney donors with hypertension: a national cohort study

Allografts from living kidney donors with hypertension may carry subclinical kidney disease from the donor to the recipient and, thus, lead to adverse recipient outcomes. We examined eGFR trajectories and all-cause allograft failure in recipients from donors with versus without hypertension, using mixed-linear and Cox regression models stratified by donor age. We studied a US cohort from 1/1/2005 to 6/30/2017; 49 990 recipients of allografts from younger (<50 years old) donors including 597 with donor hypertension and 21 130 recipients of allografts from older (≥50 years old) donors including 1441 with donor hypertension. Donor hypertension was defined as documented predonation use of antihypertensive therapy. Among recipients from younger donors with versus without hypertension, the annual eGFR decline was -1.03 versus -0.53 ml/min/m² (P = 0.002); 13-year allograft survival was 49.7% vs. 59.0% (adjusted allograft failure hazard ratio [aHR] 1.23; 95% CI 1.05-1.43; P = 0.009). Among recipients from older donors with versus without hypertension, the annual eGFR decline was -0.67 versus -0.66 ml/min/m² (P = 0.9); 13-year allograft survival was 48.6% versus 52.6% (aHR 1.05; 95% CI 0.94-1.17; P = 0.4). In secondary analyses, our inferences remained similar for risk of death-censored allograft failure and mortality. Hypertension in younger, but not older, living kidney donors is associated with worse recipient outcomes.

The progression of serum cystatin C concentrations within the first month of life after preterm birth-a worldwide systematic review

Multiple single-center studies have examined the progression of kidney function biomarkers such as serum cystatin C (Cys C) in the first 30 days of life (DOL) after preterm birth, but from different ethnicities and in different gestational ages (GA), without a functional summary available. We performed a systematic literature review within PubMed, Google Scholar, and Scopus, with additional use of the snowballing method to find studies including data on serum Cys C concentrations in the first 30 DOL. We identified 15 papers that met criteria, published from 2000 to 2019, from 10 countries across 4 continents, in 1468 babies born preterm. Cys C was superior to creatinine in 11/13 studies, and equal in 2/13. For infants born at 24-28 weeks GA, the DOL1 Cys C concentrations ranged from 1.44 to 1.90 mg/L, from 1.20 to 1.77 on DOL3, and from 1.36 to 2.02 between DOL 4 and 30. For infants born at 29-33 weeks GA, the DOL1 Cys C values ranged from 1.41 to 1.96 mg/L, from 1.28 to 1.70 on DOL3, and 1.51 to 1.87 between DOL 4 and 30. For preterm infants born after 34 weeks GA, the DOL1 Cys C values ranged from 1.22 to 1.96 mg/L, from 1.24 to 1.85 on DOL3, and 1.22 to 1.82 between DOL 4 and 30. This systematic review provides generalizable worldwide reference data on Cys C that could be used to estimate progression or resolution of abnormal kidney function in the first months after preterm birth, stratified by GA.

Childhood risk factors for adulthood chronic kidney disease

Chronic kidney disease (CKD) is a major public health challenge, affecting as much as 8 to 18% of the world population. Identifying childhood risk factors for future CKD may help clinicians make early diagnoses and initiation of preventive interventions for CKD and its attendant comorbidities as well as monitoring for complications. The purpose of this review is to describe childhood risk factors that may predict development of overt kidney disease later in life. Currently, there are multiple childhood risk factors associated with future onset and progression of CKD. These risk factors can be grouped into five categories: genetic factors (e.g., monogenic or risk alleles), perinatal factors (e.g., low birth weight and prematurity), childhood kidney diseases (e.g., congenital anomalies, glomerular diseases, and renal cystic ciliopathies), childhood onset of chronic conditions (e.g., cancer, diabetes, hypertension, dyslipidemia, and obesity), and different lifestyle factors (e.g., physical activity, diet, and factors related to socioeconomic status). The available published information suggests that the lifelong risk for CKD can be attributed to multiple factors that appear already during childhood. However, results are conflicting on the effects of childhood physical activity, diet, and dyslipidemia on future renal function. On the other hand, there is consistent evidence to support follow-up of high-risk groups.

Renal insufficiency in children born preterm: examining the role of neonatal acute kidney injury

OBJECTIVE

To identify the prevalence of renal insufficiency (RI) in children with a history of prematurity and acute kidney injury (AKI).

STUDY DESIGN

This prospective cohort study evaluated renal function in children born preterm at 5-9 years of age. Univariable analyses compared perinatal and follow-up data from subjects with and without AKI history, and with and without current RI. Regression analyses were attempted to model RI as a function of AKI and other clinical risk factors.

RESULTS

Fifteen of 43 (35%) participants had previously undiagnosed RI. Only children with no AKI history or neonatal stage 1 AKI presented for follow-up. Children born preterm with a history of stage 1 AKI had higher serum creatinine (sCr) at follow-up, but were not more likely to have RI compared to children without stage 1 AKI history (RI prevalence 30% and 36% in AKI and non-AKI group, respectively).

CONCLUSION

The high prevalence of RI in this preterm cohort at middle childhood follow-up highlights the need for routine kidney health assessments in this population. Large multicenter studies are needed to further characterize the impact of premature birth and mild AKI on renal function throughout childhood.

Assessment of nephron number and single-nephron glomerular filtration rate in a clinical setting

Total nephron counts vary widely between individuals and may affect susceptibility to certain diseases, including hypertension and chronic kidney disease. Detailed analyses of whole kidneys collected from autopsy patients remain the only method for accurately counting nephrons in humans, with no equivalent option in living subjects. Current technological advances have enabled estimations of nephron numbers in vivo, particularly the use of total nephron number and whole-kidney glomerular filtration rate to estimate the mean single-nephron glomerular filtration rate. The use of this method would allow physicians to detect dynamic changes in filtration function at the single-nephron level rather than to simply count the number of nephrons that appear to be functioning. Currently available methods for estimating total nephron number in clinical practice have the potential to overcome limitations associated with autopsy analyses and may therefore pave the way for new therapeutic interventions and improved clinical outcomes.

Melatonin for the Management of Preeclampsia: A Review

Preeclampsia is a disease specific to pregnancy characterised by new-onset hypertension with maternal organ dysfunction and/or fetal growth restriction. It remains a major cause of maternal and perinatal morbidity and mortality. For sixty years, antihypertensives have been the mainstay of treating preeclampsia and only recently have insights into the pathogenesis of the disease opened new avenues for novel therapies. Melatonin is one such option, an endogenous and safe antioxidant, that may improve the maternal condition in preeclampsia while protecting the fetus from a hostile intrauterine environment. Here we review the evidence for melatonin as a possible adjuvant therapy for preeclampsia, including in vitro evidence supporting a role for melatonin in protecting the human placenta, preclinical models, vascular studies, and clinical studies in hypertension and pregnancy.

Biomarkers of Kidney Injury in Very-low-birth-weight Preterm Infants: Influence of Maternal and Neonatal Factors

BACKGROUND/AIM

Acute kidney injury is an important cause of mortality in very-low-birth-weight (VLBW) preterm infants. As in the general population, the detection of renal damage cannot rely on the measurement of serum creatinine, since it has been demonstrated to be a weak predictor and a delayed indicator of kidney function deterioration. However, several candidate biomarkers have failed to prove sufficient specificity and sensitivity for a routine clinical use because of the poor awareness of their biological role. This study was aimed to investigate the impact of different maternal and neonatal conditions on several renal biomarkers in VLBW preterm infants during the first week of life.

PATIENTS AND METHODS

Preterm infants<32 weeks' gestation and <1500g were enrolled. We measured urinary biomarkers kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, epidermal growth factor (EGF) and osteopontin (OPN) on the 1^st, 3^rd, and 7^th day after birth.

RESULTS

Thirty-tree infants were included. The multivariate analysis showed a significant association between gestational age, the presence of patent ductus arteriosus, antenatal maternal hypertension and the levels of urinary biomarkers.

CONCLUSION

There is a possible relation between early biomarkers of renal injury and antenatal, perinatal and post-natal characteristics in VLBW preterm infants during the first week of life.

Environmental cadmium exposure induces fetal growth restriction via triggering PERK-regulated mitophagy in placental trophoblasts

Cadmium (Cd), an environmental toxicant, is positively associated with fetal growth restriction (FGR). However, the mechanism by which gestational exposure to Cd induces FGR remains unclear. This study designed in vitro and in vivo experiments to explore the role of placental mitophagy in Cd-impaired fetal growth. Based on our case-control study, we also investigated the association of placental mitophagy with reduced progesterone (P4) level and all-cause FGR. We firstly found environmental Cd exposure lowered the P4 content in maternal sera, placentae and amnioticfluids of mice. The level of three mitochondrial P4 synthases, including StAR, CYP11A1 and 3β-HSD, was also reduced in Cd-treated placentae. Furthermore, Cd triggered mitophagy, as determined by the degradation of two mitochondrial proteins HSP60 and COX IV, and the accumulation of co-localizations of TOM20 with LC3B or Parkin in placental trophoblasts. Correspondingly, Cd elevated mitochondrial Parkin level in placental trophoblasts. Mdivi-1, a mitophagy inhibitor, obviously attenuated Cd-induced reduction of placental P4 and FGR in mice. Moreover, mdivi-1 and Parkin siRNA (siR) markedly reversed Cd-caused P4 synthesis inhibition in human placental trophoblasts. Interestedly, the PERK/ATF4 signaling was activated in Cd-stimulated placental trophoblasts. PERK siR inhibited mitochondrial proteins degradation in Cd-stimulated placental trophoblasts. In particularly, mitophagy activation and P4 synthesis suppression occurred in small-for-gestational-age placentae based on our case-control study. Environmental Cd exposure induced FGR via activating PERK-regulated mitophagy and inhibiting P4 synthesis in placentaltrophoblasts. Furthermore, placental mitophagy was related to the reduced progesterone level and all-cause fetal growth restriction based on our case-control study. As above, placental mitophagy maybe the common mechanism of environmental toxicants-impaired fetal growth.

Melatonin protects against environmental stress-induced fetal growth restriction via suppressing ROS-mediated GCN2/ATF4/BNIP3-dependent mitophagy in placental trophoblasts

Gestational exposure to environmental stress induces fetal growth restriction (FGR), and thereby increasing the risk of infant death and chronic noncommunicable diseases in adults. However, the mechanism by which environmental stress induces FGR remains unclear. Based on case-control study, we found that the reduced level of melatonin (MT), a major secretory product from the pineal gland, was observed in placentae of FGR. This work was to investigate the protective effect of MT on environmental stress-caused FGR and its mechanisms. We used cadmium (Cd) as an environmental stressor to stimulate pregnant mice and thereby establishing a FGR model. The data showed that maternal Cd exposure lowered the P4 concentration in maternal sera, placentae and amniotic fluid, and caused FGR. Correspondingly, the expression of CYP11A1, a critical P4 synthase, was markedly downregulated in Cd-treated placentae. Simultaneously, Cd triggered BNIP3-dependent mitophagy in placental trophoblasts, as determined by the degradation of mitochondrial proteins, including HSP60 and COX IV, and the accumulation of puncta representing co-localization of TOM20 with LC3B or BNIP3 with LC3B. Based on our case-control study, we also found that activated BNIP3-dependent mitophagy and P4 synthesis inhibition occurred in SGA placentae. Most importantly, BNIP3 siRNA reversed Cd-induced P4 synthesis suppression in human placental trophoblasts. It is noteworthy that MT alleviated Cd-caused P4 synthesis suppression and FGR via antagonizing BNIP3-dependent mitophagy in placental trophoblasts. Further results confirmed that MT attenuated Cd-triggered BNIP3-dependent mitophagy via blocking GCN2/ATF4 signaling. Amusingly, Cd triggered oxidative stress and then activating GCN2/ATF4 signaling in placental trophoblasts. As expected, MT obviously suppressed Cd-caused reactive oxygen species (ROS) release. In the present study, we propose a neoteric mechanism by which MT protects against environmental stress-impaired P4 synthesis and fetal growth via suppressing ROS-mediated GCN2/ATF4/BNIP3-dependent mitophagy in placental trophoblasts. As above, MT is a potential therapeutic agent antagonizing environmental stress-induced developmental toxicity.

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Melatonin protects against Cd-induced fetal growth restriction.

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Melatonin attenuates Cd-induced placental P4 synthesis inhibition by mitophagy.

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Melatonin suppresses Cd-triggered placental mitophagy via blocking GCN2/ATF4.

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Melatonin blocks Cd-activated placental GCN2/ATF4 signaling via repressing ROS.

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Activated mitophagy and reduced P4 synthesis occur in SGA placentae.

Fibroblast growth factor 23-Klotho and hypertension: experimental and clinical mechanisms

Hypertension (HTN) and chronic kidney disease (CKD) are increasingly recognized in pediatric patients and represent risk factors for cardiovascular morbidity and mortality later in life. In CKD, enhanced tubular sodium reabsorption is a leading cause of HTN due to augmented extracellular fluid volume expansion. The renin-angiotensin-aldosterone system (RAAS) upregulates various tubular sodium cotransporters that are also targets of the hormone fibroblast growth factor 23 (FGF23) and its co-receptor Klotho. FGF23 inhibits the activation of 1,25-dihydroxyvitamin D that is a potent suppressor of renin biosynthesis. Here we review the complex interactions and disturbances of the FGF23-Klotho axis, vitamin D, and the RAAS relevant to blood pressure regulation and discuss the therapeutic strategies aimed at mitigating their pathophysiologic contributions to HTN.

Asthma prevalence, lung and cardiovascular function in adolescents born preterm

Our main objective was to study respiratory evolution and pulmonary and cardiac function in adolescents born preterm in the post-surfactant era. Observational cross-sectional study, comparing very preterm (< 32 weeks) and moderately-late preterm adolescents (≥ 32 weeks) (74 each group). We recorded respiratory symptoms, spirometry and functional echocardiogram. Very preterm adolescents required more respiratory admissions (45.9% vs. 28.4%) (p = 0.03, OR 2.1, CI95% 1.1–4.2) and had more current asthma (21.6% vs. 9.5%, p = 0.04, OR 2.3, CI95% 1.1–5.2). Preterm subjects with intrauterine growth restriction (IUGR) presented lower FEV₁ (88.7 ± 13.9 vs. 95.9 ± 13.3, p = 0.027) and lower FVC (88.2 ± 13.6 vs. 95.5 ± 13.3, p = 0.025). When assessing right ventricle, very preterm showed a greater E/E’ ratio (p = 0.02) and longer myocardial performance index (MPI) (p = 0.001). Adolescents with IUGR showed less shortening fraction (p = 0.016), worse E/E′ ratio (p = 0.029) and longer MPI (p = 0.06). Regarding left ventricle, very preterm showed less E′ wave velocity (p = 0.03), greater E/E′ ratio (p = 0.005) and longer MPI (p < 0.001). Gestational age < 32 weeks is independently associated with current asthma in adolescence. Children 13–14 years old born very preterm required more respiratory admissions and had poorer diastolic and global function of both ventricles. IUGR is a risk factor for poorer lung function in preterm adolescents, regardless gestational age.

An overview of adult health outcomes after preterm birth

Preterm birth (gestational age < 37 completed weeks) has increased in prevalence in most countries in the past 20 years and now affects nearly 11% of all births worldwide. Because of treatment advances introduced in the 1970s-1980s, >95% of preterm infants who receive modern neonatal and pediatric care now survive into adulthood. The earliest birth cohorts to benefit from those advances are now in their 4th and 5th decades of life. A growing number of large cohort studies have investigated the long-term health sequelae in adulthood. Evidence has consistently shown that adult survivors of preterm birth have increased risks of chronic disorders involving various organ systems, including cardiovascular, endocrine/metabolic, respiratory, renal, neurodevelopmental, and psychiatric disorders, which either persist from childhood into adulthood or sometimes first manifest in adulthood. These disorders also lead to moderately (30% to 50%) increased mortality risks during early to mid-adulthood among persons born preterm compared with full-term, and even higher risks among those born at the earliest gestational ages. However, the majority of persons born preterm have low absolute risks of these outcomes and good self-reported quality of life in adulthood. Priorities for future research include the assessment of long-term health sequelae of preterm birth in racially and economically diverse populations, additional follow-up of existing cohorts into older adulthood, elucidation of outcomes by preterm birth subtype (e.g., different underlying causes) to improve risk stratification, and identification of protective factors that will support the long-term health trajectory and well-being of preterm-born adults.

Trimester-Specific Blood Trihalomethane and Urinary Haloacetic Acid Concentrations and Adverse Birth Outcomes: Identifying Windows of Vulnerability during Pregnancy

BACKGROUND

Some disinfection by-products (DBPs) are reproductive and developmental toxicants in laboratory animals. However, studies of trimester-specific DBP exposure on adverse birth outcomes in humans are inconsistent.

OBJECTIVE

We examined whether trimester-specific blood and urinary biomarkers of DBP were associated with small for gestational age (SGA), low birth weight (LBW), and preterm birth.

METHODS

A total of 4,086 blood and 3,951 urine samples were collected across pregnancy trimesters among 1,660 mothers from Xiaogan City, China. Blood samples were quantified for biomarkers of trihalomethanes (THMs): chloroform (TCM), bromodichloromethane, dibromochloromethane, and bromoform. Urine samples were quantified for biomarkers of haloacetic acids (HAA): dichloroacetic acid and trichloroacetic acid. Birth outcomes were abstracted at delivery from medical records. We used Poisson regression models with log link functions to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for SGA, LBW, and preterm birth across tertiles (or categories) of DBP biomarker concentrations measured across pregnancy trimesters. We also examined the relative exposure differences across gestation comparing adverse outcomes with normal births using mixed-effects models.

RESULTS

Blood TCM concentrations in the second trimester were associated with an elevated risk of SGA comparing middle vs. lowest (RR, 2.34; 95% CI: 1.02, 5.35) and highest vs. lowest (RR, 2.47; 95% CI: 1.09, 5.58) exposure groups. Third-trimester blood TCM concentrations were also associated with an increased risk of SGA comparing the second tertile with the first (RR, 2.61; 95% CI: 1.15, 5.92). We found that maternal blood TCM concentrations were significantly higher for SGA compared with non-SGA births across the period from 23 to 34 wk gestation. Other blood and urinary DBP biomarkers examined were unrelated to SGA, LBW, or preterm birth.

CONCLUSION

Blood TCM concentrations in mid to late pregnancy were associated with an increased risk of SGA, whereas other biomarkers of DBPs examined across pregnancy were not associated with birth outcomes. https://doi.org/10.1289/EHP7195.

Effects of Klotho supplementation on hyperoxia-induced renal injury in a rodent model of postnatal nephrogenesis

BACKGROUND

Hyperoxia (HO) causes kidney injury in preterm infants; however, whether these effects are modifiable is unknown. We hypothesized that administration of exogenous soluble Klotho, a kidney-derived antioxidant, would attenuate HO-induced kidney injury during postnatal nephrogenesis in rats.

METHODS

Sprague Dawley neonatal rats assigned to normoxia (21% O₂) or HO (85% O₂) groups from postnatal day (P) 1 to 21 were randomly assigned to receive alternate day intraperitoneal injections of recombinant Klotho or placebo for 3 weeks. They were recovered in normoxia for an additional 3 weeks and sacrificed at 6 weeks. Renal artery resistance and pulsatility indices, tubular injury scores, glomerular area, and renal antioxidant capacity were assessed.

RESULTS

Rodents exposed to HO during postnatal nephrogenesis had reduced kidney Klotho expression, glomerulomegaly, and higher tubular injury scores. Exogenous Klotho administration improved renal perfusion as indicated by decreases in both resistance and pulsatility indices and increased antioxidant enzyme expression.

CONCLUSIONS

HO exposure during postnatal nephrogenesis in rodents results in a decline in kidney Klotho expression, decreased renal perfusion, enlarged glomerular size, and tubular injury. The exogenous administration of Klotho attenuated HO-induced kidney injury and augmented antioxidant capacity.

Artificial placenta and womb technology: Past, current, and future challenges towards clinical translation

Extreme prematurity remains a major cause of neonatal mortality and severe long-term morbidity. Current neonatal care is associated with significant morbidity due to iatrogenic injury and developmental immaturity of extreme premature infants. A more physiologic approach, replacing placental function and providing a womb-like environment, is the foundational principle of artificial placenta (AP) and womb (AW) technology. The concept has been studied during the past 60 years with limited success. However, recent technological advancements and a greater emphasis on mimicking utero-placental physiology have improved the success of experimental models, bringing the technology closer to clinical translation. Here, we review the rationale for and history of AP and AW technology, discuss the challenges that needed to be overcome, and compare recent successful models. We conclude by outlining some remaining challenges to be addressed on the path towards clinical translation and opportunities for future research.

The Epidemiology and Management of Pediatric AKI in Asia

Because of the lack of early recognition and referral, the incidence of pediatric acute kidney injury (AKI) in Asia still is underestimated. Although each diagnostic criteria has its own merits, the Kidney Disease Improving Global Outcomes classification now is widely accepted. In Asia, the spectrum of pediatric AKI is wide-ranging, from pediatric AKI in highly sophisticated tertiary-care pediatric intensive care units in resource-rich regions due to advanced procedures such as transplantation, cardiac surgery, and other hospital-acquired causes, to primary care preventable causes, such as infectious diseases, snakebite, and so forth in rural parts of the developing world. The development and application of novel biomarkers, concepts such as the Renal Angina Index and advanced renal replacement therapy have revolutionized the era of treating AKI, but the cost and feasibility are the key determinants, especially in rural areas. In view of availability and expenses, peritoneal dialysis should be the first choice in less-developed areas, however, because of various barriers, it still needs more effort. Effective educational steps to both medical carers and families are needed urgently.