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While high-pressure chemistry has a well-established history, methods to simulate pressure at the single-molecule level have been somewhat lacking. The current work aims at comparing two static models (XP-PCM and GOSTSHYP) to apply isotropic pressure to single molecules, focusing on the equilibrium bond length and electric dipole moment of diatomic molecules. Numerical challenges arising in the potential energy surface using the XP-PCM method were examined, and a pragmatic approach was followed to mitigate these. The definition of the cavity was scrutinized, and two approaches to retrieve the isotropic character that could potentially be lost when using the standard methodology were suggested. Subsequently, equilibrium bond lengths under pressure were evaluated, showing reasonable agreement between GOSTSHYP and XP-PCM, but some discrepancies persist. A Taylor series analysis introduced elsewhere was then applied to rationalize the observed trends in terms of the bond surface. Finally, the dipole moment was shown to be highly sensitive to the cavity definition, and qualitative agreement necessitates the use of our adapted procedure.

Currently, real-world data on doravirine are scarce. In a national prospective cohort, we assessed the effectiveness and tolerability of switching to doravirine-based antiretroviral therapy (ART) in people with HIV.

The human intestinal mucus layer protects against pathogenic microorganisms and harmful substances, whereas it also provides an important colonization niche for mutualistic microbes. The main functional components of mucus are heavily glycosylated proteins, called mucins. Mucins can be cleaved and utilized by intestinal microbes. The mechanisms between intestinal microbes and the regulation of mucin glycosylation are still poorly understood. In this study, in vitromucus was produced by HT29-MTX-E12 cells under Semi-Wet interface with Mechanical Stimulation. Cells were exposed to pasteurized nonpathogenic bacteria Akkermansia muciniphila, Ruminococcus gnavus, and Bacteroides fragilisto evaluate influence on glycosylation patterns. Following an optimized protocol, O- and N-glycans were efficiently and reproducibly released, identified, and semiquantified using MALDI-TOF-MS and PGC-LC-MS/MS. Exposure of cells to bacteria demonstrated increased diversity of sialylated O-glycans and increased abundance of high mannose N-glycans in in vitroproduced mucus. Furthermore, changes in glycan ratios were observed. It is speculated that bacterial components interact with the enzymatic processes in glycan production and that pasteurized bacteria influence glycosyltransferases or genes involved. These results highlight the influence of pasteurized bacteria on glycosylation patterns, stress the intrinsic relationship between glycosylation and microbiota, and show the potential of using in vitroproduced mucus to study glycosylation behavior.

Early changes in circulating tumor DNA (ctDNA) levels during immunotherapy strongly associate with therapy response and survival of patients with advanced urothelial cancer. These results justify prospective studies to evaluate switching or intensifying therapy based on early on-treatment ctDNA changes.

In the context of the growing impact of conceptual density functional theory (DFT) as one of the most successful chemical reactivity theories, response functions up to second order have now been widely applied; in recent years, among others, particular attention has been focused on the linear response function and also extensions to higher order have been put forward. As the larger part of these studies have been carried using a finite difference approach to compute these concepts, we now embarked on (an extension of) an analytical approach to conceptual DFT. With the ultimate aim of providing a complete set of analytically computable second order properties, including the softness and hardness kernels, the hardness as the simplest second order response function is scrutinized again with numerical results highlighting the difference in nature between the analytical hardness (referred to as hardness condition) and the Parr-Pearson absolute chemical hardness. The hardness condition is investigated for its capability to gauge the (de)localization error of density functional approximations (DFAs). The analytical Fukui function, besides overcoming the difficulties in the finite difference approach in treating negatively charged systems, also showcases the errors of deviating from the straight-line behavior using fractional occupation number calculations. Subsequently, the softness kernel and its atom-condensed inverse, the hardness matrix, are accessed through the Berkowitz-Parr relation. Revisiting the softness kernel confirms and extends previous discussions on how Kohn’s Nearsightedness of Electronic Matter principle can be retrieved and identified as the physicist’s version of the chemist’s “transferability of functional groups” concept. The accurate, analytical hardness matrix evaluation on the other hand provides further support for the basics of Nalewajski’s charge sensitivity analysis. Based on Parr and Liu’s functional expansion of the energy functional, a new energy decomposition is introduced with an order of magnitude analysis of the different terms for a series of simple molecules both at their equilibrium geometry and upon variation in bond length and dihedral angle. Finally, for the first time, the perturbation expansion of the energy functional is studied numerically up to second order now that all response functions and integration techniques are at hand. The perturbation expansion energies are in excellent agreement with those obtained directly from DFA calculations giving confidence in the convergence of the perturbation series and its use in judging the importance of the different terms in reactivity investigations.

Akkermansia muciniphilais a gut bacterium that colonizes the gut mucosa, has a role in maintaining gut health and shows promise for potential therapeutic applications. The discovery of A. muciniphilaas an important member of our gut microbiome, occupying an extraordinary niche in the human gut, has led to new hypotheses on gut health, beneficial microorganisms and host–microbiota interactions. This microorganism has established a unique position in human microbiome research, similar to its role in the gut ecosystem. Its unique traits in using mucin sugars and mechanisms of action that can modify host health have made A. muciniphilaa subject of enormous attention from multiple research fields. A. muciniphilais becoming a model organism studied for its ability to modulate human health and gut microbiome structure, leading to commercial products, a genetic model and possible probiotic formulations. This Review provides an overview of A. muciniphilaand Akkermansiagenus phylogeny, ecophysiology and diversity. Furthermore, the Review discusses perspectives on ecology, strategies for harnessing beneficial effects of A. muciniphilafor human mucosal metabolic and gut health, and its potential as a biomarker for diagnostics and prognostics.

The linear response kernel also referred to as linear response function (LRF) in the framework of conceptual density functional theory has gained tremendous success in time-dependent density functional theory. Comparatively less attention has been devoted to the LRF from a chemical reactivity perspective in its time- or frequency-independent context, although it has recently been used to qualitatively describe electron delocalization, (anti-)aromaticity, inductive and mesomeric effects, etc. Despite these successes, which were obtained by approximating the LRF using the independent particle approximation deriving from a coupled-perturbed Kohn–Sham computation, the robustness of this LRF approach needs to be assessed. In this work, we compute the LRF at four levels of approximation (independent particle approximation, random phase approximation, Hartree–Fock approximation, and the (exact) DFT (density functional theory) expression) using functionals from the first four rungs of Jacob’s ladder of exchange-correlation energy functionals. To scrutinize the impact of these approximations, new visualization strategies are discussed and systematized. The overall conclusion is that the independent particle approximation yields qualitatively correct results (ergo previous conceptual applications of the LRF are trustworthy), but for quantitative results, LRF expressions including coulomb and exchange(-correlation) terms should be included. With respect to functionals, density-gradient contributions to the exchange-correlation kernel are less than 10% and may be omitted safely where that is preferable computationally.

Top-down stress regulation, important for military operational performance and mental health, involves emotional working memory and the dorsolateral prefrontal cortex (DLPFC). Multisession transcranial direct current stimulation (tDCS) applied over the DLPFC during working memory training has been shown to improve working memory performance. This study tested the hypothesis that combined tDCS with working memory training also improves top-down stress regulation. However, tDCS response differs between individuals. Resting-state electrophysiological brain activity was post hoc explored as a possible predictor of tDCS response. The predictive value of the ratio between slow-wave theta oscillations and fast-wave beta oscillations (theta/beta ratio) was examined, together with the previously identified tDCS response predictors age, education, and baseline working memory performance.

Background: Diagnosis of cerebrovascular disease is based on both clinical and radiological findings, however, they do not always correlate.Aims: To investigate ischemic stroke recurrence and mortality in patients with different imaging phenotypes of ischemic cerebrovascular disease.Methods: Within the SMART-MR study, a prospective patient cohort with arterial disease, cerebrovascular diseases of participants at baseline were classified as no cerebrovascular disease (reference group, n= 828), symptomatic cerebrovascular disease (n= 204), covert vascular lesions (n= 156), or imaging negative ischemia (n= 90) based upon clinical and MRI findings. Ischemic strokes and deaths were collected at 6 month-intervals up to 17 years of follow-up. With Cox regression, relationships between phenotype and ischemic stroke recurrence, cardiovascular mortality, and non-vascular mortality were studied adjusted for age, sex, and cardiovascular risk factors.Results: Compared to reference group risk for recurrent ischemic stroke was increased not only in the symptomatic cerebrovascular disease (HR 3.9, 95% CI 2.3–6.6), but also in the covert vascular lesion (HR 2.5, 95% CI 1.3–4.8) and the imaging negative ischemia groups (HR 2.4, 95% CI 1.1–5.5). Risk for cardiovascular mortality was increased in the symptomatic cerebrovascular disease (HR 2.2, 95% CI 1.5–3.2) and covert vascular lesions groups (HR 2.3, 95% CI 1.5–3.4), while the risk was less strong but also increased in the imaging negative ischemia group (HR 1.7, 95% CI 0.9–3.0).Conclusions: People with all imaging phenotypes of cerebrovascular disease have increased risk of recurrent ischemic stroke and mortality compared to other arterial diseases. Strict preventive measures should be performed even when imaging findings or clinical symptoms are absent.Data access statement: For use of anonymized data, a reasonable request has to be made in writing to the UCC-SMART study group and the third party has to sign a confidentiality agreement.

People with HIV generally have more ageing-associated comorbidities than those without HIV. We aimed to establish whether the difference in comorbidities and their disease burden changes with ageing.

Anti-Felkin–Anh diastereoselectivity can be achieved for nucleophilic additions to α-chiral ketones upon stretching the ketone with a mechanical pulling force. Herein, a mechanochemical Felkin–Anh model is proposed for predicting the outcome of a nucleophilic addition to an α-chiral ketone. Essentially, the fully stretched chiral ketone has one substituent shielding each side of the carbonyl, in contrast to the Felkin–Anh model, in which free rotation around a bond is required to achieve the two rotamers of the ketone. Depending on the pulling scenario, either Felkin–Anh or anti-Felkin–Anh diastereoselectivity is obtained. The model is entirely based on the distance between the pulling points, which is maximized in the anti-periplanar arrangement. The major diastereomer is associated with the approach with the least steric interactions. The intuitive model is validated by means of mechanochemical density functional theory calculations. Importantly, the ketone is fully stretched in the sub 1 nN force regime, thus minimizing the risk of undesired homolytic bond rupture. Moreover, the mechanical force is not used for lowering the reaction barriers associated with the nucleophilic addition; instead, it is solely applied for locking the conformation of a molecule and provoking otherwise inaccessible reaction pathways on the force-modified potential energy surface.

Circulating tumor DNA (ctDNA) is a promising new biomarker with multiple potential applications in cancer care. Estimating total cost of ctDNA testing is necessary for reimbursement and implementation, but challenging because of variations in workflow. We aimed to develop a micro-costing framework for consistent cost calculation of ctDNA testing. First, the foundation of the framework was built, based on the complete step-wise diagnostic workflow of ctDNA testing. Second, the costing method was set up, including costs for personnel, materials, equipment, overhead, and failures. Third, the framework was evaluated by experts and applied to six case studies, including PCR-, mass spectrometry–, and next-generation sequencing–based platforms, from three Dutch hospitals. The developed ctDNA micro-costing framework includes the diagnostic workflow from blood sample collection to diagnostic test result. The framework was developed from a Dutch perspective and takes testing volume into account. An open access tool is provided to allow for laboratory-specific calculations to explore the total costs of ctDNA testing specific workflow parameters matching the setting of interest. It also allows to straightforwardly assess the impact of alternative prices or assumptions on the cost per sample by simply varying the input parameters. The case studies showed a wide range of costs, from €168 to €7638 ($199 to $9124) per sample, and generated information. These costs are sensitive to the (coverage of) platform, setting, and testing volume.

•To have an interest in the interrelationships between the actors of the cluster from the perspective of governance and institutional arrangements, helps to overcome the comment that differences are a result in path dependency.•Of course, as said, there is path dependency.•Events in the past do have their influence on later developments.•But these events are rooted themselves in certain conditions.•The path of the cluster is characterized by events and crossings.•In this paper these are the general dynamics.•These dynamics have an effect.•But the feedback on these crossings is influenced by the factors as operationalized by the sensitizing concepts researched in this paper.•They can be linked to the existence of different political economic structures that make up the institutional arrangements that together make up for the existence of shared values.•These differences, often stemming from the past, could be partly explanatory for differences in the appearance of these sensitizing concepts.

Pregnancy-related venous thromboembolism is a leading cause of maternal morbidity and mortality, and thromboprophylaxis is indicated in pregnant and post-partum women with a history of venous thromboembolism. The optimal dose of low-molecular-weight heparin to prevent recurrent venous thromboembolism in pregnancy and the post-partum period is uncertain.

Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P< 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2Aand FURIN) and variants (such as at GRK5and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries.

STN-DBS is a cornerstone in the treatment of advanced Parkinson’s disease (PD). The traditional approach is to use an awake operative technique with microelectrode recording (MER). However, more centers start using an asleep MRI-guided technique without MER. We systematically reviewed the literature to compare STN-DBS surgery with and without MER for differences in clinical outcome. We systematically searched PubMed, Embase, MEDLINE, and Web of Science databases for randomized clinical trials and consecutive cohort studies published between 01-01-2000 and 26-08-2021, that included at least 10 PD patients who had received bilateral STN-DBS. 2,129 articles were identified. After abstract screening and full-text review, 26 studies were included in the final analysis, comprising a total of 34 study groups (29 MER and 5 non-MER). The standardized mean difference (SMD) in change in motor symptoms between baseline (OFF medication) and 6–24 months follow-up (OFF medication and ON stimulation) was 1.64 for the MER group and 1.87 for non-MER group (p = 0.59). SMD in change in levodopa equivalent daily dose (LEDD) was 1.14 for the MER group and 0.65 for non-MER group (p < 0.01). Insufficient data were available for comparative analysis of PDQ-39 and complications. The change in motor symptoms from baseline to follow-up did not differ between studies that used MER and those that did not. The postoperative reduction in LEDD from baseline to follow-up was greater in the MER-group. In the absence of high-quality studies comparing both methods, there is a clear need for a well-designed comparative trial.

Microbe–microbe interactions in the human gut are influenced by host-derived glycans and diet. The high complexity of the gut microbiome poses a major challenge for unraveling the metabolic interactions and trophic roles of key microbes. Synthetic minimal microbiomes provide a pragmatic approach to investigate their ecology including metabolic interactions. Here, we rationally designed a synthetic microbiome termed Mucin and Diet based Minimal Microbiome (MDb-MM) by taking into account known physiological features of 16 key bacteria. We combined 16S rRNA gene-based composition analysis, metabolite measurements and metatranscriptomics to investigate community dynamics, stability, inter-species metabolic interactions and their trophic roles. The 16 species co-existed in the in vitro gut ecosystems containing a mixture of complex substrates representing dietary fibers and mucin. The triplicate MDb-MM’s followed the Taylor’s power law and exhibited strikingly similar ecological and metabolic patterns. The MDb-MM exhibited resistance and resilience to temporal perturbations as evidenced by the abundance and metabolic end products. Microbe-specific temporal dynamics in transcriptional niche overlap and trophic interaction network explained the observed co-existence in a competitive minimal microbiome. Overall, the present study provides crucial insights into the co-existence, metabolic niches and trophic roles of key intestinal microbes in a highly dynamic and competitive in vitro ecosystem.

The proportion of open pelvic fractures in the paediatric population is relatively high. While operative fixation is the primary approach for managing open pelvic fractures in adults, there is limited literature on treatment outcomes in Children, particularly regarding long-term musculoskeletal, neurological, and urogenital function.

Bilateral deep brain stimulation of the subthalamic nucleus (STN-DBS) has become a cornerstone in the advanced treatment of Parkinson’s disease (PD). Despite its well-established clinical benefit, there is a significant variation in the way surgery is performed. Most centers operate with the patient awake to allow for microelectrode recording (MER) and intraoperative clinical testing. However, technical advances in MR imaging and MRI-guided surgery raise the question whether MER and intraoperative clinical testing still have added value in DBS-surgery. To evaluate the added value of MER and intraoperative clinical testing to determine final lead position in awake MRI-guided and stereotactic CT-verified STN-DBS surgery for PD. 29 consecutive patients were analyzed retrospectively. Patients underwent awake bilateral STN-DBS with MER and intraoperative clinical testing. The role of MER and clinical testing in determining final lead position was evaluated. Furthermore, interobserver variability in determining the MRI-defined STN along the planned trajectory was investigated. Clinical improvement was evaluated at 12 months follow-up and adverse events were recorded. 98% of final leads were placed in the central MER-track with an accuracy of 0.88±0.45 mm. Interobserver variability of the MRI-defined STN was 0.84±0.09. Compared to baseline, mean improvement in MDS-UPDRS-III, PDQ-39 and LEDD were 26.7±16.0 points (54%) (p < 0.001), 9.0±20.0 points (19%) (p = 0.025), and 794±434 mg/day (59%) (p < 0.001) respectively. There were 19 adverse events in 11 patients, one of which (lead malposition requiring immediate postoperative revision) was a serious adverse event. MER and intraoperative clinical testing had no additional value in determining final lead position. These results changed our daily clinical practice to an asleep MRI-guided and stereotactic CT-verified approach.

Microbe–microbe interactions in the human gut are influenced by host-derived glycans and diet. The high complexity of the gut microbiome poses a major challenge for unraveling the metabolic interactions and trophic roles of key microbes. Synthetic minimal microbiomes provide a pragmatic approach to investigate their ecology including metabolic interactions. Here, we rationally designed a synthetic microbiome termed Mucin and Diet based Minimal Microbiome (MDb-MM) by taking into account known physiological features of 16 key bacteria. We combined 16S rRNA gene-based composition analysis, metabolite measurements and metatranscriptomics to investigate community dynamics, stability, inter-species metabolic interactions and their trophic roles. The 16 species co-existed in the in vitro gut ecosystems containing a mixture of complex substrates representing dietary fibers and mucin. The triplicate MDb-MM’s followed the Taylor’s power law and exhibited strikingly similar ecological and metabolic patterns. The MDb-MM exhibited resistance and resilience to temporal perturbations as evidenced by the abundance and metabolic end products. Microbe-specific temporal dynamics in transcriptional niche overlap and trophic interaction network explained the observed co-existence in a competitive minimal microbiome. Overall, the present study provides crucial insights into the co-existence, metabolic niches and trophic roles of key intestinal microbes in a highly dynamic and competitive in vitro ecosystem.

Reporting and learning from preventable adverse events is crucial to improve patient safety. Although physicians should file and analyse adverse events by law in The Netherlands, it is unknown if these reporting systems are sufficiently used in clinical practice. This study is a substudy of the multicenter RICAT trial, a successful quality improvement project to reduce inappropriate use of intravenous and urinary catheters in medical wards in seven hospitals, in which we screened 5696 patients and documented 803 catheter-related complications. We also checked the adverse events reporting systems of these patients and found that only 13 (1.6%) of 803 catheter-related complications were registered. Of the infectious complications only five (10.9%) of 46 catheter-associated bloodstream infections and urinary tract infections were registered. We conclude that the reported complications were a major underestimation of the real complication practice in medical wards in The Netherlands.The RICAT trial is registered at Netherlands Trial Register, trial NL5438.

ObjectivesGeneral practitioners (GPs) and sexual health centres (SHCs) are the main providers of HIV testing and diagnose two-thirds of HIV infections in the Netherlands. We compared regional HIV testing and positivity by GPs versus SHCs to gain insight into strategies to improve HIV testing, to enable timely detection of HIV infections.MethodsLaboratory data (2011–2018) on HIV testing by GPs and SHCs in five Dutch regions with varying levels of urbanisation were evaluated. Regional HIV testing rates per 10 000 residents ≥15 years (mean over period and annual) were compared between providers using negative binomial generalised additive models and additionally stratified by sex and age (15–29 years, 30–44 years, 45–59 years, ≥60 years). χ2tests were used to compare positivity percentage between the two groups of providers.ResultsIn the study period, 505 167 HIV tests (GP 36%, SHC 64%) were performed. The highest HIV testing rates were observed in highly urbanised regions, with large regional variations. The HIV testing rates ranged from 28 to 178 per 10 000 residents by GPs and from 30 to 378 per 10 000 by SHCs. Testing rates by GPs were lower than by SHCs in three regions and comparable in two. In all regions, men were tested less by GPs than by SHCs; for women, this varied by region. Among those aged 15–29 years old, GPs’ testing rates were lower than SHCs’, while this was reversed in older age categories in four out of five regions. The overall mean HIV positivity was 0.4%. In contrast to other regions, positivity in Amsterdam was significantly higher among individuals tested by GPs than by SHCs.ConclusionsThis retrospective observational study shows that besides SHCs, who perform opt-out testing for key groups, GPs play a prominent role in HIV testing, especially in non-key populations, such as women and older individuals. Large regional variation exists, requiring region-specific interventions to improve GPs’ HIV testing practices.

Patients with an inferior vena cava (IVC) filter that remains in situ encounter a lifelong increased risk of deep vein thrombosis and IVC filter complications including fracture, perforation, and IVC filter thrombotic occlusion. Data on the safety of becoming pregnant with an in situ IVC filter are scarce. The objective was to evaluate the risk of complications of in situ IVC filters during pregnancy. We performed a retrospective cohort study of pregnant patients with an in situ IVC filter from a tertiary center between 2000 and 2020. We collected data on complications of IVC filters and pregnancy outcomes. Additionally, we performed a systematic literature search in MEDLINE, Embase, and gray literature. We identified 7 pregnancies in 4 patients with in situ IVC filters with a mean time since IVC filter insertion of 3 years (range, 1-8). No complications of IVC filter occurred during pregnancy. Review of literature yielded five studies including 13 pregnancies in 9 patients. In 1 pregnancy a pre-existent, until then asymptomatic, chronic perforation of the vena cava wall by the IVC filter caused major bleeding and uterine trauma with fetal loss. Overall, the complication rate was 5%. It seems safe to become pregnant with an indwelling IVC filter that is intact and does not show signs of perforation, but because of the low number of cases, no firm conclusions about safety of in situ IVC filters during pregnancy can be drawn. We suggest imaging before pregnancy to reveal asymptomatic IVC filter complications.

Patients with an inferior vena cava (IVC) filter that remains in situ encounter a lifelong increased risk of deep vein thrombosis and IVC filter complications including fracture, perforation, and IVC filter thrombotic occlusion. Data on the safety of becoming pregnant with an in situ IVC filter are scarce. The objective was to evaluate the risk of complications of in situ IVC filters during pregnancy. We performed a retrospective cohort study of pregnant patients with an in situ IVC filter from a tertiary center between 2000 and 2020. We collected data on complications of IVC filters and pregnancy outcomes. Additionally, we performed a systematic literature search in MEDLINE, Embase, and gray literature. We identified 7 pregnancies in 4 patients with in situ IVC filters with a mean time since IVC filter insertion of 3 years (range, 1-8). No complications of IVC filter occurred during pregnancy. Review of literature yielded five studies including 13 pregnancies in 9 patients. In 1 pregnancy a pre-existent, until then asymptomatic, chronic perforation of the vena cava wall by the IVC filter caused major bleeding and uterine trauma with fetal loss. Overall, the complication rate was 5%. It seems safe to become pregnant with an indwelling IVC filter that is intact and does not show signs of perforation, but because of the low number of cases, no firm conclusions about safety of in situ IVC filters during pregnancy can be drawn. We suggest imaging before pregnancy to reveal asymptomatic IVC filter complications.