The interplay of mutagenesis and ecDNA shapes urothelial cancer evolution.

Advanced urothelial cancer is a frequently lethal disease characterized by marked genetic heterogeneity1. In this study, we investigated the evolution of genomic signatures caused by endogenous and external mutagenic processes and their interplay with complex structural variants (SVs). We superimposed mutational signatures and phylogenetic analyses of matched serial tumours from patients with urothelial cancer to define the evolutionary dynamics of these processes. We show that APOBEC3-induced mutations are clonal and early, whereas chemotherapy induces mutational bursts of hundreds of late subclonal mutations. Using a genome graph computational tool2, we observed frequent high copy-number circular amplicons characteristic of extrachromosomal DNA (ecDNA)-forming SVs. We characterized the distinct temporal patterns of APOBEC3-induced and chemotherapy-induced mutations within ecDNA-forming SVs, gaining new insights into the timing of these mutagenic processes relative to ecDNA biogenesis. We discovered that most CCND1 amplifications in urothelial cancer arise within circular ecDNA-forming SVs. ecDNA-forming SVs persisted and increased in complexity, incorporating additional DNA segments and contributing to the evolution of treatment resistance. Oxford Nanopore Technologies long-read whole-genome sequencing followed by de novo assembly mapped out CCND1 ecDNA structure. Experimental modelling of CCND1 ecDNA confirmed its role as a driver of treatment resistance. Our findings define fundamental mechanisms that drive urothelial cancer evolution and have important therapeutic implications.

Ultrasensitive plasma-based monitoring of tumor burden using machine-learning-guided signal enrichment.

In solid tumor oncology, circulating tumor DNA (ctDNA) is poised to transform care through accurate assessment of minimal residual disease (MRD) and therapeutic response monitoring. To overcome the sparsity of ctDNA fragments in low tumor fraction (TF) settings and increase MRD sensitivity, we previously leveraged genome-wide mutational integration through plasma whole-genome sequencing (WGS). Here we now introduce MRD-EDGE, a machine-learning-guided WGS ctDNA single-nucleotide variant (SNV) and copy-number variant (CNV) detection platform designed to increase signal enrichment. MRD-EDGESNV uses deep learning and a ctDNA-specific feature space to increase SNV signal-to-noise enrichment in WGS by ~300× compared to previous WGS error suppression. MRD-EDGECNV also reduces the degree of aneuploidy needed for ultrasensitive CNV detection through WGS from 1 Gb to 200 Mb, vastly expanding its applicability within solid tumors. We harness the improved performance to identify MRD following surgery in multiple cancer types, track changes in TF in response to neoadjuvant immunotherapy in lung cancer and demonstrate ctDNA shedding in precancerous colorectal adenomas. Finally, the radical signal-to-noise enrichment in MRD-EDGESNV enables plasma-only (non-tumor-informed) disease monitoring in advanced melanoma and lung cancer, yielding clinically informative TF monitoring for patients on immune-checkpoint inhibition.

Childhood cancer mutagenesis caused by transposase-derived PGBD5.

Genomic rearrangements are a hallmark of most childhood tumors, including medulloblastoma, one of the most common brain tumors in children, but their causes remain largely unknown. Here, we show that PiggyBac transposable element derived 5 (Pgbd5) promotes tumor development in multiple developmentally accurate mouse models of Sonic Hedgehog (SHH) medulloblastoma. Most Pgbd5-deficient mice do not develop tumors, while maintaining normal cerebellar development. Ectopic activation of SHH signaling is sufficient to enforce cerebellar granule cell progenitor-like cell states, which exhibit Pgbd5-dependent expression of distinct DNA repair and neurodevelopmental factors. Mouse medulloblastomas expressing Pgbd5 have increased numbers of somatic structural DNA rearrangements, some of which carry PGBD5-specific sequences at their breakpoints. Similar sequence breakpoints recurrently affect somatic DNA rearrangements of known tumor suppressors and oncogenes in medulloblastomas in 329 children. This identifies PGBD5 as a medulloblastoma mutator and provides a genetic mechanism for the generation of oncogenic DNA rearrangements in childhood cancer.

Evolution of structural rearrangements in prostate cancer intracranial metastases.

Intracranial metastases in prostate cancer are uncommon but clinically aggressive. A detailed molecular characterization of prostate cancer intracranial metastases would improve our understanding of their pathogenesis and the search for new treatment strategies. We evaluated the clinical and molecular characteristics of 36 patients with metastatic prostate cancer to either the dura or brain parenchyma. We performed whole genome sequencing (WGS) of 10 intracranial prostate cancer metastases, as well as WGS of primary prostate tumors from men who later developed metastatic disease (n = 6) and nonbrain prostate cancer metastases (n = 36). This first whole genome sequencing study of prostate intracranial metastases led to several new insights. First, there was a higher diversity of complex structural alterations in prostate cancer intracranial metastases compared to primary tumor tissues. Chromothripsis and chromoplexy events seemed to dominate, yet there were few enrichments of specific categories of structural variants compared with non-brain metastases. Second, aberrations involving the AR gene, including AR enhancer gain were observed in 7/10 (70%) of intracranial metastases, as well as recurrent loss of function aberrations involving TP53 in 8/10 (80%), RB1 in 2/10 (20%), BRCA2 in 2/10 (20%), and activation of the PI3K/AKT/PTEN pathway in 8/10 (80%). These alterations were frequently present in tumor tissues from other sites of disease obtained concurrently or sequentially from the same individuals. Third, clonality analysis points to genomic factors and evolutionary bottlenecks that contribute to metastatic spread in patients with prostate cancer. These results describe the aggressive molecular features underlying intracranial metastasis that may inform future diagnostic and treatment approaches.

Epidemiology of cerebral venous sinus thrombosis and cerebral venous sinus thrombosis with thrombocytopenia in the United States, 2018 and 2019.

Background: Population-based data about cerebral venous sinus thrombosis (CVST) are limited. Objectives: To investigate the epidemiology of CVST in the United States. Patients/Methods: Three administrative data systems were analyzed: the 2018 Healthcare Cost and Utilization Project National Inpatient Sample (NIS) the 2019 IBM MarketScan Commercial and Medicare Supplemental Claims Database, and the 2019 IBM MarketScan Multi-state Medicaid Database. CVST, thrombocytopenia, and numerous comorbidities were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification codes. Incidence rates of CVST and CVST with thrombocytopenia were estimated (per 100,000 total US population [NIS] and per 100,000 population aged 0 to 64 years covered by relevant contributing health plans [MarketScan samples]). Comorbidity prevalence was estimated among CVST cases versus total inpatients in the NIS sample. Recent pregnancy prevalence was estimated for the Commercial sample. Results: Incidence rates of CVST in NIS, Commercial, and Medicaid samples were 2.85, 2.45, and 3.16, respectively. Incidence rates of CVST with thrombocytopenia were 0.21, 0.22, and 0.16, respectively. In all samples, CVST incidence increased with age; however, peak incidence was reached at younger ages in females than males. Compared with the general inpatient population, persons with CVST had higher prevalences of hemorrhagic stroke, ischemic stroke, other venous thromboembolism (VTE), central nervous system infection, head or neck infection, prior VTE, thrombophilia, malignancy, head injury, hemorrhagic disorder, and connective tissue disorders. Women aged 18 to 49 years with CVST had a higher pregnancy prevalence than the same-aged general population. Conclusions: Our findings provide recent and comprehensive data on the epidemiology of CVST and CVST with thrombocytopenia.

Failure to Detect Mutations in U2AF1 due to Changes in the GRCh38 Reference Sequence.

The U2AF1 gene is a core part of mRNA splicing machinery and frequently contains somatic mutations that contribute to oncogenesis in myelodysplastic syndrome, acute myeloid leukemia, and other cancers. A change introduced in the GRCh38 version of the human reference build prevents detection of mutations in this gene, and others, by variant calling pipelines. This study describes the problem in detail and shows that a modified GRCh38 reference build with unchanged coordinates can be used to ameliorate the issue.

RP-REP Ribosomal Profiling Reports: an open-source cloud-enabled framework for reproducible ribosomal profiling data processing, analysis, and result reporting.

Ribosomal profiling is an emerging experimental technology to measure protein synthesis by sequencing short mRNA fragments undergoing translation in ribosomes. Applied on the genome wide scale, this is a powerful tool to profile global protein synthesis within cell populations of interest. Such information can be utilized for biomarker discovery and detection of treatment-responsive genes. However, analysis of ribosomal profiling data requires careful preprocessing to reduce the impact of artifacts and dedicated statistical methods for visualizing and modeling the high-dimensional discrete read count data. Here we present Ribosomal Profiling Reports (RP-REP), a new open-source cloud-enabled software that allows users to execute start-to-end gene-level ribosomal profiling and RNA-Seq analysis on a pre-configured Amazon Virtual Machine Image (AMI) hosted on AWS or on the user's own Ubuntu Linux server. The software works with FASTQ files stored locally, on AWS S3, or at the Sequence Read Archive (SRA). RP-REP automatically executes a series of customizable steps including filtering of contaminant RNA, enrichment of true ribosomal footprints, reference alignment and gene translation quantification, gene body coverage, CRAM compression, reference alignment QC, data normalization, multivariate data visualization, identification of differentially translated genes, and generation of heatmaps, co-translated gene clusters, enriched pathways, and other custom visualizations. RP-REP provides functionality to contrast RNA-SEQ and ribosomal profiling results, and calculates translational efficiency per gene. The software outputs a PDF report and publication-ready table and figure files. As a use case, we provide RP-REP results for a dengue virus study that tested cytosol and endoplasmic reticulum cellular fractions of human Huh7 cells pre-infection and at 6 h, 12 h, 24 h, and 40 h post-infection. Case study results, Ubuntu installation scripts, and the most recent RP-REP source code are accessible at GitHub. The cloud-ready AMI is available at AWS (AMI ID: RPREP RSEQREP (Ribosome Profiling and RNA-Seq Reports) v2.1 (ami-00b92f52d763145d3)).

Comparative plaque removal efficacy of a new children's powered toothbrush and a manual toothbrush: Randomized, single use clinical study.

PURPOSE: To compare the plaque removal efficacy of a new children's powered toothbrush to a children's manual toothbrush. METHODS: 55 subjects aged 5-8 years old, who met entry criteria, participated in this single-center, two-cell, examiner-blind, randomized, crossover, single use clinical study. Subjects brushed at home with their first assigned toothbrush and fluoride toothpaste, under supervision of a parent or legal guardian, at least once daily for 2 minutes during a 1-week acclimation period. After refraining from oral hygiene for 12-16 hours, and from eating and drinking for 4 hours, subjects returned to the clinical site where they were assessed for plaque using the Rustogi Modified Navy Plaque Index (RMNPI). Subjects then brushed their teeth with their assigned toothbrush and toothpaste for 2 minutes and plaque levels were reassessed. Subjects were then given their second assigned toothbrush and the acclimation period and clinical site visit were repeated. Safety-in-use was also assessed during each clinic visit. Differences between pre-and post-brushing scores were analyzed for each toothbrush and between toothbrush groups for whole mouth plaque and 12 subset sites using baseline adjusted ANCOVA. RESULTS: Both toothbrushes significantly (P< 0.0001) reduced whole mouth and 12 subset site plaque scores from the pre-brushing baseline. Between treatment comparisons showed that use of the powered toothbrush resulted in statistically significant reductions in whole mouth plaque (55%, P< 0.0001) and in 12 subset site scores (40-208%) compared to the manual brush. This clinical study showed that brushing with a new children's powered toothbrush was safe and significantly more effective than brushing with a manual toothbrush in reducing whole mouth plaque scores, as well as plaque scores at a range of subset sites in the mouth. CLINICAL SIGNIFICANCE: This new powered toothbrush may enable children to safely achieve significant and meaningful improvements in oral hygiene compared to brushing with a manual toothbrush.

The effects of two baking-soda toothpastes in enhancing mechanical plaque removal and improving gingival health: A 6-month randomized clinical study.

PURPOSE: To compare the effectiveness in reducing plaque and gingivitis of two fluoride toothpastes containing baking soda (35% and 20%) with a fluoride toothpaste control. METHODS: 319 subjects, who met entry criteria, participated in this single-center, three-cell, double-blind, randomized, parallel-group clinical study. Gingival Index (MGI), Gingival Bleeding Index (GBI), and Plaque Index (PI) were assessed at baseline, and after 6 weeks, 3 and 6 months. RESULTS: All three toothpastes significantly (P< 0.0001) reduced MGI, GBI, and PI versus baseline, and the two baking soda toothpastes significantly (P< 0.0001) reduced MGI, GBI, and PI compared to the fluoride control, at all three time points. After 6 months use, the 35% and 20% baking soda toothpastes had reduced MGI, GBI and PI by 15.0%, 46.9%, and 18.3%, and 9.4%, 25.9%, and 12.4%, respectively, compared to the control. In addition, the 35% baking soda toothpaste had reduced (P≤ 0.0005) MGI, GBI, and PI by 6.2%, 28.4%, and 6.8%, respectively, compared to the 20% baking soda toothpaste. This clinical study showed that brushing with fluoride toothpastes containing baking soda at 35% and 20% reduces plaque, gingival inflammation and bleeding more effectively than regular fluoride toothpaste. Further, it showed that 35% baking soda toothpaste was more effective in reducing these parameters than 20% baking soda toothpaste. CLINICAL SIGNIFICANCE: Fluoride toothpastes containing 20% or more baking soda can provide significant and meaningful gingival health benefits when used regularly as an adjunct to tooth brushing.

Enhanced plaque removal to improve gingival health: 3-month randomized clinical study of the effects of baking soda toothpaste on plaque and gingivitis.

PURPOSE: To compare the effectiveness in reducing plaque and gingivitis of a fluoride toothpaste with 20% baking soda and a fluoride toothpaste control. METHODS: 159 subjects, who met the entry criteria, participated in this single-center, double-blind, randomized, parallel-group clinical study. Gingival Index (MGI), Gingival Bleeding Index (GBI), and Plaque Index (PI) were assessed after 4, 8, and 12 weeks use of the assigned test or control toothpaste. After 12 weeks, participants resumed 4 weeks of their customary oral hygiene after which they were re-evaluated using the same measures. RESULTS: Both toothpastes statistically significantly reduced MGI, GBI, and PI versus baseline at all-time points. Brushing with the 20% baking soda toothpaste statistically significantly reduced MGI, PI, and GBI compared to the control toothpaste at all time points. After 12 weeks, the reductions in MGI, PI, and GBI were 12.6%, 9.6%, and 44.2%, respectively. After the 4-week customary oral hygiene period, the benefits of the study period had begun to diminish, but statistically significant reductions in MGI and GBI for the test versus control were still evident. This 3-month clinical study shows that brushing with fluoride toothpaste containing 20% baking soda reduces dental plaque and concurrently reduces gingival inflammation and bleeding compared to toothpaste with fluoride alone. CLINICAL SIGNIFICANCE: Fluoride toothpaste with 20% baking soda has the potential to offer multiple oral health benefits when used as an adjunct to regular tooth brushing and, therefore, may be confidently recommended to patients.

Transcriptomic and Metabolic Responses to a Live-Attenuated Francisella tularensis Vaccine.

The immune response to live-attenuated Francisella tularensis vaccine and its host evasion mechanisms are incompletely understood. Using RNA-Seq and LC-MS on samples collected pre-vaccination and at days 1, 2, 7, and 14 post-vaccination, we identified differentially expressed genes in PBMCs, metabolites in serum, enriched pathways, and metabolites that correlated with T cell and B cell responses, or gene expression modules. While an early activation of interferon α/ß signaling was observed, several innate immune signaling pathways including TLR, TNF, NF-κB, and NOD-like receptor signaling and key inflammatory cytokines such as Il-1α, Il-1ß, and TNF typically activated following infection were suppressed. The NF-κB pathway was the most impacted and the likely route of attack. Plasma cells, immunoglobulin, and B cell signatures were evident by day 7. MHC I antigen presentation was more actively up-regulated first followed by MHC II which coincided with the emergence of humoral immune signatures. Metabolomics analysis showed that glycolysis and TCA cycle-related metabolites were perturbed including a decline in pyruvate. Correlation networks that provide hypotheses on the interplay between changes in innate immune, T cell, and B cell gene expression signatures and metabolites are provided. Results demonstrate the utility of transcriptomics and metabolomics for better understanding molecular mechanisms of vaccine response and potential host-pathogen interactions.

Flagellin adjuvanted F1/V subunit plague vaccine induces T cell and functional antibody responses with unique gene signatures.

Yersinia pestis, the cause of plague, could be weaponized. Unfortunately, development of new vaccines is limited by lack of correlates of protection. We used pre- and post-vaccination sera and peripheral blood mononuclear cells from a flagellin adjuvanted F1/V vaccine trial to evaluate for protective markers. Here, we report for the first time in humans that inverse caspase-3 levels, which are measures of protective antibody, significantly increased by 29% and 75% on days 14 and 28 post-second vaccination, respectively. In addition, there were significant increases in T-cell responses on day 28 post-second vaccination. The strongest positive and negative correlations between protective antibody levels and gene expression signatures were identified for IFNG and ENSG00000225107 genes, respectively. Flagellin/F1/V subunit vaccine induced macrophage-protective antibody and significant CD4+ T-cell responses. Several genes associated with these responses were identified that could serve as potential correlates of protection.

Vitamin C Bioequivalence from Gummy and Caplet Sources in Healthy Adults: A Randomized-Controlled Trial.

Background: The efficacy of Vitamin C (L-ascorbic acid) supplementation can be assessed by uptake into the blood and retention in leukocytes. Vitafusion® Power C gummy is an alternative vitamin C source which may exhibit similar bioavailability to comparator caplets.Objective: The objective of this study was to evaluate the bioequivalence of vitamin C from a vitafusion® Power C gummy formulation and a comparator caplet in healthy adults.Methods: Thirty healthy men and women, 34.0 ± 11.4 years of age and Body Mass Index (BMI) 24.5 ± 3.6 kg/m2 completed the randomized examiner-blind, comparator controlled, cross-over trial with two sequences: gummy (1000 mg) to caplet (1000 mg) or caplet to gummy. Intake of foods fortified with Vitamin C was restricted 7 days prior to each dosing. Blood samples were collected pre-dose and at 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 h post-dose for plasma and leukocytes; and urine was collected pre-dose and between 0-2, 2-4, 4-8, 8-12 and 12-24 h post-dose for L-ascorbic acid analysis.Results: Vitafusion® Power C gummy and comparator caplet demonstrated similar plasma absorption profiles as there were no significant differences in plasma L-ascorbic acid total Area Under the Curve (AUC)0-24h, and Tmax between gummy and caplet. The caplet did elicit a significantly higher Cmax than the gummy (p < 0.05), however, the difference was numerically small. Leukocyte L-ascorbic acid total AUC0-24h and Cmax were not significantly different between gummy and caplet, however Tmax of the gummy group was significantly longer (p = 0.012). Urinary L-ascorbic acid levels were also not significantly different between gummy and caplet. There were no serious adverse events and safety parameters remained within normal clinical range for both products.Conclusion: Vitafusion® Power C gummy exhibited similar Vitamin C absorption and bioavailability to a comparator caplet in healthy adults and were considered bioequivalent.

Systems Vaccinology for a Live Attenuated Tularemia Vaccine Reveals Unique Transcriptional Signatures That Predict Humoral and Cellular Immune Responses.

Background: Tularemia is a potential biological weapon due to its high infectivity and ease of dissemination. This study aimed to characterize the innate and adaptive responses induced by two different lots of a live attenuated tularemia vaccine and compare them to other well-characterized viral vaccine immune responses. Methods: Microarray analyses were performed on human peripheral blood mononuclear cells (PBMCs) to determine changes in transcriptional activity that correlated with changes detected by cellular phenotyping, cytokine signaling, and serological assays. Transcriptional profiles after tularemia vaccination were compared with yellow fever [YF-17D], inactivated [TIV], and live attenuated [LAIV] influenza. Results: Tularemia vaccine lots produced strong innate immune responses by Day 2 after vaccination, with an increase in monocytes, NK cells, and cytokine signaling. T cell responses peaked at Day 14. Changes in gene expression, including upregulation of STAT1, GBP1, and IFIT2, predicted tularemia-specific antibody responses. Changes in CCL20 expression positively correlated with peak CD8+ T cell responses, but negatively correlated with peak CD4+ T cell activation. Tularemia vaccines elicited gene expression signatures similar to other replicating vaccines, inducing early upregulation of interferon-inducible genes. Conclusions: A systems vaccinology approach identified that tularemia vaccines induce a strong innate immune response early after vaccination, similar to the response seen after well-studied viral vaccines, and produce unique transcriptional signatures that are strongly correlated to the induction of T cell and antibody responses.

Fast design of arbitrary length loops in proteins using InteractiveRosetta.

BACKGROUND: With increasing interest in ab initio protein design, there is a desire to be able to fully explore the design space of insertions and deletions. Nature inserts and deletes residues to optimize energy and function, but allowing variable length indels in the context of an interactive protein design session presents challenges with regard to speed and accuracy. RESULTS: Here we present a new module (INDEL) for InteractiveRosetta which allows the user to specify a range of lengths for a desired indel, and which returns a set of low energy backbones in a matter of seconds. To make the loop search fast, loop anchor points are geometrically hashed using C α-C α and C ß-C ß distances, and the hash is mapped to start and end points in a pre-compiled random access file of non-redundant, protein backbone coordinates. Loops with superposable anchors are filtered for collisions and returned to InteractiveRosetta as poly-alanine for display and selective incorporation into the design template. Sidechains can then be added using RosettaDesign tools. CONCLUSIONS: INDEL was able to find viable loops in 100% of 500 attempts for all lengths from 3 to 20 residues. INDEL has been applied to the task of designing a domain-swapping loop for T7-endonuclease I, changing its specificity from Holliday junctions to paranemic crossover (PX) DNA.

Females with FVIII and FIX deficiency have reduced joint range of motion.

Little is known about rates of joint bleeding among females with FVIII/FIX deficiency or hemophilia carriers. In a cross-sectional study, we tested the hypothesis that females with FVIII or FIX deficiency enrolled in the Universal Data Collection (UDC) project had a reduced mean overall joint range of motion (ROM) compared with historic controls from the Normal Joint Study. Demographics, clinical characteristics, and joint ROM measurements on 303 females without a bleeding disorder and 148 females with FVIII and FIX deficiency, respectively, between the ages of 2-69 years and a body mass index (BMI) ≤ 35 were compared. Multivariate linear regression was performed with the overall joint ROM (sum of the right and left ROM measurements of five joints) as the dependent variable and FVIII or FIX activity as the independent variable adjusting for age, race, BMI, and number of joint bleeds reported over the last 6 months. As FVIII and FIX activity decreased, the mean overall joint ROM became reduced and in most cases was significantly lower than that of the controls regardless of age and clinical hemophilia severity. Further investigation of reduced joint ROM as evidence of subclinical joint bleeding in females with FVIII and FIX deficiency is warranted.

Pure autonomic failure.

A 1925 report by Bradbury and Eggleston first described patients with extreme orthostatic hypotension and a low, steady heart rate. Evidence accumulated over the next two decades that patients with orthostatic hypotension include those with pure autonomic failure (PAF), characterized by isolated peripheral autonomic dysfunction and decreased norepinephrine synthesis; multiple system atrophy (MSA) with symptoms of a central Parkinson-like syndrome and normal resting plasma norepinephrine; and Parkinson's disease (PD), with lesions in postganglionic noradrenergic neurons and signs of autonomic dysfunction. All three disorders are classified as α-synucleinopathies. Insoluble deposits of α-synuclein are found in glia in MSA, whereas they take the form of neuronal cytoplasmic inclusions called Lewy bodies in PAF and PD. The exact relationship between α-synuclein deposits and the pathology remains undetermined. PAF occurs sporadically, and progresses slowly with a relatively good prognosis. However, it has been proposed that some cases of PAF may develop a central neurodegenerative disorder. Differentiation between PAF, MSA, and PD with autonomic failure can be facilitated by a number of biochemical and functional tests and by imaging studies. Cardiac sympathetic innervation is generally intact in MSA but decreased or absent in Parkinson's disease with autonomic failure and PAF. Treatment of PAF is directed at relieving symptoms with nonpharmacological interventions and with medications producing volume expansion and vasoconstriction. Future studies should focus on determining the factors that lead to central rather than solely peripheral neurodegeneration.

Trends in venous thromboembolism among pregnancy-related hospitalizations, United States, 1994-2009.

OBJECTIVE: The purpose of this study was to evaluate national trends in the rate of pregnancy-related hospitalizations for venous thromboembolism (VTE) from 1994-2009 and to estimate the prevalence of comorbid conditions among these hospitalizations. STUDY DESIGN: An estimated 64,413,973 pregnancy-related hospitalizations among women 15-44 years old were identified in the 1994-2009 Nationwide Inpatient Sample. Trends in VTE-associated pregnancy hospitalizations were evaluated with the use of variance-weighted least squares regression. Chi-square tests were used to assess changes in prevalence of demographics and comorbid conditions, and multivariable logistic regression was used to evaluate the likelihood of VTE during the study period after adjustment for comorbid conditions. Antepartum, delivery, and postpartum hospitalizations were evaluated separately and reported in 4-year increments. RESULTS: From 1994-2009, there was a 14% increase in the rate of overall VTE-associated pregnancy hospitalizations; antepartum and postpartum hospitalizations with VTE increased by 17% and 47%, respectively. Between 1994-1997 and 2006-2009, the prevalence of hypertension and obesity doubled among all VTE-associated pregnancy hospitalizations; significant increases in diabetes mellitus and heart disease were also noted. A temporal increase in the likelihood of a VTE diagnosis in pregnancy was observed for antepartum hospitalizations from 2006-2009 when compared with 1994-1997 (adjusted odds ratio, 1.62; 95% confidence interval, 1.48-1.78). CONCLUSION: There has been an upward trend in VTE-associated pregnancy hospitalizations from 1994-2009 with concomitant increases in comorbid conditions. Clinicians should have a heightened awareness of the risk of VTE among pregnant women, particularly among those with comorbid conditions, and should have a low threshold for evaluation in women with symptoms or signs of VTE.