Aspirin for preeclampsia prevention in low- and middle-income countries: mind the gaps

Preeclampsia is a syndrome that continues to be a major contributor to maternal and neonatal mortality, especially in low-income countries. Low-dose aspirin reduces the risk of preeclampsia, but the mechanism is still unknown. Risk factors to identify women at risk of preeclampsia are based on clinical characteristics. Women identified as high-risk would benefit from aspirin treatment initiated, preferably at the end of the first trimester. Current efforts have largely focused on developing screening algorithms that incorporate clinical risk factors, maternal biomarkers, and uterine artery Doppler evaluated in the first trimester. However, most studies on preeclampsia are conducted in high-income settings, raising uncertainties about whether the information gained can be totally applied in low-resource settings. In low- and middle-income countries, lack of adequate antenatal care and late commencement of antenatal care visits pose significant challenges for both screening for preeclampsia and initiating aspirin treatment. Furthermore, the preventive effect of first-trimester screening based on algorithms and subsequent aspirin treatment is primarily seen for preterm preeclampsia, and reviews indicate minimal or no impact on reducing the risk of term preeclampsia. The lack of evidence regarding the effectiveness of aspirin in preventing term preeclampsia is a crucial concern, as 75% of women will develop this subtype of the syndrome. Regarding adverse outcomes, low-dose aspirin has been linked to a possible higher risk of postpartum hemorrhage, a condition as deadly as preeclampsia in many low- and middle-income countries. The increased risk of postpartum hemorrhage among women in low-income settings should be taken into consideration when discussing which pregnant women would benefit from the use of aspirin and the ideal aspirin dosage for preventing preeclampsia. In addition, women's adherence to aspirin during pregnancy is crucial for determining its effectiveness and complications, an aspect often overlooked in trials. In this review, we analyze the knowledge gaps that must be addressed to safely increase low-dose aspirin use in low- and middle-income countries, and we propose directions for future research.

Preeclampsia epidemiology(ies) and pathophysiology(ies)

Preeclampsia/eclampsia was first described 2000 years ago. Concepts guiding diagnosis have changed over time making longitudinal studies challenging. Similarly, concepts of pathophysiology have evolved from eclampsia as a pregnancy seizure disorder to preeclampsia as a hypertensive and renal disorder to our current concept of a preeclampsia as a pregnancy specific, multisystemic inflammatory disorder. Although preeclampsia is pregnancy specific and many pathophysiologic findings begin to resolve with delivery, its impact extends beyond pregnancy. The risk of cardiovascular and neurological disease is increased after pregnancy in women who have had preeclampsia. The disorder is not a disease, but a syndrome and emerging data indicate multiple pathways to the syndrome. It is likely that our failure to have a major impact on prediction and prevention despite a large increase in understanding is due to the existence of multiple subtypes of preeclampsia. This concept should guide future research.

Prepregnancy obesity and risk of placental inflammation at term: a selection bias analysis

PURPOSE

Placental histopathology is a resource for investigating obesity-associated pregnancy conditions. However, studies oversample adverse pregnancies, biasing findings. We examine the association between prepregnancy obesity (risk factor for inflammation) and histologic placental inflammation (correlated with impaired infant neurodevelopment) and how selection bias may influence the association.

METHODS

Singleton term deliveries between 2008 and 2012 from the Magee Obstetric Maternal and Infant database were analyzed. Prepregnancy body mass index (BMI) was categorized as underweight, lean (referent), overweight, and obese. Outcomes were diagnoses of acute (acute chorioamnionitis and fetal inflammation) and chronic placental inflammation (chronic villitis). Risk ratios for associations between BMI and placental inflammation were estimated using selection bias approaches: complete case, exclusion of pregnancy complications, multiple imputation, and inverse probability weighting. E-values approximated how susceptible estimates were to residual selection bias.

RESULTS

Across methods, obesity was associated with an 8-15% lower risk of acute chorioamnionitis, a 7%-14% lower risk of acute fetal inflammation, and a 12%-30% higher risk of chronic villitis relative to lean women. E-values indicated modest residual selection bias could explain away associations, though few measured indications of placental evaluations met this threshold.

CONCLUSIONS

Obesity may contribute to placental inflammation, and we highlight robust methods to analyze clinical data susceptible to selection bias.

Recruiting and retaining nulliparous individuals with a family history of hypertensive disorders of pregnancy to participate in scientific research prior to pregnancy: The Sisterhood Study

Introduction

Recruiting women with a family history (FH) of hypertensive disorders of pregnancy (HDP) to participate in research before pregnancy could offer insight into genetic and lifestyle factors that incur higher risk of cardiovascular disease during pregnancy and throughout the life course.

Methods

The Sisterhood Study piloted low-touch, remote recruitment strategies that relied on women with a history of preeclampsia to share study information with family and friends. It aimed to enroll 150 women with a FH of HDP and 150 controls.

Results

The study recruited 328 women (104 with a FH of HDP, 131 without a FH, and 93 with unknown FH) prior to pregnancy. The majority identified as non-Hispanic White (74.7%) and had > high school education (91.8%).

Discussion

Although the population was enriched with nulliparous women with a FH of HDP, it was not sufficient to recruit a diverse cohort large enough to meet the study aim.

PREPARE: A Stepped-Wedge Cluster-Randomized Trial to Evaluate Whether Risk Stratification Can Reduce Preterm Deliveries Among Patients With Suspected or Confirmed Preterm Preeclampsia

BACKGROUND

Early delivery in preterm preeclampsia may reduce the risks for the patient, but consequences of prematurity may be substantial for the baby. This trial evaluated whether the implementation of a risk stratification model could safely reduce prematurity.

METHODS

This was a stepped-wedge cluster-randomized trial in seven clusters. Patients presenting with suspected or confirmed preeclampsia between 20+0 and 36+6 gestational weeks were considered eligible. At the start of the trial, all centers were allocated in the preintervention phase, and patients enrolled in this phase were managed according to local treatment guidance. Subsequently, every 4 months, 1 randomly allocated cluster transitioned to the intervention. Patients enrolled in the intervention phase had sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio and preeclampsia integrated estimate of risk assessments performed. If sFlt-1/PlGF ≤38 and preeclampsia integrated estimate of risk <10%, patients were considered low risk and clinicians received recommendations to defer delivery. If sFlt-1/PlGF >38 and preeclampsia integrated estimate of risk ≥10%, patients were considered not low risk, and clinicians received recommendations to increase surveillance. The primary outcome was the proportion of patients with preterm preeclampsia delivered prematurely out of total deliveries.

RESULTS

Between March 25, 2017 and December 24, 2019, 586 and 563 patients were analyzed in the intervention and usual care groups, respectively. The event rate was 1.09% in the intervention group, and 1.37% in the usual care group. After prespecified adjustments for variation between and within clusters over time, the adjusted risk ratio was 1.45 ([95% CI, 1.04-2.02]; P=0.029), indicating a higher risk of preterm deliveries in the intervention group. Post hoc analysis including calculation of risk differences did not show evidence of statistical differences. Abnormal sFlt-1/PlGF was associated with a higher rate of identifying preeclampsia with severe features.

CONCLUSIONS

The introduction of an intervention based on biomarkers and clinical factors for risk stratification did not lead to reductions in preterm deliveries. Further training on the interpretation of disease severity in preeclampsia and the development of additional risk stratification is needed before adoption into clinical practice.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03073317.

Care plan for individuals at risk for preeclampsia: shared approach to education, strategies for prevention, surveillance, and follow-up

Preeclampsia is a multisystemic disorder of pregnancy that affects 250,000 pregnant individuals in the United States and approximately 10 million worldwide per annum. Preeclampsia is associated with substantial immediate morbidity and mortality but also long-term morbidity for both mother and offspring. It is now clearly established that a low dose of aspirin given daily, beginning early in pregnancy modestly reduces the occurrence of preeclampsia. Low-dose aspirin seems safe, but because there is a paucity of information about long-term effects on the infant, it is not recommended for all pregnant individuals. Thus, several expert groups have identified clinical factors that indicate sufficient risk to recommend low-dose aspirin preventive therapy. These risk factors may be complemented by biochemical and/or biophysical tests that either indicate increased probability of preeclampsia in individuals with clinical risk factors, or more importantly, identify increased likelihood in those without other evident risk. In addition, the opportunity exists to provide this population with additional care that may prevent or mitigate the short- and long-term effects of preeclampsia. Patient and provider education, increased surveillance, behavioral modification, and other approaches to improve outcomes in these individuals can improve the chance of a healthy outcome. We assembled a group with diverse, relevant expertise (clinicians, investigators, advocates, and public and private stakeholders) to develop a care plan in which providers and pregnant individuals at risk can work together to reduce the risk of preeclampsia and associated morbidities. The plan is for care of individuals at moderate to high risk for developing preeclampsia, sufficient to receive low-dose aspirin therapy, as identified by clinical and/or laboratory findings. The recommendations are presented using the GRADE methodology with the quality of evidence upon which each is based. In addition, printable appendices with concise summaries of the care plan's recommendations for patients and healthcare providers are provided. We believe that this shared approach to care will facilitate prevention of preeclampsia and its attendant short- and long-term morbidity in patients identified as at risk for development of this disorder.

Inflammatory markers are elevated in early pregnancy, but not late pregnancy, in women with overweight and obesity that later develop preeclampsia

PROBLEM

Obesity and preeclampsia both involve a pathological inflammatory response, which may be how obesity increases preeclampsia risk. Previous studies have failed to assess robust measurements of inflammatory markers across gestation, specifically in overweight/ obese women in the context of preeclampsia.

METHOD OF STUDY

We measured 20 inflammatory markers in plasma via multiplex assay (ThermoFisher Inflammation 20 plex Human ProcartaPlex Panel) across the three trimesters of pregnancy in an existing cohort of overweight and obese women who developed preeclampsia (n = 37) and without preeclampsia (n = 74). Mann-Whitney U tests examined differences in inflammatory marker concentrations between cases and controls. Repeated measures ANOVA tests were used to explore differences in inflammatory marker concentrations over time within cases and controls.

RESULTS

Pro-inflammatory markers (IL-1α, IL-1β, IL-6, IFN-α, IFN-γ, GM-CSF, IL-12p70, IL-17α, TNF-α, IL-8) and anti-inflammatory markers (IL-4, IL-10, IL-13) were higher in the first and second trimester in participants who later developed preeclampsia compared to those who did not (p < .05). Only TNF-α and IL-8 remained elevated in the third trimester. Inflammatory markers did not change across pregnancy in preeclampsia cases but did increase across pregnancy in controls.

CONCLUSION

Our findings diverge from prior studies, predominantly of non-obese women, that report lower circulating concentrations of anti-inflammatory cytokines in preeclampsia versus normotensive pregnancy, particularly by late pregnancy. We posit that women with overweight and obesity who develop preeclampsia entered pregnancy with a heightened pro-inflammatory state likely related to obesity, which increased risk for preeclampsia. Further studies are needed to investigate if inflammatory maker profiles differ between obese and non-obese women.

Is the Association Between Fruits and Vegetables and Preeclampsia Due to Higher Dietary Vitamin C and Carotenoid Intakes?

BACKGROUND

Diets dense in fruits and vegetables are associated with a reduced risk of preeclampsia, but pathways underlying this relationship are unclear. Dietary antioxidants may contribute to the protective effect.

OBJECTIVE

We determined the extent to which the effect of dietary fruit and vegetable density on preeclampsia is because of high intakes of dietary vitamin C and carotenoids.

METHODS

We used data from 7572 participants in the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be (8 United States medical centers, 2010‒2013). Usual daily periconceptional intake of total fruits and total vegetables was estimated from a food frequency questionnaire. We estimated the indirect effect of ≥2.5 cups/1000 kcal of fruits and vegetables through vitamin C and carotenoid on the risk of preeclampsia. We estimated these effects using targeted maximum likelihood estimation and an ensemble of machine learning algorithms, adjusting for confounders, including other dietary components, health behaviors, and psychological, neighborhood, and sociodemographic factors.

RESULTS

Participants who consumed ≥2.5 cups of fruits and vegetables per 1000 kcal were less likely than those who consumed <2.5 cups/1000 kcal to develop preeclampsia (6.4% compared with 8.6%). After confounder adjustment, we observed that higher fruit and vegetable density was associated with 2 fewer cases of preeclampsia (risk difference: -2.0; 95% CI: -3.9, -0.1)/100 pregnancies compared with lower density diets. High dietary vitamin C and carotenoid intake was not associated with preeclampsia. The protective effect of high fruit and vegetable density on the risk of preeclampsia and late-onset preeclampsia was not mediated through dietary vitamin C and carotenoids.

CONCLUSIONS

Evaluating other nutrients and bioactives in fruits and vegetables and their synergy is worthwhile, along with characterizing the effect of individual fruits or vegetables on preeclampsia risk.

Early Pregnancy Systolic Blood Pressure Patterns Predict Early- and Later-Onset Preeclampsia and Gestational Hypertension Among Ostensibly Low-to-Moderate Risk Groups

Background Clinical risk factors, a single blood pressure (BP) measurement, current biomarkers, and biophysical parameters can effectively identify risk of early-onset preeclampsia but have limited ability to predict later-onset preeclampsia and gestational hypertension. Clinical BP patterns hold promise to improve early risk stratification for hypertensive disorders of pregnancy. Methods and Results After excluding preexisting hypertension, heart, kidney, or liver disease, or prior preeclampsia, the retrospective cohort (n=249 892) all had systolic BP <140 mm Hg and diastolic BP <90 mm Hg or a single BP elevation ≤20 weeks' gestation, prenatal care at <14 weeks' gestation, and a still or live birth delivery at Kaiser Permanente Northern California hospitals (2009-2019). The sample was randomly split into development (N=174 925; 70%) and validation (n=74 967; 30%) data sets. Predictive performance of multinomial logistic regression models for early-onset (<34 weeks) preeclampsia, later-onset (≥34 weeks) preeclampsia, and gestational hypertension was evaluated in the validation data set. There were 1008 (0.4%), 10 766 (4.3%), and 11 514 (4.6%) patients with early-onset preeclampsia, later-onset preeclampsia, and gestation hypertension, respectively. Models with 6 systolic BP trajectory groups (0-20 weeks' gestation) plus standard clinical risk factors performed substantially better than risk factors alone to predict early- and later-onset preeclampsia and gestational hypertension, with C-statistics (95% CIs) of 0.747 (0.720-0.775), 0.730 (0.722-0.739), and 0.768 (0.761-0.776) versus 0.688 (0.659-0.717), 0.695 (0.686-0.704) and 0.692 (0.683-0.701), respectively, with excellent calibration (Hosmer-Lemeshow P=0.99, 0.99, and 0.74, respectively). Conclusions Early pregnancy BP patterns up to 20 weeks' gestation plus clinical, social, and behavioral factors more accurately discriminate hypertensive disorders of pregnancy risk among low-to-moderate risk pregnancies. Early pregnancy BP trajectories improve risk stratification to reveal higher-risk individuals hidden within ostensibly low-to-moderate risk groups and lower-risk individuals considered at higher risk by US Preventive Services Task Force criteria.

Lipidomics Reveals Elevated Plasmalogens in Women with Obesity Who Develop Preeclampsia

Objective: Preeclampsia (PE) is a prevalent pregnancy disorder worldwide with limited preventative treatments available. Obesity triples the risk for PE, yet only 10% of women with obesity develop PE. The factors that distinguish PE from uncomplicated pregnancies in the context of obesity have not been fully established. Methods: We studied a cohort of women with obesity throughout pregnancy to identify lipid mediators and/or biomarkers of PE. Blood samples were collected at each trimester and analyzed by both targeted lipidomics and standard lipid panels. Individual lipid species were compared by PE status at each trimester, as well as by self-identified race (Black vs. White) and fetal sex. Results: Standard lipid panels and clinical measurements revealed few differences between PE and uncomplicated pregnancies. Targeted lipidomics, however, identified plasmalogen, phosphatidylethanolamine, and free fatty acid species that were elevated in the third trimester of women with PE. Furthermore, race and trimester of pregnancy were considerable sources of plasma lipidomic variation in women with obesity. Conclusions: First and second trimester individual plasma lipid species do not predict the development of PE in obese women. In the third trimester, PE patients have elevated levels of plasmalogens-a class of lipoprotein-associated phospholipids that have been implicated in the response to oxidative stress.

Elevated levels of chloramines and chlorine detected near an indoor sports complex

Chloramines (NH₂Cl, NHCl₂, and NCl₃) are toxic compounds that can be created during the use of bleach-based disinfectants that contain hypochlorous acid (HOCl) and the hypochlorite ion (OCl^-) as their active ingredients. Chloramines can then readily transfer from the aqueous-phase to the gas-phase. Atmospheric chemical ionization mass spectrometry using iodide adduct chemistry (I-CIMS) made observations across two periods (2014 and 2016) at an urban background site on the University of Leicester campus (Leicester, UK). Both monochloramine (NH₂Cl) and molecular chlorine (Cl₂) were detected and positively identified from calibrated mass spectra during both sampling periods and to our knowledge, this is the first detection of NH₂Cl outdoors. Mixing ratios of NH₂Cl reached up to 2.2 and 4.0 parts per billion by volume (ppbv), with median mixing ratios of 30 and 120 parts per trillion by volume (pptv) during the 2014 and 2016 sampling periods, respectively. Levels of Cl₂ were observed to reach up to 220 and 320 pptv. Analysis of the NH₂Cl and Cl₂ data pointed to the same local source, a nearby indoor sports complex with a swimming pool and a cleaning product storage shed. No appreciable levels of NHCl₂ and NCl₃ were observed outdoors, suggesting the indoor pool was not likely to be the primary source of the observed ambient chloramines, as prior measurements made in indoor pool atmospheres indicate that NCl₃ would be expected to dominate. Instead, these observations point to indoor cleaning and/or cleaning product emissions as the probable source of NH₂Cl and Cl₂ where the measured levels provide indirect evidence for substantial amounts transported from indoors to outdoors. Our upper estimate for total NH₂Cl emissions from the University of Leicester indoor sports complexes scaled for similar sports complexes across the UK is 3.4 × 10⁵ ± 1.1 × 10⁵ μg h^-1 and 0.0017 ± 0.00034 Gg yr^-1, respectively. The Cl-equivalent emissions in HCl are only an order of magnitude less to those from hazardous waste incineration and iron and steel sinter production in the UK National Atmospheric Emissions Inventory (NAEI).

A longitudinal epigenome-wide association study of preeclamptic and normotensive pregnancy

Background

While preeclampsia (PE) is a leading cause of pregnancy-related morbidity/mortality, its underlying mechanisms are not fully understood. DNA methylation (DNAm) is a dynamic regulator of gene expression that may offer insight into PE pathophysiology and/or serve as a biomarker (e.g., risk, subtype, a therapeutic response). This study's purpose was to evaluate for differences in blood-based DNAm across all trimesters between individuals eventually diagnosed with PE (cases) and individuals who remained normotensive throughout pregnancy, did not develop proteinuria, and birthed a normally grown infant (controls).

Results

In the discovery phase, longitudinal, genome-wide DNAm data were generated across three trimesters of pregnancy in 56 participants (n=28 cases, n=28 controls) individually matched on self-identified race, pre-pregnancy body mass index, smoking, and gestational age at sample collection. An epigenome-wide association study (EWAS) was conducted, using surrogate variable analysis to account for unwanted sources of variation. No CpGs met the genome-wide significance p value threshold of 9×10-8, but 16 CpGs (trimester 1: 5; trimester 2: 1; trimester 3: 10) met the suggestive significance threshold of 1×10-5. DNAm data were also evaluated for differentially methylated regions (DMRs) by PE status. Three DMRs in each trimester were significant after Bonferonni-adjustment. Since only third-trimester samples were available from an independent replication sample (n=64 cases, n=50 controls), the top suggestive hits from trimester 3 (cg16155413 and cg21882990 associated with TRAF3IP2-AS1/TRAF3IP2 genes, which also made up the top DMR) were carried forward for replication. During replication, DNAm data were also generated for validation purposes from discovery phase third trimester samples. While significant associations between DNAm and PE status were observed at both sites in the validation sample, no associations between DNAm and PE status were observed in the independent replication sample.

Conclusions

The discovery phase findings for cg16155413/cg21882990 (TRAF3IP2-AS1/TRAF3IP2) were validated with a new platform but were not replicated in an independent sample. Given the differences in participant characteristics between the discovery and replication samples, we cannot rule out important signals for these CpGs. Additional research is warranted for cg16155413/cg21882990, as well as top hits in trimesters 1-2 and significant DMRs that were not examined in the replication phase.

Characterization of placental and decidual cell development in early pregnancy loss by single-cell RNA sequencing

Background

Early pregnancy loss (EPL) presents as sporadic or recurrent miscarriage during the first trimester. In addition to chromosomal defects, EPL may result from impairment of the placental-decidual interface at early gestational age due to gene-environmental interactions.

Methods

To better understand the pathogenesis associated with this impairment, cell development in chorionic villi and decidua of different forms of EPL (sporadic or recurrent) was investigated with single-cell RNA sequencing and compared to that of normal first-trimester tissue.

Results

Unique gene expression signatures were obtained for the different forms of EPL and for normal tissue and the composition of placental and decidual cell clusters in each form was established. In particular, the involvement of macrophages in the EPL phenotypes was identified revealing an immunoactive state.

Conclusion

Differential gene expression and unique marker genes among cell clusters from chorionic villi and decidua of miscarried and normal pregnancies, may lead to identification of biomarker for EPL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00904-5.

The Global Pregnancy Collaboration (CoLab) symposium on short- and long-term outcomes in offspring whose mothers had preeclampsia: A scoping review of clinical evidence

Preeclampsia is a maternal syndrome characterized by the new onset of hypertension after 20 weeks of gestation associated with multisystemic complications leading to high maternal and fetal/neonatal morbidity and mortality. However, sequelae of preeclampsia may extend years after pregnancy in both mothers and their children. In addition to the long-term adverse cardiovascular effects of preeclampsia in the mother, observational studies have reported elevated risk of cardiovascular, metabolic, cerebral and cognitive complications in children born from women with preeclampsia. Less clear is whether the association between maternal preeclampsia and offspring sequelae are causal, or to what degree the associations might be driven by fetal factors including impaired growth and the health of its placenta. Our discussion of these complexities in the 2018 Global Pregnancy Collaboration annual meeting prompted us to write this review. We aimed to summarize the evidence of an association between maternal preeclampsia and neurobehavioral developmental disorders in offspring in hopes of generating greater research interest in this important topic.

Hydrogen chloride (HCl) at ground sites during CalNex 2010 and insight into its thermodynamic properties

Gas phase hydrogen chloride (HCl) was measured at Pasadena and San Joaquin Valley (SJV) ground sites in California during May and June 2010 as part of the CalNex study. Observed mixing ratios were on average 0.83 ppbv at Pasadena, ranging from below detection limit (0.055 ppbv) to 5.95 ppbv, and were on average 0.084 ppbv at SJV with a maximum value of 0.776 ppbv. At both sites, HCl levels were highest during midday and shared similar diurnal variations with HNO3. Coupled phase partitioning behavior was found between HCl/Cl- and HNO3/NO3 - using thermodynamic modelling and observations. Regional modeling of Cl- and HCl using CMAQ captures some of the observed relationships but underestimates measurements by a factor of 5 or more. Chloride in the 2.5-10 μm size range in Pasadena was sometimes higher than sea salt abundances, based on co-measured Na+, implying that sources other than sea salt are important. The acid-displacement of HCl/Cl- by HNO3/NO3 - (phase partitioning of semi-volatile acids) observed at the SJV site can only be explained by aqueous phase reaction despite low RH conditions and suggests the temperature dependence of HCl phase partitioning behavior was strongly impacted by the activity coefficient changes under relevant aerosol conditions (e.g., high ionic strength). Despite the influence from activity coefficients, the gas-particle system was found to be well constrained by other stronger buffers and charge balance so that HCl and Cl- concentrations were reproduced well by thermodynamic models.

Latent class analysis of placental histopathology: a novel approach to classifying early and late preterm births

BACKGROUND

Neonatal morbidity attributable to prematurity predominantly occurs among early preterm births (<32 weeks) rather than late preterm births (32 to <37 weeks). Methods to distinguish early and late preterm births are lacking given the heterogeneity in pathophysiology and risk factors, including maternal obesity. Although preterm births are often characterized by clinical presentation (spontaneous or clinically indicated), classifying deliveries by placental features detected on histopathology reports may help identify subgroups of preterm births with similar etiology and risk factors. Latent class analysis is an empirical approach to characterize preterm births on the basis of observed combinations of placental features.

OBJECTIVE

To identify histopathologic markers that can distinguish early (<32 weeks) and late preterm births (32 to <37 weeks) that are also associated with maternal obesity and neonatal outcomes.

STUDY DESIGN

Women with a singleton preterm birth at University of Pittsburgh Medical Center Magee-Womens Hospital (Pittsburgh, PA) from 2008 to 2012 and a placental evaluation (89% of preterm births) were stratified into early (n=900, 61% spontaneous) and late preterm births (n=3362, 57% spontaneous). Prepregnancy body mass index was self-reported at first prenatal visit and 16 abstracted placental features were analyzed. Placental subgroups (ie, latent classes) of early and late preterm births were determined separately by latent class analysis of placental features. The optimal number of latent classes was selected by comparing fit statistics. The probability of latent class membership across prepregnancy body mass indexes was estimated in early preterm births and in late preterm births by an extension of multinomial regression called pseudo-class regression, adjusting for race, smoking, education, and parity. The frequencies of severe neonatal morbidity (composite outcome: respiratory distress, bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, periventricular leukomalacia, patent ductus arteriosus, and retinopathy of prematurity), small-for-gestational-age, and length of neonatal intensive care unit stay were compared across latent classes by chi-square and Kruskal-Wallis tests.

RESULTS

Early preterm births were grouped into 4 latent classes based on placental histopathologic features: acute inflammation (38% of cases), maternal vascular malperfusion with inflammation (29%), maternal vascular malperfusion (25%), and fetal vascular thrombosis with hemorrhage (8%). As body mass index increased from 20 to 50kg/m², the probability of maternal vascular malperfusion and fetal vascular thrombosis with hemorrhage increased, whereas the probability of maternal vascular malperfusion with inflammation decreased. There was minimal change in the probability of acute inflammation with increasing body mass index. Late preterm births also had 4 latent classes: maternal vascular malperfusion (22%), acute inflammation (12%), fetal vascular thrombosis with hemorrhage (9%), and low-risk pathology (58%). Body mass index was not associated with major changes in likelihood of the latent classes in late preterm births. Associations between body mass index and likelihood of the latent classes were not modified by type of delivery (spontaneous or indicated) in early or late preterm births. Maternal malperfusion and fetal vascular thrombosis with hemorrhage were associated with greater neonatal morbidity than the other latent classes in early and late preterm births.

CONCLUSION

Obesity may predispose women to early but not late preterm birth through placental vascular impairment. Latent class analysis of placental histopathologic data provides an evidence-based approach to group preterm births with shared underlying etiology and risk factors.

Early Pregnancy Blood Pressure Patterns Identify Risk of Hypertensive Disorders of Pregnancy Among Racial and Ethnic Groups

BACKGROUND

Hypertensive disorders of pregnancy are a leading cause of severe maternal morbidity and mortality and confer 4-fold higher perinatal mortality in Black women. Early pregnancy blood pressure patterns may differentiate risk of hypertensive disorders of pregnancy.

METHODS

This study identified distinct blood pressure trajectories from 0 to 20 weeks' gestation to evaluate subsequent pregnancy-related hypertension in a retrospective cohort of 174 925 women with no prior hypertension or history of preeclampsia, prenatal care entry ≤14 weeks, and a stillborn or live singleton birth delivered at Kaiser Permanente Northern California hospitals in 2009 to 2019. We used electronic health records to obtain clinical outcomes, covariables, and longitudinal outpatient blood pressure measurements ≤20 weeks' gestation (mean 4.1 measurements). Latent class trajectory modeling identified 6 blood pressure groups: ultra-low-declining(referent), low-declining, moderate-fast-decline, low-increasing, moderate-stable, and elevated-stable. Multivariable logistic regression evaluated trajectory group-associations with the odds of preeclampsia/eclampsia and gestational hypertension' and effect modification by race-ethnicity and prepregnancy body size.

RESULTS

Compared with ultra-low-declining, adjusted odds ratios (95% confidence intervals [CIs]) for low-increasing, moderate-stable, and elevated-stable groups were 3.25 (2.7-3.9), 5.3 (4.5-6.3), and 9.2 (7.7-11.1) for preeclampsia/eclampsia' and 6.4 (4.9-8.3), 13.6 (10.5-17.7), and 30.2 (23.2-39.4) for gestational hypertension. Race/ethnicity, and prepregnancy obesity modified the trajectory-group associations with preeclampsia/eclampsia (interaction P<0.01), with highest risks for Black, then Hispanic and Asian women for all blood pressure trajectories, and with increasing obesity class.

CONCLUSIONS

Early pregnancy blood pressure patterns revealed racial and ethnic differences in associations with preeclampsia/eclampsia risk within equivalent levels and patterns. These blood pressure patterns may improve individual risk stratification permitting targeted surveillance and early mitigation strategies.

Syncytiotrophoblast stress in preeclampsia: the convergence point for multiple pathways

Preeclampsia evolves in 2 stages: a placental problem that generates signals to the mother to cause a range of responses that comprise the second stage (preeclampsia syndrome). The first stage of early-onset preeclampsia is poor placentation, which we here call malplacentation. The spiral arteries are incompletely remodeled, leading to later placental malperfusion, relatively early in the second half of pregnancy. The long duration of the first stage (several months) is unsurprisingly associated with fetal growth restriction. The first stage of late-onset preeclampsia, approximately 80% of total cases, is shorter (several weeks) and part of a process that is common to all pregnancies. Placental function declines as it outgrows uterine capacity, with increasing chorionic villous packing, compression of the intervillous space, and fetal hypoxia, and causes late-onset clinical presentations such as "unexplained" stillbirths, late-onset fetal growth restriction, or preeclampsia. The second stages of early- and late-onset preeclampsia share syncytiotrophoblast stress as the most relevant feature that causes the maternal syndrome. Syncytiotrophoblast stress signals in the maternal circulation are probably the most specific biomarkers for preeclampsia. In addition, soluble fms-like tyrosine kinase-1 (mainly produced by syncytiotrophoblast) is the best-known biomarker and is routinely used in clinical practice in many locations. How the stress signals change over time in normal pregnancies indicates that syncytiotrophoblast stress begins on average at 30 to 32 weeks' gestation and progresses to term. At term, syncytiotrophoblast shows increasing markers of stress, including apoptosis, pyroptosis, autophagy, syncytial knots, and necrosis. We label this phenotype the "twilight placenta" and argue that it accounts for the clinical problems of postmature pregnancies. Senescence as a stress response differs in multinuclear syncytiotrophoblast from that of mononuclear cells. Syncytiotrophoblast irreversibly acquires part of the senescence phenotype (cell cycle arrest) when it is formed by cell fusion. The 2 pathways converge on the common pathologic endpoint, syncytiotrophoblast stress, and contribute to preeclampsia subtypes. We highlight that the well-known heterogeneity of the preeclampsia syndrome arises from different pathways to this common endpoint, influenced by maternal genetics, epigenetics, lifestyle, and environmental factors with different fetal and maternal responses to the ensuing insults. This complexity mandates a reassessment of our approach to predicting and preventing preeclampsia, and we summarize research priorities to maximize what we can learn about these important issues.

RNA profiles reveal signatures of future health and disease in pregnancy

Maternal morbidity and mortality continue to rise, and pre-eclampsia is a major driver of this burden1. Yet the ability to assess underlying pathophysiology before clinical presentation to enable identification of pregnancies at risk remains elusive. Here we demonstrate the ability of plasma cell-free RNA (cfRNA) to reveal patterns of normal pregnancy progression and determine the risk of developing pre-eclampsia months before clinical presentation. Our results centre on comprehensive transcriptome data from eight independent prospectively collected cohorts comprising 1,840 racially diverse pregnancies and retrospective analysis of 2,539 banked plasma samples. The pre-eclampsia data include 524 samples (72 cases and 452 non-cases) from two diverse independent cohorts collected 14.5 weeks (s.d., 4.5 weeks) before delivery. We show that cfRNA signatures from a single blood draw can track pregnancy progression at the placental, maternal and fetal levels and can robustly predict pre-eclampsia, with a sensitivity of 75% and a positive predictive value of 32.3% (s.d., 3%), which is superior to the state-of-the-art method2. cfRNA signatures of normal pregnancy progression and pre-eclampsia are independent of clinical factors, such as maternal age, body mass index and race, which cumulatively account for less than 1% of model variance. Further, the cfRNA signature for pre-eclampsia contains gene features linked to biological processes implicated in the underlying pathophysiology of pre-eclampsia.

Preventing and Mitigating Radiology System Failures: A Guide to Disaster Planning

Disaster planning is a core facet of modern health care practice. Owing to complex infrastructure requirements, radiology departments are vulnerable to system failures that may occur in isolation or during a disaster event when the urgency for and volume of imaging examinations increases. Planning for systems failures helps ensure continuity of service provision and patient care during an adverse event. Hazards to which a radiology department is vulnerable can be identified by applying a systematic approach with recognized tools such as the Hazard, Risk, and Vulnerability Analysis. Potential critical weaknesses within the department are highlighted by the Failure Mode and Effects Analysis tool. Recognizing the potential latent conditions and active failures that may impact systems allows implementation of strategies to prevent failure or to build resilience and mitigate the effects if they happen. Inherent system resilience to an adverse event can be estimated, and the ability of a department to operate during a disaster and the subsequent recovery can be predicted. The main systems at risk in a radiology department are staff, structure, stuff (supplies and/or equipment), and software, although individual issues and solutions within these are department specific. When medical imaging or examination interpretation needs cannot be met in the radiology department, the use of portable imaging modalities and teleradiology can augment the disaster response. All phases of disaster response planning should consider both sustaining operations and the transition back to normal function. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Design of functionalised circular tandem repeat proteins with longer repeat topologies and enhanced subunit contact surfaces

Circular tandem repeat proteins (‘cTRPs’) are de novo designed protein scaffolds (in this and prior studies, based on antiparallel two-helix bundles) that contain repeated protein sequences and structural motifs and form closed circular structures. They can display significant stability and solubility, a wide range of sizes, and are useful as protein display particles for biotechnology applications. However, cTRPs also demonstrate inefficient self-assembly from smaller subunits. In this study, we describe a new generation of cTRPs, with longer repeats and increased interaction surfaces, which enhanced the self-assembly of two significantly different sizes of homotrimeric constructs. Finally, we demonstrated functionalization of these constructs with (1) a hexameric array of peptide-binding SH2 domains, and (2) a trimeric array of anti-SARS CoV-2 VHH domains. The latter proved capable of sub-nanomolar binding affinities towards the viral receptor binding domain and potent viral neutralization function.

Jazmine Hallinan et al. report the development of a new generation of circular tandem repeat proteins with enhanced self-assembly. Functionalisation of these constructs with SARS CoV-2 VHH domains resulted in sub-nanomolar binding affinity to the viral receptor binding domain.

An exploratory study of white blood cell proportions across preeclamptic and normotensive pregnancy by self-identified race in individuals with overweight or obesity

Objective: Examine white blood cell (WBC) proportions across preeclamptic (n = 28 cases) and normotensive (n = 28 controls) pregnancy in individuals with overweight/obesity.Methods: WBC proportions were inferred from genome-wide DNA methylation data and compared by case/control status and self-identified race.Results: In Trimester 1, ean B cell proportions were suggestively lower in cases in the overall sample and significantly lower in White participants but not in Black participants. More significant WBC proportion changes were observed across normotensive than preeclamptic pregnancy.Conclusions: These findings in a small sample demonstrate need for additional studies investigating the relationship between self-identified race and WBCs in pregnancy.

The Effect of Calcium Supplementation on Body Weight Before and During Pregnancy in Women Enrolled in the WHO Calcium and Preeclampsia Trial

INTRODUCTION

Obesity is a major and challenging public health problem. The aim of this substudy is to evaluate the effect of calcium supplementation on body weight in women recruited in the Calcium and Preeclampsia trial.

METHODS

Women were recruited before pregnancy and randomized to receive a calcium supplement containing 500 mg of elemental calcium or placebo until 20 weeks' gestation; all women received 1.5 g from 20 weeks until delivery.

RESULTS

A total of 630 women conceived during the study, 322 allocated to calcium and 308 to placebo. Among these, 230 allocated to calcium and 227 allocated to placebo had information on body weight at baseline and at 8 weeks' gestation. During the study period, women allocated to calcium had a mean weight increase of 1.1 (SD ±5.5) kg, whereas those allocated to placebo had a mean increase of 1.5 (SD ±6.1) kg, a mean difference of 0.4 kg (95% -0.4 (-1.4 to 0.6); P = .408). Women classified as obese at the start of the trial had a lower body weight gain at 8 weeks' gestation (1.0 kg; 95% CI: -3.2 to 1.2; P = .330) and at 32 weeks' gestation (2.1 kg; 95% CI: 5.6-1.3; P = .225) if they received calcium as compared to placebo. However, none of these differences were statistically significant.

CONCLUSION

The smaller increase in body weight found in women supplemented with 500 mg elemental calcium daily is quantitatively consistent with previous studies. However, in this study, the difference was not statistically significant.

The Global Pregnancy Collaboration (CoLab) Biobank of rare placentas

Many adverse pregnancy outcomes are the result of placental disorders. It has been difficult to decipher the root cause of many of these disorders due to an overlap in identifiable placental pathology and pregnancy outcomes. The reason for this confusion may be related to the lack of an appropriate control placenta. An ideal control placenta that is not related to adverse pregnancy outcomes is rare. We propose our pooled database at the Global Pregnancy Collaboration (CoLab) could be a solution for researchers.

Using the Goldilocks Principle to model coral ecosystem engineering

The occurrence and proliferation of reef-forming corals is of vast importance in terms of the biodiversity they support and the ecosystem services they provide. The complex three-dimensional structures engineered by corals are comprised of both live and dead coral, and the function, growth and stability of these systems will depend on the ratio of both. To model how the ratio of live : dead coral may change, the ‘Goldilocks Principle’ can be used, where organisms will only flourish if conditions are ‘just right’. With data from particle imaging velocimetry and numerical smooth particle hydrodynamic modelling with two simple rules, we demonstrate how this principle can be applied to a model reef system, and how corals are effectively optimizing their own local flow requirements through habitat engineering. Building on advances here, these approaches can be used in conjunction with numerical modelling to investigate the growth and mortality of biodiversity supporting framework in present-day and future coral reef structures.

Ultrasound for Suspected Acute Appendicitis in Adult Women Under Age 40: An Evaluation of On-Call Radiology Resident Scanning

RATIONALE AND OBJECTIVES

At our institution, on-call radiology residents perform emergent ultrasounds (US) outside of departmental working hours. The aim of the study was to evaluate radiology resident-performed US for clinically suspected acute appendicitis in women under the age of 40.

MATERIALS AND METHODS

Retrospective review of 104 consecutive US scans outside of departmental working hours by radiology residents, and 104 consecutive US studies scanned during departmental working hours by sonographers, in women under the age of 40 for clinically suspected appendicitis .

RESULTS

Appendix visualization rate was 27% for the resident group (sonographer group: 30%, p = 0.759). The sensitivity and specificity of US for appendicitis were 63% (95% confidence interval: 41%-81%) and 98% (95% CI: 91%-100%), respectively for the resident group (sonographer group: 69% [95% CI: 41%-89 %] and 98% [95% CI: 92%-100%], respectively). An alternative cause for right lower quadrant pain was offered in 17% of resident group cases (sonographer group: 21%, p = 0.598). Follow-up CT or MRI was performed in 47% of resident cases (sonographer group: 44%, p = 0.781). Residents performed more focused US (i.e. not imaging the pelvic organs), at 34% (sonographer group: 1%, p < 0.001). When only focused scanning was performed by residents, there was a trend toward increased downstream imaging (CT or MRI), odds ratio = 2.76 (95% CI: 0.99-7.70).

CONCLUSIONS

Out-of-hours US scans performed by radiology residents had similar performance characteristics compared to departmental sonographers. We discovered an increased rate of downstream imaging in cases in which residents performed limited scans and did not document visualization of the pelvic organs.

An Exploratory Study of Epigenetic Age in Preeclamptic and Normotensive Pregnancy Reveals Differences by Self-Reported Race but Not Pregnancy Outcome

Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality. Chronological age and race are associated with preeclampsia, but the role of these factors is not entirely understood. We hypothesized that DNA methylation age, a measure of biological age, would be higher in individuals with preeclampsia than in individuals with normotensive pregnancy and that DNA methylation age would differ by race across pregnancy. This was a longitudinal, exploratory study of 56 pregnant individuals (n = 28 preeclampsia cases and n = 28 normotensive controls). Genome-wide DNA methylation data were generated from trimester-specific peripheral blood samples. DNA methylation age was estimated using the "Improved Precision" clock, and ∆age, the difference between DNA methylation age and chronological age, was computed. DNA methylation age was compared with chronological age using Pearson correlations. The relationships between ∆age and preeclampsia status, self-reported race, and covariates were tested using multiple linear regression and performed both with and without consideration of cell-type heterogeneity. We observed strong correlation between chronological age and DNA methylation age across pregnancy, with significantly stronger correlation observed in White participants than in Black participants. We observed no association between ∆age and preeclampsia status. However, ∆age was higher in participants with higher pre-pregnancy body mass index in trimester 1 and lower in Black participants than in White participants in trimesters 2 and 3. Observations were largely consistent when controlling for cell-type heterogeneity. Our findings in a small sample support the need for additional studies to investigate the relationship between race and biological age, which could provide further insight into racial disparities across pregnancy. However, this study does not support an association between ∆age and preeclampsia status.

Tricuspid annular plane systolic excursion for the evaluation of right ventricular function in functional cardiac CT compared to MRI

AIM

To compare ejection fraction estimated by tricuspid annular plane systolic excursion (TAPSE) using cardiac computed tomography (CT) and cardiac magnetic resonance imaging (MRI) to the non-invasive reference standard, volumetric quantification of right ventricular ejection fraction (RVEF) by cardiac magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Thirty-one patients, who had undergone functional cardiac CT angiogram and cardiac MRI within 12 months, were evaluated retrospectively. Right ventricular (RV) volumes were processed using automated cardiac analysis software for CT, and manually processed by Simpson's method for MRI. MR-TAPSE was defined as the difference in length between two separate reference lines drawn at end diastole and end systole from the lateral tricuspid annulus to the right ventricular apex measured on four-chamber CINE images. CT-TAPSE was determined in an analogous manner on four-chamber reformatted images.

RESULTS

MR-TAPSE correlated moderately with MR-RVEF, (r=0.57, p<0.001). CT-TAPSE was found to correlate moderately well with MR-RVEF (r=0.58, p<0.001) and CT-RVEF (r=0.63, p<0.001). Bland-Altman analysis repeated with various multiplication factors for CT-TAPSE and MR-RVEF, determined a multiplication factor of 2.7 resulted in the lowest bias (0.74%).

CONCLUSION

CT-TAPSE is an easily obtainable parameter of RV function and is correlated with CT-RVEF and MR-RVEF. It can function as a quick check to rapidly validate CT right volumetry and estimate MR-RVEF.

Subtypes of Preeclampsia: Recognition and Determining Clinical Usefulness

The concept that preeclampsia is a multisystemic syndrome is appreciated in both research and clinical care. Our understanding of pathophysiology recognizes the role of inflammation, oxidative and endoplasm reticulum stress, and angiogenic dysfunction. Yet, we have not progressed greatly toward clinically useful prediction nor had substantial success in prevention or treatment. One possibility is that the maternal syndrome may be reached through different pathophysiological pathways, that is, subtypes of preeclampsia, that in their specificity yield more clinical utility. For example, early and late onset preeclampsia are increasingly acknowledged as different pathophysiological processes leading to a common presentation. Other subtypes of preeclampsia are supported by disparate clinical outcomes, long-range prognosis, organ systems involved, and risk factors. These insights have been supplemented by discovery-driven methods, which cluster preeclampsia cases into groups indicating different pathophysiologies. In this presentation, we review likely subtypes based on current knowledge and suggest others. We present a consideration of the requirements for a clinically meaningful preeclampsia subtype. A useful subtype should (1) identify a specific pathophysiological pathway or (2) specifically indicate maternal or fetal outcome, (3) be recognizable in a clinically useful time frame, and (4) these results should be reproducible and generalizable (but at varying frequency) including in low resource settings. We recommend that the default consideration be that preeclampsia includes several subtypes rather than trying to force all cases into a single pathophysiological pathway. The recognition of subtypes and deciphering their different pathophysiologies will provide specific targets for prevention, prediction, and treatment directing personalized care.

The effect of calcium supplementation on blood pressure in non-pregnant women with previous pre-eclampsia: A randomized placebo-controlled study

BACKGROUND

Low dietary calcium is associated with the hypertensive disorders of pregnancy, and evidence suggests that the risks associated with pre-eclampsia are reduced by calcium supplementation. In the general (non-pregnant) population, low dietary calcium intake is associated with hypertension with inconsistent evidence that calcium supplementation may reduce blood pressure. Women with pre-eclampsia are also at risk of hypertension later in life. An exploratory sub-study among early participants enrolled in the WHO long-term calcium supplementation in women at high risk of pre-eclampsia (CAP) study reported a trend to more blood pressure reduction with calcium in non-pregnant women with previous severe as opposed to non-severe pre-eclampsia. The current study reports the effects of low-dose calcium supplementation in non-pregnant women in the complete trial cohort.

METHODS

The CAP Study was a multi-country randomized, double-blind placebo-controlled clinical trial to test the hypothesis that calcium deficiency may play a role in the genesis of pre-eclampsia in early pregnancy. From 2011 to 2016, non-pregnant women who had pre-eclampsia or eclampsia in their most recent pregnancy were randomized to receive either 500 mg/day elemental calcium or placebo. In this sub-study we compared the change in blood pressure from baseline to the 12-week visit between participants receiving calcium versus placebo for those not pregnant at the 12-week visit.

RESULTS

Of 1355 women randomized, 810 attended a 12-week visit without being pregnant, of whom 791 had blood pressure measurements available for both baseline and 12-week visits. There was a greater reduction in blood pressure in the calcium group compared with the placebo group for systolic pressure (difference 3.1 mmHg, 95% CI 0.8 to 5.4) and mean arterial pressure (MAP) (difference 2.0 mmHg, 95% CI 0.1 to 3.8). The difference in diastolic blood pressure reduction (1.4 mmHg, 95% CI -0.5 to 3.3) was not statistically significant (p = 0.140). For women with previous pre-eclampsia with severe features (n = 447), there was significantly greater reduction in blood pressure in the calcium than the placebo group (difference for systolic 4.0, 95% CI 0.7 to 7.3; diastolic 3.0, 95% CI 0.5 to 5.5 and mean arterial pressure 3.3, 95% CI 0.8 to 5.9 mmHg). For women with previous pre-eclampsia without severe features (n = 344), there were no significant differences between calcium and placebo groups. ANOVA analysis found no statistically significant interaction between previous pre-eclampsia severity and treatment, for systolic (p = 0.372), diastolic (p = 0.063) or mean blood pressure (p = 0.103).

CONCLUSIONS

Low-dose calcium supplementation significantly reduced systolic and mean arterial pressure in non-pregnant women with previous pre-eclampsia. We did not confirm a greater calcium effect in women with previous pre-eclampsia with severe versus non-severe features. The effect of low-dose calcium is of importance since even modest blood pressure reductions at a population level may have important benefits in terms of reduced major complications of hypertension. This study adds to the mounting evidence of health benefits which could be achieved for populations with low dietary calcium through strategies to increase calcium intake, particularly among women at high risk due to previous pre-eclampsia.

CLINICAL TRIAL REGISTRATION

The trial was registered with the Pan-African Clinical Trials Registry, registration number PACTR201105000267371 (https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=267).

Unusual Near-Horizon Cosmic-Ray-like Events Observed by ANITA-IV

ANITA's fourth long-duration balloon flight in 2016 detected 29 cosmic-ray (CR)-like events on a background of 0.37_{-0.17}^{+0.27} anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous noninverted polarity, a p=5.3×10^{-4} chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply upcoming anomalous events similar to the two such events seen in prior flights.

Contrasting Reactive Organic Carbon Observations in the Southeast United States (SOAS) and Southern California (CalNex)

Despite the central role of reactive organic carbon (ROC) in the formation of secondary species that impact global air quality and climate, our assessment of ROC abundance and impacts is challenged by the diversity of species that contribute to it. We revisit measurements of ROC species made during two field campaigns in the United States: the 2013 SOAS campaign in forested Centreville, AL, and the 2010 CalNex campaign in urban Pasadena, CA. We find that average measured ROC concentrations are about twice as high in Pasadena (73.8 μgCsm^-3) than in Centreville (36.5 μgCsm^-3). However, the OH reactivity (OHR) measured at these sites is similar (20.1 and 19.3 s^-1). The shortfall in OHR when summing up measured contributions is 31%, at Pasadena and 14% at Centreville, suggesting that there may be a larger reservoir of unmeasured ROC at the former site. Estimated O₃ production and SOA potential (defined as concentration × yield) are both higher during CalNex than SOAS. This analysis suggests that the ROC in urban California is less reactive, but due to higher concentrations of oxides of nitrogen and hydroxyl radicals, is more efficient in terms of O₃ and SOA production, than in the forested southeastern U.S.

DNA Methylation of Endoglin Pathway Genes in Pregnant Women With and Without Preeclampsia

Objective

We compared blood-based DNA methylation levels of endoglin (ENG) and transforming growth factor beta receptor 2 (TGFβR2) gene promoter regions between women with clinically-overt preeclampsia and women with uncomplicated, normotensive pregnancies.

Methods

We used EpiTect Methyl II PCR Assays to evaluate DNA methylation of CpG islands located in promoter regions of ENG (CpG Island 114642) and TGFβR2 (CpG Island 110111). Preeclampsia was diagnosed based on blood pressure, protein, and uric acid criteria. N = 21 nulliparous preeclampsia case participants were 1:1 frequency matched to N = 21 nulliparous normotensive control participants on gestational age at sample collection (±2 weeks), smoking status, and labor status at sample collection. Methylation values were compared between case and control participant groups [(ENG subset: n = 20 (9 cases, 11 controls); TGFβR2 subset: n = 28 (15 cases, 13 controls)].

Results

The majority of the preeclampsia cases delivered at ⩾34 weeks' gestation (83%). Average methylation levels for ENG ([M ± (SD)]; Case Participant Group = 6.54% ± 4.57 versus Control Participant group = 4.81% ± 5.08; P = .102) and TGFβR2 (Case Participant Group = 1.50% ± 1.37 vs Control Participant Group = 1.70% ± 1.40; P = .695) promoter CpG islands did not differ significantly between the participant groups. Removal of 2 extreme outliers in the ENG analytic subset revealed a trend between levels of ENG methylation and pregnancy outcome (Case Participant Group = 5.17% ± 2.16 vs Control Participant Group = 3.36% ± 1.73; P = .062).

Conclusion

Additional epigenetic studies that include larger sample sizes, investigate preeclampsia subtypes, and capture methylation status of CpG island shores and shelves are needed to further inform us of the potential role that ENG and TGFβR2 DNA methylation plays in preeclampsia pathophysiology.

Soaking up the oil: Biological impacts of dispersants and crude oil on the sponge Halichondria panicea

Used during an oil spill to minimise the formation of an oil slick, dispersants have negative biological effects on marine model organisms. However, no study has investigated the impacts of dispersants on adult sponge individuals. Here, we examine the effects of water accommodated oil fraction (WAF - oil in seawater), chemically enhanced WAF (CEWAF - oil and dispersant in seawater) and Benzo[A]Pyrene on sponge Halichondria panicea at physiological and molecular levels. Sponge clearance rate decreased sharply when exposed to WAF and CEWAF but the oil loading at which the clearance rate was reduced by 50% (ED50) was 39-fold lower in CEWAF than in WAF. Transcriptomic analysis revealed a homogenous molecular response with the greatest number of differentially expressed genes identified in CEWAF samples (1,461 genes). Specifically, genes involved in stress responses were up-regulated. This study presents evidence that the use of dispersants should be considered carefully in areas where sponges are present.

Radiological-pathological correlation of subsolid pulmonary nodules: A single centre retrospective evaluation of the 2011 IASLC adenocarcinoma classification system

INTRODUCTION

The 2011 IASLC classification system proposes guidelines for radiologists and pathologists to classify adenocarcinomas spectrum lesions as preinvasive, minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IA). IA portends the worst clinical prognosis, and the imaging distinction between MIA and IA is controversial.

MATERIALS AND METHODS

Subsolid pulmonary nodules resected by microcoil localization over a three-year period were retrospectively reviewed by three chest radiologists and a pulmonary pathologist. Nodules were classified radiologically based on preoperative computed tomography (CT), with the solid nodule component measured on mediastinal windows applied to high-frequency lung kernel reconstructions, and pathologically according to 2011 IASLC criteria. Radiology interobserver and radiological-pathological variability of nodule classification, and potential reasons for nodule classification discordance were assessed.

RESULTS

Seventy-one subsolid nodules in 67 patients were included. The average size of invasive disease focus at histopathology was 5 mm (standard deviation 5 mm). Radiology interobserver agreement of nodule classification was good (Cohen's Kappa = 0.604, 95 % CI: 0.447 to 0.761). Agreement between consensus radiological interpretation and pathological category was fair (Cohen's Kappa = 0.236, 95 % CI: 0.054-0.421). Radiological and pathological nodule classification were concordant in 52 % (37 of 71) of nodules. The IASLC proposed CT solid component cut-off of 5 mm to distinguish MIA and IA yielded a sensitivity of 59 % and specificity of 80 %. Common reasons for nodule classification discordance included multiple solid components within a nodule on CT, scar and stromal collapse at pathology, and measurement variability.

CONCLUSION

Solid component(s) within persistent part-solid pulmonary nodules raise suspicion for invasive adenocarcinoma. Preoperative imaging classification is frequently discordant from final pathology, reflecting interpretive and technical challenges in radiological and pathological analysis.

Placental Growth Factor as an Indicator of Maternal Cardiovascular Risk After Pregnancy

BACKGROUND

Angiogenic placental growth factor (PlGF) concentrations rise during pregnancy, peaking at the end of midpregnancy. Low PlGF concentrations during pregnancy are associated with pregnancy complications with recognized later-life cardiovascular risk. We hypothesized that low PlGF concentrations, especially in midpregnancy, identify not only a subset of women at risk for pregnancy complications but also women with greater cardiovascular risk factor burden after pregnancy regardless of pregnancy outcome.

METHODS

In a population-based prospective cohort study of 5475 women, we computed gestational age-adjusted multiples of the medians of early pregnancy and midpregnancy PlGF concentrations. Information on pregnancy complications (preeclampsia, small for gestational age, and spontaneous preterm birth) was obtained from hospital registries. Six years after pregnancy, we measured maternal systolic and diastolic blood pressures, cardiac structure (aortic root diameter, left atrial diameter, left ventricular mass, and fractional shortening), carotid-femoral pulse wave velocity, and central retinal arteriolar and venular calibers. Blood pressure was also measured 9 years after pregnancy.

RESULTS

Women were on average 29.8 (SD, 5.2) years of age in pregnancy, were mostly European (55.2%), and 14.8% developed a pregnancy complication. Quartile analysis showed that especially women with midpregnancy PlGF in the lowest quartile (the low-PlGF subset) had a larger aortic root diameter (0.40 mm [95% CI, 0.08-0.73]), left atrial diameter (0.34 mm [95% CI, -0.09 to 0.78]), left ventricular mass (4.6 g [95% CI, 1.1-8.1]), and systolic blood pressure (2.3 mm Hg [95% CI, 0.93-3.6]) 6 years after pregnancy than women with the highest PlGF. Linear regression analysis showed that higher midpregnancy PlGF concentrations were associated with a smaller aortic root diameter (-0.24 mm [95% CI, -0.39 to -0.10]), smaller left atrial diameter (-0.75 mm [95% CI, -0.95 to -0.56]), lower left ventricular mass (-3.9 g [95% CI, -5.5 to -2.3]), and lower systolic blood pressure (-1.1 mm Hg [95% CI, -1.7 to -0.46]). These differences persisted after the exclusion of women with complicated pregnancies.

CONCLUSIONS

Women with low PlGF in midpregnancy have a greater aortic root diameter, left atrial diameter, and left ventricular mass and higher systolic blood pressure 6 and 9 years after pregnancy compared to women with higher PlGF, including women with uncomplicated pregnancies. The pathophysiological implications of lower PlGF concentrations in midpregnancy might provide insight into the identification of pathways contributing to greater cardiovascular risk factor burden.

Prevalence and associations of larger burden of intra-anal high-grade squamous intraepithelial lesions at baseline in an Australian cohort of gay and bisexual men: The Study of the Prevention of Anal Cancer

OBJECTIVES

To investigate factors associated with larger burden of intra-anal high-grade squamous intraepithelial lesions (HSIL) in a natural history study of HSIL.

METHODS

617 gay and bisexual men (GBM) attended a baseline visit. High-resolution anoscopy-directed biopsy was performed of suspected HSIL. GBM with biopsy-confirmed HSIL (bHSIL) affecting a single-octant were compared with those who had bHSIL affecting a larger area.

RESULTS

Of 196 men with bHSIL at baseline, 73 (37.2 %) had larger bHSIL burden. Larger burden was independently associated with anal HPV16 detection (aOR 2.06, 95 % CI 1.09-3.89, p = 0.026) and infection with a greater number of high-risk HPV types (aOR per type increase 1.25, 95 % CI 1.05-1.49, p-trend = 0.010).

CONCLUSION

The observation that men with a larger burden of HSIL also had more risk factors for anal cancer suggests this group may warrant closer observation to ensure earlier detection, and thus improved prognosis, of individuals whose HSIL may progress to anal cancer.

Investigating Maternal Brain Alterations in Preeclampsia: the Need for a Multidisciplinary Effort

PURPOSE OF REVIEW

To provide insight into the mechanisms underlying cerebral pathophysiology and to highlight possible methods for evaluation, screening, and surveillance of cerebral complications in preeclampsia.

RECENT FINDINGS

The pathophysiology of eclampsia remains enigmatic. Animal studies show that the cerebral circulation in pregnancy and preeclampsia might be affected with increased permeability over the blood-brain barrier and altered cerebral blood flow due to impaired cerebral autoregulation. The increased blood pressure cannot be the only underlying cause of eclampsia and cerebral edema, since some cases of eclampsia arise without simultaneous hypertension. Findings from animal studies need to be confirmed in human tissues. Evaluation of brain alterations in preeclampsia and eclampsia is challenging and demands a multidisciplinary collaboration, since no single method can accurately and fully describe how preeclampsia affects the brain. Cerebral complications of preeclampsia are significant factors in maternal morbidity and mortality worldwide. No single method can accurately describe the full picture of how preeclampsia affects the brain vasculature and parenchyma. We recommend an international and multidisciplinary effort not only to overcome the issue of limited sample availability but also to optimize the quality of research.

Pre-eclampsia: pathophysiology and clinical implications

Pre-eclampsia is a common disorder that particularly affects first pregnancies. The clinical presentation is highly variable but hypertension and proteinuria are usually seen. These systemic signs arise from soluble factors released from the placenta as a result of a response to stress of syncytiotrophoblast. There are two sub-types: early and late onset pre-eclampsia, with others almost certainly yet to be identified. Early onset pre-eclampsia arises owing to defective placentation, whilst late onset pre-eclampsia may center around interactions between normal senescence of the placenta and a maternal genetic predisposition to cardiovascular and metabolic disease. The causes, placental and maternal, vary among individuals. Recent research has focused on placental-uterine interactions in early pregnancy. The aim now is to translate these findings into new ways to predict, prevent, and treat pre-eclampsia.

On the sources and sinks of atmospheric VOCs: an integrated analysis of recent aircraft campaigns over North America

We apply a high-resolution chemical transport model (GEOS-Chem CTM) with updated treatment of volatile organic compounds (VOCs) and a comprehensive suite of airborne datasets over North America to (i) characterize the VOC budget and (ii) test the ability of current models to capture the distribution and reactivity of atmospheric VOCs over this region. Biogenic emissions dominate the North American VOC budget in the model, accounting for 70 % and 95 % of annually emitted VOC carbon and reactivity, respectively. Based on current inventories anthropogenic emissions have declined to the point where biogenic emissions are the dominant summertime source of VOC reactivity even in most major North American cities. Methane oxidation is a 2x larger source of nonmethane VOCs (via production of formaldehyde and methyl hydroperoxide) over North America in the model than are anthropogenic emissions. However, anthropogenic VOCs account for over half of the ambient VOC loading over the majority of the region owing to their longer aggregate lifetime. Fires can be a significant VOC source episodically but are small on average. In the planetary boundary layer (PBL), the model exhibits skill in capturing observed variability in total VOC abundance (R 2 = 0:36) and reactivity (R 2 = 0:54). The same is not true in the free troposphere (FT), where skill is low and there is a persistent low model bias (~ 60 %), with most (27 of 34) model VOCs underestimated by more than a factor of 2. A comparison of PBL: FT concentration ratios over the southeastern US points to a misrepresentation of PBL ventilation as a contributor to these model FT biases. We also find that a relatively small number of VOCs (acetone, methanol, ethane, acetaldehyde, formaldehyde, isoprene C oxidation products, methyl hydroperoxide) drive a large fraction of total ambient VOC reactivity and associated model biases; research to improve understanding of their budgets is thus warranted. A source tracer analysis suggests a current overestimate of biogenic sources for hydroxyacetone, methyl ethyl ketone and glyoxal, an underestimate of biogenic formic acid sources, and an underestimate of peroxyacetic acid production across biogenic and anthropogenic precursors. Future work to improve model representations of vertical transport and to address the VOC biases discussed are needed to advance predictions of ozone and SOA formation.

Risk of Ischemic Placental Disease in Relation to Family History of Preeclampsia

OBJECTIVE

To assess the risk of ischemic placental disease (IPD) including preeclampsia, small for gestational age (SGA), and abruption, in relation to preeclampsia in maternal grandmother, mother, and sister(s).

STUDY DESIGN

We performed a secondary analysis of data from a randomized trial of vitamins C and E for preeclampsia prevention. Data on family history of preeclampsia were based on recall by the proband. The associations between family history of preeclampsia and the odds of IPD were evaluated from alternating logistic regressions.

RESULTS

Of the 9,686 women who delivered nonmalformed, singleton live births, 17.1% had IPD. Probands provided data on preeclampsia in 55.5% (n = 5,374) on all three family members, 26.5% (n = 2,562) in mother and sister(s) only, and 11.6% (n = 1,125) in sister(s) only. The pairwise odds ratio (pOR) of IPD was 1.16 (95% confidence interval [CI]: 1.00-1.36) if one or more of the female relatives had preeclampsia. The pORs of preeclampsia were 1.54 (95% CI: 1.12-2.13) and 1.35 (95% CI: 1.03-1.77) if the proband's mother or sister(s) had a preeclamptic pregnancy, respectively, but no associations were seen for SGA infant or abruption.

CONCLUSION

This study suggests that IPD may share a predisposition with preeclampsia, suggesting a familial inheritance.

Estrogen metabolism pathways in preeclampsia and normal pregnancy

Experimental studies suggest that shallow uterine cytotrophoblastic invasion in preeclampsia may be associated with alterations in estrogen metabolism. The objective of this study was to examine the association of parent estrogens and their metabolites between preeclamptics and normotensive controls at three time points during pregnancy. Methods Parent estrogens and their metabolites were measured in urine by high-performance liquid chromatography-tandem mass spectrometry in 66 singleton preeclampsia cases and 137 matched controls. Percent change in geometric means were estimated by general linear models adjusted for gestational age at sampling, maternal age, parity, race, body mass index, and use of assisted reproductive technologies. Results Urinary estradiol concentrations were approximately 50% higher in early pregnancy in preeclampsia cases than controls, but similar late in pregnancy. There was an approximate 20% reduction in total 2-pathway metabolites and 4-pathway metabolites in cases compared with controls in mid- and later pregnancy that was slightly attenuated with adjustment for BMI, and a reduction in 16-pathways in mid-pregnancy but not later. Conclusion(s) Our findings show that estradiol concentrations were elevated in preeclampsia versus controls in early pregnancy. In mid-pregnancy, all three estrogen metabolism (2-, 4-, and 16-) pathways showed some reduction in preeclampsia that appeared to continue for the 2- and 4-pathways in late pregnancy. We hypothesize that this may indicate that there is a generalized reduction in estrogen metabolism in preeclampsia rather than a deficit of specific enzymes, such as those involved in the 2-hydroxylation pathway.

Critical barriers for preeclampsia diagnosis and treatment in low-resource settings: An example from Bolivia

The goals of the United Nation's Millennium Summit for reducing maternal mortality have proven difficult to achieve. In Bolivia, where maternal mortality is twice the South American average, improving the diagnosis, treatment and ultimately prevention of preeclampsia is key for achieving targeted reductions. We held a workshop in La Paz, Bolivia to review recent revisions in the diagnosis and treatment of preeclampsia, barriers for their implementation, and means for overcoming them. While physicians are generally aware of current recommendations, substantial barriers exist for their implementation due to geographic factors increasing disease prevalence and limiting health-care access, cultural and economic factors affecting the care provided, and infrastructure deficits impeding diagnosis and treatment. Means for overcoming such barriers include changes in the culture of health care, use of standardized diagnostic protocols, the adoption of low-cost technologies for improving the diagnosis and referral of preeclamptic cases to specialized treatment centers, training programs to foster multidisciplinary team approaches, and efforts to enhance local research capacity. While challenging, the synergistic nature of current barriers for preeclampsia diagnosis and treatment also affords opportunities for making far-reaching improvements in maternal, infant and lifelong health.