Development of a Predictive Nomogram for Sepsis in Patients with Urolithiasis-Related Obstructive Pyelonephritis.

Background and Objectives: In patients with urolithiasis-related obstructive pyelonephritis (UROP), sepsis represents a critical and concerning complication that can substantially increase the mortality rate. This study aimed to identify the risk factors for sepsis in UROP patients and to develop a predictive nomogram model. Materials and Methods: We analyzed data from 148 patients who met the UROP criteria and were admitted to Chang Gung Memorial Hospital between 1 January 2016 and 31 December 2021. The primary outcome evaluated was the incidence of sepsis, as defined by the most recent Sepsis-3 guidelines. To identify potential risk factors for sepsis, we employed the Least Absolute Shrinkage and Selection Operator (LASSO) regression technique. Subsequently, we utilized multivariable logistic regression to construct the predictive model. Results: There was a total of 102 non-sepsis cases and 46 sepsis cases. Risk factors for sepsis in multivariable analysis were a history of diabetes mellitus (DM) (OR = 4.24, p = 0.007), shock index (SI) (×10-1) (OR = 1.55, p < 0.001), C-reactive protein (CRP) (mg/dL) (OR = 1.08, p = 0.005), and neutrophil to lymphocyte ratio (NLR) (×10) (OR = 1.58, p = 0.007). The nomogram exhibited an area under the receiver operating characteristic curve of 0.890 (95% CI 0.830-0.949). Conclusions: Our study demonstrated that patients with UROP who have DM, higher SI, higher NLR, and elevated CRP levels are significantly more likely to develop sepsis. These insights may aid in risk stratification, and it is imperative that clinicians promptly initiate treatment for those identified as high risk.

Insulin receptor orchestrates kidney antibacterial defenses.

Urinary tract infection (UTI) commonly afflicts people with diabetes. This augmented infection risk is partly due to deregulated insulin receptor (IR) signaling in the kidney collecting duct. The collecting duct is composed of intercalated cells (ICs) and principal cells (PCs). Evidence suggests that ICs contribute to UTI defenses. Here, we interrogate how IR deletion in ICs impacts antibacterial defenses against uropathogenic Escherichia coli. We also explore how IR deletion affects immune responses in neighboring PCs with intact IR expression. To accomplish this objective, we profile the transcriptomes of IC and PC populations enriched from kidneys of wild-type and IC-specific IR knock-out mice that have increased UTI susceptibility. Transcriptomic analysis demonstrates that IR deletion suppresses IC-integrated stress responses and innate immune defenses. To define how IR shapes these immune defenses, we employ murine and human kidney cultures. When challenged with bacteria, murine ICs and human kidney cells with deregulated IR signaling cannot engage central components of the integrated stress response-including activating transcriptional factor 4 (ATF4). Silencing ATF4 impairs NFkB activation and promotes infection. In turn, NFkB silencing augments infection and suppresses antimicrobial peptide expression. In diabetic mice and people with diabetes, collecting duct cells show reduced IR expression, impaired integrated stress response engagement, and compromised immunity. Collectively, these translational data illustrate how IR orchestrates collecting duct antibacterial responses and the communication between ICs and PCs.

Label-free investigation of infected acute pyelonephritis tissue by FTIR microspectroscopy with unsupervised and supervised analytical methods.

Acute pyelonephritis (AP) is a severe urinary tract infection (UTI) syndrome with a large population of patients worldwide. Current approaches to confirming AP are limited to urinalysis, radiological imaging methods and histological assessment. Fourier transform infrared (FTIR) microspectroscopy is a promising label-free modality that can offer information about both morphological and molecular pathologic alterations from biological tissues. Here, FTIR microspectroscopy serves to investigate renal biological histology of a rat model with AP and classify normal cortex, normal medulla and infected acute pyelonephritis tissues. The spectra were experimentally collected by FTIR with an infrared Globar source through raster scanning procedure. Unsupervised analysis methods, including integrating, clustering and principal component analysis (PCA) were performed on such spectra data to form infrared histological maps of entire kidney section. In comparison to Hematoxylin & Eosin-stained results of the adjacent tissue sections, these infrared maps were proved to enable the differentiation of the renal tissue types. The results of both integration and clustering indicated that the concentration of amide II decreases in the infected acute pyelonephritis tissues, with an increased presence of nucleic acids and lipids. By means of PCA, the infected tissue was linearly separated from normal ones by plotting confident ellipses with the score values of the first and second principal components. Moreover, supervised analysis was performed based on the supported vector machines (SVM). Normal cortex, normal medulla and infected acute pyelonephritis tissues were classified by SVM models with the best accuracy of 96.11% in testing dataset. In addition, these analytical methods were further employed on synchrotron-based FTIR spectra data and successfully form high-resolution infrared histological maps of glomerulus and necrotic cell mass. This work demonstrates that FTIR microspectroscopy will be a powerful manner to investigate AP tissue and differentiate infected tissue from normal tissue in a renal infected model system.

Defining complicated urinary tract infection and route of antibiotics in children presenting to the emergency department: a cohort study using the Melbourne RUPERT clinical score.

OBJECTIVES: Most children with uncomplicated urinary tract infections (UTI) can be managed with oral antibiotics. However, identifying those likely to fail oral and need intravenous antibiotics due to complicating features at presentation is challenging. We aimed to derive, validate and test a score to guide initial antibiotic route. DESIGN: This cohort study enrolled children both prospectively and retrospectively. Patients were divided into two groups based on whether they received intravenous or oral antibiotics after 24 hours, including those who switched between routes. Children diagnosed with confirmed UTI were used to derive then validate the score, comparing complicating clinical features between the two groups. Combinations of significantly differentiating features generated receiver operating characteristic curves and the optimal cut-off for intravenous antibiotic use was selected. SETTING: The emergency department of a tertiary paediatric hospital. PARTICIPANTS: All children aged 3 months-17 years with suspected UTI were eligible, and were included if they fulfilled the diagnostic criteria for UTI. OUTCOME MEASURES: The effectiveness of the derived clinical score to differentiate patients at presentation who had complicated UTI requiring ongoing intravenous antibiotics. RESULTS: There were 1240 patients, of whom 167 children aged 12 months-11 years with confirmed UTI comprised the derivation cohort. The combination of features that performed optimally (area under curve 0.85, 95% CI 0.79 to 0.91) were: rigors, urological abnormality, fever (≥38°C), emesis, recurrent (≥3) UTI, tachycardia: the RUPERT score (1 point each, maximum 6). A score ≥3 accurately classified route of antibiotics after 24 hours for 80% patients (sensitivity 77%, specificity 81%). For the 168 patients in the validation cohort, the score accurately classified 76% (sensitivity 67%, specificity 78%). The score tested well in 'probable' UTI and adolescents, and less well in infants. CONCLUSION: The Melbourne RUPERT score provides the first standardised, easy-to-use score to aid clinicians in deciding route of antibiotics for more complicated UTI in children. It now needs prospective validation.

Increased water intake dilutes protective uromodulin levels in urine and results in increased rates of pyelonephritis in a murine model.

AIM: Urinary tract infections (UTIs) rank among the most prevalent infections in humans, carrying substantial implications for public health. Women experiencing recurrent UTIs are often advised to boost their fluid intake to help eliminate bacteria. In this study, we explored the impact of elevated fluid consumption during UTIs using a mouse model of pyelonephritis. METHODS: UTI was induced in 8-10 w female BALB/cJ-mice by surgically injecting Escherichia coli (O6:K13:H1) into the bladder whereafter mice were randomized to gel food (GF) or regular chow. Immune response and infection severity were determined 24-h post-infection. In vitro bacterial growth (OD600) was determined in urine from mice or from human volunteers. RESULTS: Gel feeding increased urine output (1.40 ± 0.77 µL min-1, p < 0.01) and diluted the urine (668.7 ± 177 mOsmol kg-1, p < 0.0001) compared to controls on regular chow (urine output: 0.34 ± 0.27 µL min-1, osmolality: 1439 ± 473.5 mOsmol kg-1). Mice on GF had a higher risk of pyelonephritis (87.5%) and more severe infections (26.22 ± 9.88 CFU mg-1 tissue) compared to controls (43.75%; 3.87 ± 3.56 CFU mg-1, p < 0.01). Correspondingly, the growth of E. coli was markedly reduced at osmolalities above 1200 mOsmol kg-1 compared to 600 mOsmol kg-1 and GF mice had lower urine levels of uromodulin (13.70 ± 1.89 µg mL-1, p < 0.01) compared to controls (24.65 ± 2.70 µg mL-1). CONCLUSION: Increased water intake and urine flow in mice will markedly increase the risk of pyelonephritis. The increased risk may reflect reduced urine uromodulin combined with optimized growth conditions for E. coli. The study does not immediately support the notion that established UTIs can be eliminated by increased water intake.

Acute Bilateral Pyelonephritis in the Setting of Newly Diagnosed Diabetes Mellitus: A Case Report.

Introduction: Acute pyelonephritis is a bacterial infection that starts in the bladder and ascends to the kidneys, causing inflammation of the renal parenchyma. Women are more likely to get infected compared to men, with diabetics being at higher risk. The pathophysiology of how diabetics are more prone to getting urinary tract infections/pyelonephritis has been studied, particularly the difference between bilateral pyelonephritis and unilateral pyelonephritis. Case Presentation: This case presentation follows a 51-year-old Spanish-speaking woman with a past medical history of prediabetes, bilateral tubal ligation, and perimenopause. She presented to the hospital for abdominal and back pain, fevers, and weakness that she had for a week. An intake of her history and a physical examination led to the initial diagnosis of cystitis, but the imaging drove the authors to the correct diagnosis of acute bilateral pyelonephritis with Escherichia coli growing in the urine. She was then treated with the appropriate antibiotics. During her hospital stay, she was also diagnosed with type 2 diabetes mellitus. Imaging is not usually used to diagnose pyelonephritis, but it is necessary in some cases and can help identify complications. There are multiple case reports about acute pyelonephritis, but there are few that touch on acute bilateral pyelonephritis. Conclusion: We are highlighting this case presentation since it shows how a patient with newly diagnosed diabetes is at more of a risk of developing acute bilateral pyelonephritis. This information is important not only to add to medical knowledge but also to allow physicians to emphasize diabetic control in order to minimize the chance of developing pyelonephritis.

A Diagnostic Dilemma: A Case of Complicated Pneumonia With Pyelonephritis and Subclinical Myocarditis.

A 41-year-old woman presented with a 3.5-month history of fever, weakness, productive cough, and burning micturition along with generalized weakness and significant weight loss. Chest X-ray revealed bilateral infiltrates and bilateral pleural effusion, and the workup suggested community-acquired pneumonia (CAP). However, the course was complicated by persistent fevers, elevated inflammatory markers, elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), and pelvic fluid collection. Extensive investigations, including bronchoscopy and lung biopsy, failed to identify a specific pathogen. Pulmonary vasculitis and lymphoma were ruled out. Antibiotic and corticosteroid therapy resulted in clinical improvement. While the cause remains unknown, brucellosis and aspergillosis were considered but ruled out with advanced testing. The underlying etiology remains elusive, highlighting the diagnostic challenges in CAP with atypical presentations.

Report on the diagnosis and treatment of 3 cases of emphysematous pyelonephritis with two different outcomes.

Background: Emphysematous pyelonephritis (EPN) is a rare acute severe necrotising infection of the kidneys in clinical practice. It is characterized by the presence of gas in the renal parenchyma, collecting system, or perirenal tissue. The prognosis is poor, with a high nephrectomy rate and a mortality rate of up to 20-40%. Methods: Retrospective analysis of 3 cases of emphysematous pyelonephritis with two different outcomes. Results: Three patients who we described were all female with diabetes mellitus, and their blood sugar was poorly controlled. One patient with the advanced age and poor general health died due to the patient's family choosing to terminate therapy. Two patients underwent surgical procedures achieved an excellent clinical recovery. Both of them underwent percutaneous nephrostomy and perinephric abscess puncture drainage before nephrectomy. Escherichia coli were the microorganisms implicated. Conclusion: EPN is a rare and severe urinary system infection. Computed tomography (CT) and microbiological culture confirmed the diagnosis. Control of diabetes, sensitive antibiotic therapy, fluid resuscitation and prompt surgical intervention are crucial.

A case of endogenous endophthalmitis caused by Escherichia coli septicemia.

Endogenous endophthalmitis is a severe sight-threatening condition that requires urgent intervention. It is a rare complication of Escherichia coli septicemia. We herein report a case of left eye endogenous endophthalmitis with uncontrolled type 2 diabetes mellitus with pyelonephritis associated with Escherichia coli septicemia. Vitrectomy was done along with intravitreal antibiotics and steroids. There was significant improvement in vision after vitrectomy.

Emphysematous Pyelonephritis in a Patient on SGLT2 Inhibitor Therapy: A Rare Clinical Case Report.

Introduction: Emphysematous pyelonephritis is a rare but potentially life-threatening urinary tract infection characterized by the formation of gas in the renal parenchyma, collecting system, and perinephric tissue. The condition typically develops in patients with specific predisposing factors such as diabetes mellitus, congenital or acquired obstructive uropathies, or individuals taking immunosuppressive agents. Rarely can the disease occur in patients with other predisposing factors, such as the use of SGLT2 inhibitors, but this is quite uncommon. The incidence of urinary tract infections associated with their use is still debatable, but cases of emphysematous pyelonephritis associated with SGLT2 inhibitors have been described in medical literature. Case Presentation: We present a rare case of a patient with emphysematous pyelonephritis without classical risk factors for the disease, who was taking an SGLT2 inhibitor. Conclusion: Although the frequency of urinary tract infections following the use of SGLT2 inhibitors is relatively low, their widespread application for treatment of numerous socially significant diseases underscores the necessity for specialists to be aware with all potential risks associated with their use, including the development of severe urinary tract infections.

Xanthogranulomatous Pyelonephritis in Peritoneal Dialysis.

Introduction: Xanthogranulomatous pyelonephritis (XGP) is a rare illness that consists of a destructive chronic inflammatory process of the renal parenchyma associated with recurrent infection and obstructions of the urinary tract. Peritoneal dialysis (PD) is a form of renal replacement therapy used in advanced kidney disease. PD patients demonstrate a systemic inflammatory state, secondary to the increase in uremic toxins, decreased filtration of proinflammatory cytokines, as well as constant exposure to bioincompatible dialysis solutions or a foreign body reaction from the catheter, among other factors, as peritoneal infections. Case Presentation: We present the clinical case of a 74-year-old woman, with a history of recurrent urinary tract infections associated with nephrolithiasis and stage 5D chronic kidney disease, on a PD program. The patient presented a non-specific 3-month state of progressive asthenia, with increased inflammatory parameters in the analytical controls. After presenting multiple negative urine cultures and peritoneal fluid cultures, she was hospitalized to study the constitutional syndrome. The imaging test revealed bilateral staghorn lithiasis with severe dilatation of the right renal pelvis and great cortical thinning. Given the suspicion of XGP, it was decided to perform right renal nephrectomy, which was confirmed after the anatomopathological study. Prior to the intervention, she was transferred to hemodialysis. Over the following months, significant clinical and analytical improvement was observed. Conclusion: The systemic inflammatory state and the risk of infections in PD can mask the diagnosis of XGP in PD patients. There are no reported cases of XGP in patients in PD.

Evaluation of Local Prescribing Patterns and Antimicrobial Resistance in Women With Acute Pyelonephritis Caused by E. coli.

BACKGROUND: Owing to increasing local Escherichia coli resistance and current guidelines for the treatment of acute pyelonephritis (APN) over 14 years old, an evaluation of local prescribing patterns is warranted. OBJECTIVE: The purpose of this study was to evaluate local prescribing patterns and appropriateness of antibiotics in acute uncomplicated APN. METHODS: This is a retrospective cohort study of female patients aged 18 to 89 years diagnosed with APN and positive urine culture growing E. coli. Exclusion criteria included pregnancy, immunocompromised status, and complicated urinary tract infections. Outcomes included antibiotic appropriateness and its effects on hospital admission, hospital length of stay, and 30-day readmission. RESULTS: Between 2017 and 2022, 308 female patients were diagnosed with APN and had positive urine cultures, with 104 seen only in the emergency department (ED) and 109 admitted to the hospital. Patients seen in the ED had a significant increase in E. coli resistance to discharge antibiotics (12.5% vs 2.8%, P = 0.0070). In those patients discharged on antibiotics resistant to E. coli, significantly more patients returned to the ED in 30 days (31.3% vs 10.7%, P = 0.0155). CONCLUSION AND RELEVANCE: Patients seen only in the ED were more likely to have resistant organisms to discharge antibiotics compared with those admitted to the hospital. Patients discharged on antibiotics resistant to E. coli had a 3-fold increase in returning to the ED within 30 days regardless of admitted location. Follow-up of all cultures should be performed, and patients resistant to discharge antibiotics should be contacted and antibiotic regimens changed.

Oral quinolones versus intravenous ß-lactam for the treatment of acute focal bacterial nephritis: a retrospective cohort study.

BACKGROUND: Evidence regarding the best antibiotic regimen and the route of administration to treat acute focal bacterial nephritis (AFBN) is scarce. The aim of the present study was to compare the effectiveness of intravenous (IV) ß-lactam antibiotics versus oral quinolones. METHODS: This is a retrospective single centre study of patients diagnosed with AFBN between January 2017 and December 2018 in Hospital Universitari Vall d'Hebron, Barcelona (Spain). Patients were identified from the diagnostic codifications database. Patients treated with oral quinolones were compared with those treated with IV ß-lactam antibiotics. Therapeutic failure was defined as death, relapse, or evolution to abscess within the first 30 days. RESULTS: A total of 264 patients fulfilled the inclusion criteria. Of those, 103 patients (39%) received oral ciprofloxacin, and 70 (26.5%) IV ß-lactam. The most common isolated microorganism was Escherichia coli (149, 73.8%) followed by Klebsiella pneumoniae (26, 12.9%). Mean duration of treatment was 21.3 days (SD 7.9). There were no statistical differences regarding therapeutic failure between oral quinolones and IV ß-lactam treatment (6.6% vs. 8.7%, p = 0.6). Out of the 66 patients treated with intravenous antibiotics, 4 (6.1%) experienced an episode of phlebitis and 1 patient (1.5%) an episode of catheter-related bacteraemia. CONCLUSIONS: When susceptible, treatment of AFBN with oral quinolones is as effective as IV ß-lactam treatment with fewer adverse events.

Association Between Antibiotic Duration and Recurrence of Urinary Tract Infection in the Neonatal Critical Care Unit.

OBJECTIVES: Urinary tract infection (UTI) is the most common bacterial infection in infants. Current practice guidelines suggest a treatment duration of 7 to 14 days. Suboptimal therapy may increase the risk for recurrent UTIs leading to renal scarring and possibly chronic kidney disease. The primary objective is to evaluate the duration of therapy for UTIs and its association with the incidence of recurrent UTIs in a neonatal intensive care unit (NICU). The secondary objectives are to identify the risk factors and the most common organisms for recurrent UTIs. METHODS: Patients were identified via the diagnosis codes for UTIs and were included if admitted to the NICU and if they received antibiotics prior to hospital discharge. Patients were divided into 2 groups: antibiotic treatment for 7 days or fewer and antibiotic treatment for greater than 7 days. RESULTS: Eighty-six infants were included in the study. Twenty-six patients received antibiotics for 7 days or fewer, and 60 for more than 7 days. In the study, the median birth weight was 977 g and the median gestational age was 27.6 weeks. There was no significant difference in the rate of recurrent UTIs between the 2 groups (p = 0.66). However, in the subgroup analysis, the incidence was higher for patients receiving antibiotic therapy for fewer than 7 days versus 7 days (p = 0.03). CONCLUSION: There was no difference in recurrence of UTI between treatment groups (≤7 days versus >7 days), and recurrence was seen in a higher percentage of patients with a urinary tract anomaly.

The impact of the distal ureteral diameter ratio, bladder volume at onset of vesicoureteral reflux, and/or grade in predictive models of clinical outcomes in children with vesicoureteral reflux.

PURPOSE: Vesicoureteral reflux (VUR) grade has been used as a primary factor in assessing a child's risk of clinical outcomes. Unfortunately, grade has poor inter-observer reliability. We hypothesized that more objective and reliable VCUG parameters including the distal ureteral diameter ratio (UDR) and volume at onset of VUR (Vol) may either augment or replace the current grading system to provide more reliable prediction of clinical outcomes. MATERIALS AND METHODS: Multivariate clinical outcome models were analyzed to assess the impact on predictive accuracy by the addition of voiding cystourethrogram (VCUG) data including grade, UDR, and Vol, alone or in combinations. Clinical variables from retrospective review of 841 children's records included age, gender, presentation, VUR laterality, bowel and bladder dysfunction, history of febrile urinary tract infection (UTI), and number of UTIs. The primary outcomes assessed included VUR resolution or persistence and need for operative intervention. RESULTS: Grade, UDR, and Vol were independent predictors of resolution and operative intervention. Vol increased predictive accuracy in resolution models with grade or UDR alone; however, no significant difference occurred in models with the substitution of grade with UDR. CONCLUSIONS: A more reliable classification system for VUR, with improved predictive accuracy regarding clinical outcomes, may be developed incorporating UDR and Vol. Whether VUR grade can be completely replaced by Vol and UDR measurements requires further evaluation with larger number of patients.

A Rare Case of Emphysematous Pyelonephritis in a Non-diabetic Patient With Staghorn Calculus.

Emphysematous pyelonephritis (EPN) represents a severe and acute infection localized in the renal parenchyma and surrounding perirenal area, typically observed in individuals with predisposing factors such as urinary tract obstruction, diabetes mellitus, or compromised immune function. Here, we present a unique case involving a 23-year-old female patient presenting to the emergency department with complaints of discomfort localized to the right side of her abdomen. Despite the absence of diabetes mellitus, the patient was diagnosed with EPN based on clinical presentation and imaging findings. Prompt and effective management was initiated under the care of the urology department, highlighting the importance of early recognition and intervention in mitigating the potential complications associated with this severe infectious process.

Identification and characterization of a novel α-haemolytic streptococci, Streptococcus parapneumoniae sp. nov., which caused bacteremia with pyelonephritis.

OBJECTIVES: We report a case of bacteremia with pyelonephritis in an adult male with an underlying disease caused by α-hemolytic streptococci. α-Hemolytic streptococci were isolated from blood, but it was challenging to identify its species. This study aimed to characterize the causative bacterium SP4011 and to elucidate its species. METHODS: The whole-genome sequence and biochemical characteristics of SP4011 were determined. Based on the genome sequence, phylogenetic analysis was performed with standard strains of each species of α-hemolytic streptococci. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated. RESULTS: SP4011 showed optochin susceptibility and bile solubility, but did not react with pneumococcal omni antiserum. Phylogenetic analysis of the whole-genome sequence showed that SP4011 clustered with S. pneumoniae and S. pseodopneumoniae and was most closely related to S. pseodopneumoniae. Genomic analysis revealed that ANI and dDDH values between SP4011 and S. pseodopneumoniae were 94.0 % and 56.0 %, respectively, and between SP4011 and S. pneumoniae were 93.3 % and 52.2 %, respectively. Biochemical characteristics also showed differences between SP4011 and S. pseodopneumoniae and between SP4011 and S. pneumoniae. These results indicate that SP4011 is a novel species. CONCLUSION: Our findings indicate that SP4011 is a novel species of the genus Streptococcus. SP4011 has biochemical characteristics similar to S. pneumoniae, making it challenging to differentiate and requiring careful clinical diagnosis. This isolate was proposed to be a novel species, Streptococcus parapneumoniae sp. nov. The strain type is SP4011T (= JCM 36068T = KCTC 21228T).

Antenatal pyelonephritis hospitalisation trends, risk factors and associated adverse outcomes: A retrospective cohort study.

OBJECTIVE: To analyse trends, risk factors and adverse outcomes associated with antenatal pyelonephritis hospitalisations. DESIGN: Retrospective cohort. SETTING: A national sample of US delivery hospitalisations with associated antenatal hospitalisations. POPULATION: US delivery hospitalisations in the Nationwide Readmissions Database from 2010 to 2020. METHODS: Antenatal hospitalisations with a pyelonephritis diagnosis within the 9 months before delivery hospitalisation were analysed. Clinical, demographic and hospital risk factors associated with antenatal pyelonephritis hospitalisations were analysed with unadjusted and adjusted logistic regression models with unadjusted and adjusted odds ratios as measures of effect. Temporal trends in antenatal pyelonephritis hospitalisations were analysed with Joinpoint regression to determine the relative measure of average annual percent change (AAPC). Risk for severe maternal morbidity and sepsis during antenatal pyelonephritis hospitalisations was similarly analysed with Joinpoint regression. RESULTS: Of an estimated 10.2 million delivery hospitalisations, 49 140 (0.48%) had an associated antenatal pyelonephritis hospitalisation. The proportion of deliveries with a preceding antenatal pyelonephritis hospitalisation decreased by 29% from 0.56% in 2010 to 0.40% in 2020 (AAPC -2.9%, 95% CI -4.0% to -1.9%). Antenatal pyelonephritis decreased, but risk for sepsis diagnoses increased during these hospitalisations from 3.7% in 2010 to 18.0% in 2020 (AAPC 17.2%, 95% CI 14.2%-21.1%). Similarly, risk for severe morbidity increased from 2.6% in 2010 to 4.4% in 2020 (AAPC 5.5%, 95% CI 0.8%-10.7%). CONCLUSION: Antenatal pyelonephritis admissions appear to be decreasing in the USA. However, these hospitalisations are associated with a rising risk for sepsis and severe maternal morbidity.