A Counterfactual Analysis of Impact of Cesarean Birth in a First Birth on Severe Maternal Morbidity in the Subsequent Birth.

BACKGROUND: It is known that cesarean birth affects maternal outcomes in subsequent pregnancies, but specific effect estimates are lacking. We sought to quantify the effect of cesarean birth reduction among nulliparous, term, singleton, vertex (NTSV) births (i.e., preventable cesarean births) on severe maternal morbidity (SMM) in the second birth. METHODS: We examined birth certificates linked with maternal hospitalization data (2007-19) from California for NTSV births with a second birth (N = 779,382). The exposure was cesarean delivery in first birth and the outcome was SMM in the second birth. We used adjusted Poisson regression models to calculate risk ratios and population attributable fraction for SMM in the second birth and conducted a counterfactual impact analysis to estimate how lowering NTSV cesarean births could reduce SMM in second birth. RESULTS: The adjusted risk ratio for SMM in the second birth given a prior cesarean birth was 1.7 (95% CI 1.5-1.9); 15.5% (95% CI 15.3%-15.7%) of this SMM may be attributable to prior cesarean birth. In a counterfactual analysis where 12% of the California population least likely to get a cesarean birth instead delivered vaginally, we observed 174 fewer SMM events in a population of individuals with a low-risk first birth and a subsequent birth. CONCLUSIONS: In our counterfactual analysis, lowering primary cesarean birth among a NTSV population was associated with fewer downstream SMM events in subsequent births and overall. Additionally, our findings reflect the importance of considering the cumulative accrual of risks across the reproductive life-course.

Uranium Speciation and Mobilization in Thawing Permafrost.

Uranium is a toxic and pervasive geogenic contaminant often associated with organic matter. Its abundance and speciation in organic-rich permafrost soils are unknown, thereby limiting our ability to assess risks associated with uranium mobilization during permafrost thaw. In this study, we assessed uranium speciation in permafrost soil and porewater liberated during thaw using active-layer and permafrost samples from a study area in Yukon, Canada where elevated uranium concentrations occur in bedrock and groundwater. Permafrost contained 1.1-28 wt % organic carbon and elevated uranium (range 7.6-1040 µg g-1, median 25 µg g-1) relative to local bedrock. The highest soil uranium concentrations were encountered in catchments hosting uranium-enriched bedrock and correlated positively with soil organic carbon. X-ray absorption spectroscopy, micro-X-ray fluorescence, and electron microscopy analyses revealed that solid-phase uranium predominantly occurs as uranium(VI) associated with soil organic matter. Extended X-ray absorption fine structure (EXAFS) analyses suggested the presence of uranium(VI) coordinated with carbon, consistent with bidentate-mononuclear uranyl complexation on carboxyl groups. Permafrost thaw produced circumneutral pH porewater (pH 6.2-7.5) with elevated dissolved uranium (0.5-203 µg L-1). Geochemical modeling indicated that calcium-uranyl-carbonate complexes dominated the dissolved uranium speciation. This study highlights that permafrost soil can mobilize uranium upon thaw and that uranium fate is linked to dynamic biogeochemical reactions involving organic carbon and groundwater chemistry.

The relative impact of labor induction versus improved labor management: Before and after the ARRIVE (a randomized trial of induction vs. expectant management) trial.

OBJECTIVE: To evaluate the association of labor induction on cesarean delivery and other maternal and neonatal outcomes in low-risk, full-term patients in community hospitals during a period of concerted effort to safely prevent cesarean delivery. METHODS: We performed a retrospective cohort study using the California Maternal Data Center comprised linked discharge diagnoses and birth certificate data for all low-risk, nulliparous, term, singleton, vertex (NTSV) individuals between 39 and 41 weeks from three Sacramento Valley community hospitals from 2016 to 2022 (N = 10,821) during a period of state-wide efforts to safely reduce cesarean rates. Logistic regression was used to calculate odds ratios (ORs) and adjusted odds ratios (aORs) after labor induction in two time periods before and after the ARRIVE trial. RESULTS: During the study period, labor induction increased from 14.7% to 23.1%. Controlling for maternal age, pre-pregnancy BMI, birthweight, maternal race and ethnicity, birthplace, English language, gestational age, Medicaid status, delivery year, and labor induction was associated with an increased aOR of 1.67 (95% CI 1.48-1.89) for cesarean delivery. We found a trend toward increased aOR of chorioamnionitis but no differences in blood transfusion, severe maternal morbidity, unexpected newborn complications, chorioamnionitis, operative vaginal delivery, maternal lacerations, and shoulder dystocia with labor induction. A decrease aOR of cesarean delivery was observed comparing all births in 2019-2021 to 2016-2018. CONCLUSION: Labor induction was associated with an increased aOR for cesarean delivery both before and after the ARRIVE trial. A decreased aOR for cesarean delivery was observed during the period of statewide efforts to safely reduce cesarean delivery both with and without labor induction.

Trends and Disparities in Severe Maternal Morbidity Indicator Categories during Childbirth Hospitalization in California from 1997 to 2017.

OBJECTIVE: Severe maternal morbidity (SMM) is increasing and characterized by substantial racial and ethnic disparities. Analyzing trends and disparities across time by etiologic or organ system groups instead of an aggregated index may inform specific, actionable pathways to equitable care. We explored trends and racial and ethnic disparities in seven SMM categories at childbirth hospitalization. STUDY DESIGN: We analyzed California birth cohort data on all live and stillbirths ≥ 20 weeks' gestation from 1997 to 2017 (n = 10,580,096) using the Centers for Disease Control and Prevention's SMM index. Cases were categorized into seven nonmutually exclusive indicator categories (cardiac, renal, respiratory, hemorrhage, sepsis, other obstetric, and other medical SMM). We compared prevalence and trends in SMM indicator categories overall and by racial and ethnic group using logistic and linear regression. RESULTS: SMM occurred in 1.16% of births and nontransfusion SMM in 0.54%. Hemorrhage SMM occurred most frequently (27 per 10,000 births), followed by other obstetric (11), respiratory (7), and sepsis, cardiac, and renal SMM (5). Hemorrhage, renal, respiratory, and sepsis SMM increased over time for all racial and ethnic groups. The largest disparities were for Black individuals, including over 3-fold increased odds of other medical SMM. Renal and sepsis morbidity had the largest relative increases over time (717 and 544%). Sepsis and hemorrhage SMM had the largest absolute changes over time (17 per 10,000 increase). Disparities increased over time for respiratory SMM among Black, U.S.-born Hispanic, and non-U.S.-born Hispanic individuals and for sepsis SMM among Asian or Pacific Islander individuals. Disparities decreased over time for sepsis SMM among Black individuals yet remained substantial. CONCLUSION: Our research further supports the critical need to address SMM and disparities as a significant public health priority in the United States and suggests that examining SMM subgroups may reveal helpful nuance for understanding trends, disparities, and potential needs for intervention. KEY POINTS: · By SMM subgroup, trends and racial and ethnic disparities varied yet Black individuals consistently had highest rates.. · Hemorrhage, renal, respiratory, and sepsis SMM significantly increased over time.. · Disparities increased for respiratory SMM among Black, U.S.-born Hispanic and non-U.S.-born Hispanic individuals and for sepsis SMM among Asian or Pacific Islander individuals..

Validation of ICD-10-CM Diagnosis Codes for Gestational Age at Birth.

BACKGROUND: The International Classification of Diseases , 10th Revision, Clinical Modification (ICD-10-CM) introduced diagnosis codes for week of gestation. Our objective was to assess the validity of these codes among live births, which could have major utility in perinatal research and quality improvement. METHODS: We used linked birth certificate and patient discharge data from births in California during 2016-2019 (N = 1,843,992). We identified gestational age using Z3A.xx ICD-10-CM diagnosis codes in birthing patient discharge data and compared it with the gold standard of obstetric estimate, as recorded on the birth certificate. We further assessed sensitivity and specificity of gestational age categories (≥37 weeks, <37 weeks, <32 weeks, <28 weeks), given these categories are frequently of interest, and evaluated differences in validity of preterm birth (<37 weeks' gestation) by patient characteristics. RESULTS: One-million seven-hundred seventy-thousand one-hundred three patients had a gestational age recorded in patient discharge and birth certificate data. When comparing gestational age in patient discharge data with birth certificate data, the concordance correlation coefficient was 0.96 (95% confidence interval [CI] = 0.96, 0.96) and the mean difference between the two measurements was 0.047 weeks (95% CI = 0.046, 0.047 weeks). Ninety-five percent of the differences between the two measurements were between -1.00 week and +1.09 weeks. Sensitivity and specificity were 0.94 to 1.00 for all gestational age categories and were 0.94 to 1.00 for preterm birth across sociodemographic groups. CONCLUSIONS: We found week-specific gestational age at delivery ICD-10-CM diagnosis codes in patient discharge data to have high validity when compared with the best obstetric estimate on the birth certificate.

Prevalence of Adenopathy at Chest Computed Tomography After Vaccination for Severe Acute Respiratory Syndrome Coronavirus 2.

OBJECTIVE: This study aimed to determine the prevalence of axillary and subpectoral (SP) lymph nodes after ipsilateral COVID-19 vaccine administration on chest computed tomography (CT). METHODS: Subjects with chest CTs between 2 and 25 days after a first or second vaccine dose, December 15, 2020, to February 12, 2021, were included. Orthogonal measures of the largest axillary and SP nodes were recorded by 2 readers blinded to vaccine administration and clinical details. A mean nodal diameter discrepancy of ≥6 mm between contralateral stations was considered positive for asymmetry. Correlation with the side of vaccination, using a Spearman rank correlation, was performed on the full cohort and after excluding patients with diseases associated with adenopathy. RESULTS: Of the 138 subjects (81 women, 57 men; mean [SD] age, 74.4 ± 11.7 years), 48 (35%) had asymmetrically enlarged axillary and/or SP lymph nodes, 42 (30%) had ipsilateral, and 6 (4%) had contralateral to vaccination ( P = 0.003). Exclusion of 29 subjects with conditions associated with adenopathy showed almost identical correlation, with asymmetric nodes in 32 of 109 (29%) ipsilateral and in 5 of 109 (5%) contralateral to vaccination ( P = 0.002). CONCLUSIONS: Axillary and/or SP lymph nodes ipsilateral to vaccine administration represents a clinical conundrum. Asymmetric nodes were detected at CT in 30% of subjects overall and 29% of subjects without conditions associated with adenopathy, approximately double the prevalence rate reported to the Centers for Disease Control and Prevention by vaccine manufacturers. When interpreting examinations correlation with vaccine administration timing and site is important for pragmatic management.

Measuring Variation in Interpregnancy Interval: Identifying Hotspots for Improvement Initiatives.

OBJECTIVE: The study aimed to determine if single year birth certificate data can be used to identify regional and hospital variation in rates of short interpregnancy interval (IPI < 6 months). STUDY DESIGN: IPI was estimated for multiparous women ages 15 to 44 years with singleton live births between 2015 and 2016. Perinatal outcomes, place of birth, maternal race, and data for IPI calculations were obtained by using birth certificates. IPI frequencies are presented as observed rates. RESULTS: The cohort included 562,039 multiparous women. Short IPI rates were similar to those obtained with analyses by using linked longitudinal data and confirmed the association with preterm birth. Short IPI rates varied by race and Hispanic nativity. There was substantial hospital (0.8-9%) and regional (2.9-6.2%) variation in short IPI rates. CONCLUSION: IPI rates can be reliably obtained from current year birth certificate data. This can be a useful tool for quality improvement projects targeting interventions and rapidly assessing their progress to promote optimal birth spacing. KEY POINTS: · Near-real time regional and hospital IPI rates can be reliably obtained from current year birth certificate data.. · Substantial variations in rates of short IPI exist between hospital and perinatal regions.. · IPI rates from individual birth certificates can be a tool to target and assess interventions..

Updated assessment of occupational safety and health hazards of climate change.

Workers, particularly outdoor workers, are among the populations most disproportionately affected by climate-related hazards. However, scientific research and control actions to comprehensively address these hazards are notably absent. To assess this absence, a seven-category framework was developed in 2009 to characterize the scientific literature published from 1988-2008. Using this framework, a second assessment examined the literature published through 2014, and the current one examines literature from 2014-2021. The objectives were to present literature that updates the framework and related topics and increases awareness of the role of climate change in occupational safety and health. In general, there is substantial literature on worker hazards related to ambient temperatures, biological hazards, and extreme weather but less on air pollution, ultraviolet radiation, industrial transitions, and the built environment. There is growing literature on mental health and health equity issues related to climate change, but much more research is needed. The socioeconomic impacts of climate change also require more research. This study illustrates that workers are experiencing increased morbidity and mortality related to climate change. In all areas of climate-related worker risk, including geoengineering, research is needed on the causality and prevalence of hazards, along with surveillance to identify, and interventions for hazard prevention and control.

An insect antifreeze protein from Anatolica polita enhances the cryoprotection of Xenopus laevis eggs and embryos.

Cryoprotection is of interest in many fields of research, necessitating a greater understanding of different cryoprotective agents. Antifreeze proteins have been identified that have the ability to confer cryoprotection in certain organisms. Antifreeze proteins are an evolutionary adaptation that contributes to the freeze resistance of certain fish, insects, bacteria and plants. These proteins adsorb to an ice crystal's surface and restrict its growth within a certain temperature range. We investigated the ability of an antifreeze protein from the desert beetle Anatolica polita, ApAFP752, to confer cryoprotection in the frog Xenopus laevis. Xenopus laevis eggs and embryos microinjected with ApAFP752 exhibited reduced damage and increased survival after a freeze-thaw cycle in a concentration-dependent manner. We also demonstrate that ApAFP752 localizes to the plasma membrane in eggs and embryonic blastomeres and is not toxic for early development. These studies show the potential of an insect antifreeze protein to confer cryoprotection in amphibian eggs and embryos.

Sexual and/or gender minority disparities in obstetrical and birth outcomes.

BACKGROUND: Many sexual and/or gender minority individuals build families through pregnancy and childbirth, but it is unknown whether they experience different clinical outcomes than those who are not sexual and/or gender minority individuals. OBJECTIVE: To evaluate obstetrical and birth outcomes comparing couples who are likely sexual and/or gender minority patients compared with those who are not likely to be sexual and/or gender minority patients. STUDY DESIGN: We performed a population-based cohort study of live birth hospitalizations during 2016 to 2019 linked to birth certificates in California. California changed its birth certificate in 2016 to include gender-neutral fields such as "parent giving birth" and "parent not giving birth," with options for each role to specify "mother," "father," or "parent." We classified birthing patients in mother-mother partnerships and those who identified as a father in any partnership as likely sexual and/or gender minority and classified birthing patients in mother-father partnerships as likely not sexual and/or gender minority. We used multivariable modified Poisson regression models to estimate the risk ratios for associations between likely sexual and/or gender minority parental structures and outcomes. The models were adjusted for sociodemographic factors, comorbidities, and multifetal gestation selected by causal diagrams. We replicated the analyses after excluding multifetal gestations. RESULTS: In the final birthing patient sample, 1,483,119 were mothers with father partners, 2572 were mothers with mother partners, and 498 were fathers with any partner. Compared with birthing patients in mother-father partnerships, birthing patients in mother-mother partnerships experienced significantly higher rates of multifetal gestation (adjusted risk ratio, 3.9; 95% confidence interval, 3.4-4.4), labor induction (adjusted risk ratio, 1.2; 95% confidence interval, 1.1-1.3), postpartum hemorrhage (adjusted risk ratio, 1.4; 95% confidence interval, 1.3-1.6), severe morbidity (adjusted risk ratio, 1.4; 95% confidence interval, 1.2-1.8), and nontransfusion severe morbidity (adjusted risk ratio, 1.4; 95% confidence interval, 1.1-1.9). Severe morbidity was identified following the Centers for Disease Control and Prevention "severe maternal morbidity" index. Gestational diabetes mellitus, hypertensive disorders of pregnancy, cesarean delivery, preterm birth (<37 weeks' gestation), low birthweight (<2500 g), and low Apgar score (<7 at 5 minutes) did not significantly differ in the multivariable analyses. No outcomes significantly differed between father birthing patients in any partnership and birthing patients in mother-father partnerships in either crude or multivariable analyses, though the risk of multifetal gestation was nonsignificantly higher (adjusted risk ratio, 1.5; 95% confidence interval, 0.9-2.7). The adjusted risk ratios for the outcomes were similar after restriction to singleton gestations. CONCLUSION: Birthing mothers with mother partners experienced disparities in several obstetrical and birth outcomes independent of sociodemographic factors, comorbidities, and multifetal gestation. Birthing fathers in any partnership were not at a significantly elevated risk of any adverse obstetrical or birth outcome considered in this study.

Society for Maternal-Fetal Medicine Special Statement: A quality metric for evaluating timely treatment of severe hypertension.

Severe hypertension in pregnancy is a medical emergency. Although expeditious treatment within 30 to 60 minutes is recommended to reduce the risk of maternal death or severe morbidity, treatment is often delayed by >1 hour. In this statement, we propose a quality metric that facilities can use to track their rates of timely treatment of severe hypertension. We encourage facilities to adopt this metric so that future reports from different facilities will be based on a uniform definition of timely treatment.

Designing and implementing methodology for double-blind, placebo-controlled clinical trials using blood products within the Department of Veterans Affairs.

BACKGROUND: Success in conducting clinical trials during the coronavirus disease of 2019 pandemic requires the ability to innovate and adapt. There are well-established procedures for the blinding of investigational agents, especially medications, in placebo-controlled randomized clinical trials within the Veterans Health Administration. However, these procedures, managed by research pharmacists, may not apply to investigational agents that are not exclusively managed by pharmacy, such as blood products, including coronavirus disease of 2019 convalescent plasma (plasma). In the absence of established blinding procedures, such studies require special design considerations to minimize uncertainty or bias. METHODS: We describe the processes and procedures developed for blinding of plasma in "Veterans Affairs CoronavirUs Research and Efficacy Studies-1" as a prototypical study using this class of investigational therapeutic agents. Veterans Affairs CoronavirUs Research and Efficacy Studies-1 is an ongoing multicenter randomized clinical trial testing the efficacy of plasma added to conventional therapy for severe acute respiratory syndrome coronavirus-2 infection. RESULTS: We report the design of procedures to supply investigational blood products or 0.9% normal saline (saline) control while ensuring the integrity of the blind. Key aspects include workflow considerations, physical blinding strategies, and methods for engaging stakeholders. These procedures leverage the well-established Veterans Affairs research pharmacist's research infrastructure, and Blood Bank Services, which is responsible for blood-based investigational products. CONCLUSION: By describing the methods used to deliver blood products in a blinded manner in Veterans Affairs CoronavirUs Research and Efficacy Studies-1, we strive both to educate and to increase awareness to improve the implementation of these biological therapeutics for future, high-quality research studies.

How State Perinatal Quality Collaboratives Can Improve Rural Maternity Care.

Perinatal Quality Collaboratives (PQCs) are now present in nearly all states and provide important tools and strategies for improving maternal outcomes. State PQCs can focus their strengths to address rural maternal health challenges using support groups of rural hospitals, of tertiary facilities that network with them, and of other PQCs to share best practices for rural hospitals to: (1) Support networks of care and telehealth; (2) Support remote education and training; (3) Implement rural appropriate versions of National Safety Bundles; (4) Engage and support providers beyond obstetricians; and (5) Engage community members and resources.

Working hours, sleep, and fatigue in the agriculture, forestry, and fishing sector: A scoping review.

INTRODUCTION: Agriculture, forestry, and fishing industry (AgFF) workers often work extremely long hours during peak production seasons, resulting in sleep deprivation and fatigue. The National Occupational Research Agenda has classified fatigue as a "significant safety issue" and area of concern for many industry sectors, including AgFF. This review explores current research and practice in AgFF and proposes next steps. METHODS: We conducted a scoping literature review to examine the extent and nature of research in this area. Article inclusion criteria included peer-reviewed journal articles written in English; published after 1989; covering AgFF workers in high-income countries; with data on working hours/schedules and sleep related to safety and health. RESULTS: Limited research has addressed long hours and sleep deprivation among AgFF workers. We identified 8350 articles for title and abstract review. Among those, 407 underwent full-text review and 96 met all inclusion criteria (67% agriculture, 25% fishing/seafood processing, 8% forestry). The literature provided some evidence fatigue contributes to fatalities, injuries, and illnesses in AgFF. Older, new, young, foreign-born, and female workers, as well as those who work in small organizations or longer hours (40+) may be at higher risk for fatigue-related injury and illness. Few studies have developed or evaluated interventions to control risks. DISCUSSION: Given that fatigue is a factor in injury and illness for this sector, future AgFF surveillance and research should increase efforts to capture fatigue and sleep data, directly investigate the role of long hours and nonstandard work schedules in the sector, and most importantly, create practical interventions to manage fatigue.

Culture That Facilitates Change: A Mixed Methods Study of Hospitals Engaged in Reducing Cesarean Deliveries.

PURPOSE: Large-scale efforts to reduce cesarean deliveries have shown varied levels of impact; yet understanding factors that contribute to hospitals' success are lacking. We aimed to characterize unit culture differences at hospitals that successfully reduced their cesarean rates compared with those that did not. METHODS: A mixed methods study of California hospitals participating in a statewide initiative to reduce cesarean delivery. Participants included nurses, obstetricians, family physicians, midwives, and anesthesiologists practicing at participating hospitals. Hospitals' net change in nulliparous, term, singleton, and vertex cesarean delivery rates classified them as successful if they achieved either a minimum 5 percentage point reduction or rate of fewer than 24%. The Labor Culture Survey was used to quantify differences in unit culture. Key informant interviews were used to explore quantitative findings and characterize additional cultural barriers and facilitators. RESULTS: Out of 55 hospitals, 37 (n = 840 clinicians) meeting inclusion criteria participated in the Labor Culture Survey. Physicians' individual attitudes differed by hospital success on 5 scales: best practices (P = .003), fear (P = .001), cesarean safety (P = .014), physician oversight (P <.001), and microculture (P = .044) scales. Patient ability to make informed decisions showed poor agreement across all hospitals, but was higher at successful hospitals (38% vs 29%, P = .01). Important qualitative themes included: ease of access to shared resources on best practices, fear of bad outcomes, personal resistance to change, collaborative practice and effective communication, leadership engagement, and cultural flexibility. CONCLUSIONS: Successful hospitals' culture and context was measurably different from nonresponders. Leveraging these contextual factors may facilitate success.

Geographic impact on access to care and survival for non-curative esophagogastric cancer: a population-based study.

BACKGROUND: Among patients not undergoing curative-intent therapy for esophagogastric cancer, access to care may vary. We examined the geographic distribution of care delivery and survival and their relationship with distance to cancer centres for non-curative esophagogastric cancer, hypothesising that patients living further from cancer centres have worse outcomes. METHODS: We conducted a population-based analysis of adults with non-curative esophagogastric cancer from 2005 to 2017 using linked administrative healthcare datasets in Ontario, Canada. Outcomes were medical oncology consultation, receipt of chemotherapy, and overall survival. Using geographic information system analysis, we mapped locations of cancer centres and outcomes across census divisions. Bivariate choropleth maps identified regional outcome discordances. Multivariable regression models assessed the relationship between distance from patient residence to the nearest cancer centre and outcomes, adjusting for demographic, clinical, and socioeconomic factors. RESULTS: Of 10,228 patients surviving a median 5.1 months (IQR: 2.0-12.0), 68.5% had medical oncology consultation and 32.2% received chemotherapy. Certain distances (reference ≤ 10 km) were associated with lower consultation [relative risk 0.79 (95% CI 0.63-0.97) for ≥ 101 km], chemotherapy receipt [relative risk 0.67 (95% CI 0.53-0.85) for ≥ 101 km], and overall survival [hazard ratio 1.07 (95% CI 1.02-1.13) for 11-50 km, hazard ratio 1.13 (95% CI 1.04-1.23) for 51-100 km]. CONCLUSION: A third of patients did not see medical oncology and most did not receive chemotherapy. Outcomes exhibited high geographic variability. Location of residence influenced outcomes, with inferior outcomes at certain distances > 10 km from cancer centres. These findings are important for designing interventions to reduce access disparities for non-curative esophagogastric cancer care.

Chest CT Angiography for Acute Aortic Pathologic Conditions: Pearls and Pitfalls.

Chest CT angiography (CTA) is essential in the diagnosis of acute aortic syndromes. Chest CTA quality can be optimized with attention to technical parameters pertaining to noncontrast imaging, timing of contrast-enhanced imaging, contrast material volume, kilovolt potential, tube-current modulation, and decisions regarding electrocardiographic-gating and ultra-fast imaging, which may affect the accurate diagnosis of acute aortic syndromes. An understanding of methods to apply to address suboptimal image quality is useful, as the accurate identification of acute aortic syndromes is essential for appropriate patient management. Acute aortic syndromes have high morbidity and mortality, particularly when involving the ascending aorta, and include classic aortic dissection, penetrating atherosclerotic ulcer, and acute intramural hematoma. An understanding of the pathogenesis and distinguishing imaging features of acute aortic syndromes and aortic rupture and some less common manifestations is helpful when interpreting imaging examinations. Related entities, such as ulcerated plaque, ulcerlike projections, and intramural blood pools, and mimics, such as vasculitis and aortic thrombus, are important to recognize; knowledge of these is important to avoid interpretive pitfalls. In addition, an awareness of postsurgical aortic changes can be useful when interpreting CTA examinations when patient history is incomplete. The authors review technical considerations when performing CTA, discuss acute aortic syndromes, and highlight diagnostic challenges encountered when interpreting aortic CTA examinations. ©RSNA, 2021.

QUANTITATIVE ANALYSIS OF LONGITUDINAL CHANGES IN MULTIMODAL IMAGING OF LATE-ONSET RETINAL DEGENERATION.

PURPOSE: To quantitatively analyze clinically relevant features on longitudinal multimodal imaging of late-onset retinal degeneration to characterize disease progression. METHODS: Fundus autofluorescence (FAF), infrared reflectance, and optical coherence tomography imaging of 4 patients with late-onset retinal degeneration were acquired over 3 to 15 years (20 visits total). Corresponding regions of interest were analyzed on FAF (reticular pseudodrusen [RPD], "speckled FAF," and chorioretinal atrophy) and infrared reflectance (hyporeflective RPD and target RPD) using quantitative measurements, including contour area, distance to fovea, contour overlap, retinal thickness, and texture features. RESULTS: Cross-sectional analysis revealed a moderate correlation (RPD FAF ∩ RPD infrared reflectance = 63%) between contour area across modalities. Quantification of retinal thickness and texture analysis of areas contoured on FAF objectively differentiated the contour types. A longitudinal analysis of aligned images demonstrates that the contoured region of atrophy both encroaches toward the fovea and grows monotonically with a rate of 0.531 mm/year to 1.969 mm/year (square root of area, n = 5 eyes). A retrospective analysis of precursor lesions of atrophy reveals quantifiable progression from RPD to speckled FAF to atrophy. CONCLUSION: Image analysis of time points before the development of atrophy reveals consistent patterns over time and space in late-onset retinal degeneration that may provide useful outcomes for this and other degenerative retinal diseases.

MASSIVE ADVANCING NONEXUDATIVE TYPE 1 CHOROIDAL NEOVASCULARIZATION IN CTRP5 LATE-ONSET RETINAL DEGENERATION: Longitudinal Findings on Multimodal Imaging and Implications for Age-Related Macular Degeneration.

PURPOSE: To describe longitudinal multimodal imaging findings of nonexudative choroidal neovascularization in CTRP5 late-onset retinal degeneration. METHODS: Four patients with CTRP5-positive late-onset retinal degeneration underwent repeated ophthalmoscopic examination and multimodal imaging. All four patients (two siblings and their cousins, from a pedigree described previously) had the heterozygous S163R mutation. RESULTS: All four patients demonstrated large subretinal lesions in the mid-peripheral retina of both eyes. The lesions were characterized by confluent hypercyanescence with hypocyanescent borders on indocyanine green angiography, faintly visible branching vascular networks with absent/minimal leakage on fluorescein angiography, Type 1 neovascularization on optical coherence tomography angiography, and absent retinal fluid, consistent with nonexudative choroidal neovascularization. The neovascular membranes enlarged substantially over time and the birth of new membranes was observed, but all lesions remained nonexudative/minimally exudative. Without treatment, all involved retinal areas remained free of atrophy and subretinal fibrosis. CONCLUSION: We report the existence of massive advancing nonexudative Type 1 choroidal neovascularization in CTRP5 late-onset retinal degeneration. These findings have implications for age-related macular degeneration. They provide a monogenic model system for studying the mechanisms underlying the distinct events of choroidal neovascularization development, enlargement, progression to exudation, and atrophy in age-related macular degeneration. They suggest that choroidal hypoperfusion precedes neovascularization and that nonexudative neovascularization may protect against atrophy.

Association of Maternal Comorbidity With Severe Maternal Morbidity: A Cohort Study of California Mothers Delivering Between 1997 and 2014.

BACKGROUND: Rates of maternal mortality and severe maternal morbidity (SMM) are higher in the United States than in other high-resource countries and are increasing further. OBJECTIVE: To examine the association of maternal comorbid conditions, age, body mass index, and previous cesarean birth with occurrence of SMM. DESIGN: Population-based cohort study using linked delivery hospitalization discharge data and vital records. SETTING: California, 1997 to 2014. PATIENTS: All 9 179 472 mothers delivering in California during 1997 to 2014. MEASUREMENTS: SMM rate, total and without transfusion-only cases; 2019 maternal comorbidity index. RESULTS: Total SMM increased by 160% during this time, and SMM excluding transfusion-only cases increased by 53%. Medical comorbid conditions were associated with an increasing portion of SMM occurrences. Medical comorbid conditions increased over the study period by 111%, and obstetric comorbid conditions increased by 30% to 40%. Identified medical comorbid conditions had high relative risks ranging from 1.3 to 14.3 for total SMM and even higher relative risks for nontransfusion SMM (to 32.4). The obstetric comorbidity index that is most often used may be undervaluing the degree of association with SMM. LIMITATIONS: Hospital discharge diagnosis files and birth certificate records can have misclassifications and may not include all relevant clinical data or social determinants. The period for analysis ended in 2014 to avoid the transition to the International Classification of Diseases, 10th Revision, Clinical Modification, and therefore missed more recent years. CONCLUSION: Obstetric and, particularly, medical comorbid conditions are increasing among women who develop SMM. The maternal comorbidity index is a promising tool for patient risk assessment and case-mix adjustment, but refinement of factor weights may be indicated. PRIMARY FUNDING SOURCE: National Institutes of Health.