Maternal mortality in the United States: are the high and rising rates due to changes in obstetrical factors, maternal medical conditions, or maternal mortality surveillance?

BACKGROUND: National Vital Statistics System reports show that maternal mortality rates in the United States have nearly doubled, from 17.4 in 2018 to 32.9 per 100,000 live births in 2021. However, these high and rising rates could reflect issues unrelated to obstetrical factors, such as changes in maternal medical conditions or maternal mortality surveillance (eg, due to introduction of the pregnancy checkbox). OBJECTIVE: This study aimed to assess if the high and rising rates of maternal mortality in the United States reflect changes in obstetrical factors, maternal medical conditions, or maternal mortality surveillance. STUDY DESIGN: The study was based on all deaths in the United States from 1999 to 2021. Maternal deaths were identified using the following 2 approaches: (1) per National Vital Statistics System methodology, as deaths in pregnancy or in the postpartum period, including deaths identified solely because of a positive pregnancy checkbox, and (2) under an alternative formulation, as deaths in pregnancy or in the postpartum period, with at least 1 mention of pregnancy among the multiple causes of death on the death certificate. The frequencies of major cause-of-death categories among deaths of female patients aged 15 to 44 years, maternal deaths, deaths due to obstetrical causes (ie, direct obstetrical deaths), and deaths due to maternal medical conditions aggravated by pregnancy or its management (ie, indirect obstetrical deaths) were quantified. RESULTS: Maternal deaths, per National Vital Statistics System methodology, increased by 144% (95% confidence interval, 130-159) from 9.65 in 1999-2002 (n=1550) to 23.6 per 100,000 live births in 2018-2021 (n=3489), with increases occurring among all race and ethnicity groups. Direct obstetrical deaths increased from 8.41 in 1999-2002 to 14.1 per 100,000 live births in 2018-2021, whereas indirect obstetrical deaths increased from 1.24 to 9.41 per 100,000 live births: 38% of direct obstetrical deaths and 87% of indirect obstetrical deaths in 2018-2021 were identified because of a positive pregnancy checkbox. The pregnancy checkbox was associated with increases in less specific and incidental causes of death. For example, maternal deaths with malignant neoplasms listed as a multiple cause of death increased 46-fold from 0.03 in 1999-2002 to 1.42 per 100,000 live births in 2018-2021. Under the alternative formulation, the maternal mortality rate was 10.2 in 1999-2002 and 10.4 per 100,000 live births in 2018-2021; deaths from direct obstetrical causes decreased from 7.05 to 5.82 per 100,000 live births. Deaths due to preeclampsia, eclampsia, postpartum hemorrhage, puerperal sepsis, venous complications, and embolism decreased, whereas deaths due to adherent placenta, renal and unspecified causes, cardiomyopathy, and preexisting hypertension increased. Maternal mortality increased among non-Hispanic White women and decreased among non-Hispanic Black and Hispanic women. However, rates were disproportionately higher among non-Hispanic Black women, with large disparities evident in several causes of death (eg, cardiomyopathy). CONCLUSION: The high and rising rates of maternal mortality in the United States are a consequence of changes in maternal mortality surveillance, with reliance on the pregnancy checkbox leading to an increase in misclassified maternal deaths. Identifying maternal deaths by requiring mention of pregnancy among the multiple causes of death shows lower, stable maternal mortality rates and declines in maternal deaths from direct obstetrical causes.

Pregnancy-associated mortality due to cardiovascular disease: Impact of hypertensive disorders of pregnancy.

BACKGROUND: Reported rates of maternal mortality in the United States have been staggeringly high and increasing, and cardiovascular disease (CVD) is a chief contributor to such deaths. However, the impact of hypertensive disorders of pregnancy (HDP) on the short-term risk of cardiovascular death is not well understood. OBJECTIVES: To evaluate the association between HDP (chronic hypertension, gestational hypertension, preeclampsia, eclampsia, and superimposed preeclampsia) and pregnancy-associated mortality rates (PMR) from all causes, CVD-related causes both at delivery and within 1 year following delivery. METHODS: We used the Nationwide Readmissions Database (2010-2018) to examine PMRs for females 15-54 years old. International Classification of Disease 9 and 10 diagnosis codes were used to identify pregnancy-associated deaths due to HDP and CVD. Discrete-time Cox proportional hazards regression models were used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for mortality at delivery (0 days) and at <30, <60, <90, <180, and <365 days after delivery in relation to HDP. RESULTS: Of 33,417,736 hospital deliveries, the rate of HDP was 11.0% (n = 3,688,967), and the PMR from CVD was 6.4 per 100,000 delivery hospitalisations (n = 2141). Compared with normotensive patients, HRs for CVD-related PMRs increased with HDP severity, reaching over 58-fold for eclampsia patients. HRs were higher for stroke-related (1.2 to 170.9) than heart disease (HD)-related (0.99 to 39.8) mortality across all HDPs. Except for gestational hypertension, the increased risks of CVD mortality were evident at delivery and persisted 1 year postpartum for all HDPs. CONCLUSIONS: HDPs are strong risk factors for pregnancy-associated mortality due to CVD at delivery and within 1 year postpartum; the risks are stronger for stroke than HD-related PMR. While absolute PMRs are low, this study supports the importance of extending postpartum care beyond the traditional 42-day postpartum visit for people whose pregnancies are complicated by hypertension.

Uptake rate of carrier screening among consanguineous couples.

OBJECTIVE: To quantify the uptake rates of Carrier Screening (CS) in consanguineous couples and compare this rate to that of non-consanguineous couples. METHODS: We performed a matched case control study of 82 consanguineous couples seen at Rutgers-Robert Wood Johnson Medical school who were offered carrier screening between January 1, 2012 and October 10, 2022. We then matched each consanguineous female patient to a non-consanguineous female control patient who was also offered CS at the time of their genetic counseling appointment. A 2 × 2 contingency table analysis was used to compare rates of acceptance and declination between the consanguineous and non-consanguineous groups. RESULTS: The overall acceptance rate among consanguineous couples was 82.9%, whereas the overall acceptance rate among non-consanguineous couples was 56.1%. After statistical analysis, consanguineous couples were significantly more likely to accept CS as compared to non-consanguineous couples (OR = 3.801, 95% CI; p < 0.0001). We also report the carrier couple rates and individual carrier statistics between these two groups. CONCLUSION: This study supports the idea that consanguineous couples are more likely to pursue CS and have a higher carrier couple yield.

Effect of the COVID-19 Pandemic on Stillbirths in Canada and the United States.

OBJECTIVE: There is uncertainty regarding the effect of the COVID-19 pandemic on population rates of stillbirth. We quantified pandemic-associated changes in stillbirth rates in Canada and the United States. METHODS: We carried out a retrospective study that included all live births and stillbirths in Canada and the United States from 2015 to 2020. The primary analysis was based on all stillbirths and live births at ≥20 weeks gestation. Stillbirth rates were analyzed by month, with March 2020 considered to be the month of pandemic onset. Interrupted time series analyses were used to determine pandemic effects. RESULTS: The study population included 18 475 stillbirths and 2 244 240 live births in Canada and 134 883 stillbirths and 22 963 356 live births in the United States (8.2 and 5.8 stillbirths per 1000 total births, respectively). In Canada, pandemic onset was associated with an increase in stillbirths at ≥20 weeks gestation of 1.01 (95% confidence interval [CI] 0.56-1.46) per 1000 total births and an increase in stillbirths at ≥28 weeks gestation of 0.35 (95% CI 0.16-0.54) per 1000 total births. In the United States, pandemic onset was associated with an increase in stillbirths at ≥20 weeks gestation of 0.48 (95% CI 0.22-0.75) per 1000 total births and an increase in stillbirths at ≥28 weeks gestation of 0.22 (95% CI 0.12-0.32) per 1000 total births. The increase in stillbirths at pandemic onset returned to pre-pandemic levels in subsequent months. CONCLUSION: The COVID-19 pandemic's onset was associated with a transitory increase in stillbirth rates in Canada and the United States.

Epidemiologic trends and risk factors associated with the decline in mortality from coronary heart disease in the United States, 1990-2019.

BACKGROUND: Despite the decline in the rate of coronary heart disease (CHD) mortality, it is unknown how the 3 strong and modifiable risk factors - alcohol, smoking, and obesity -have impacted these trends. We examine changes in CHD mortality rates in the United States and estimate the preventable fraction of CHD deaths by eliminating CHD risk factors. METHODS: We performed a sequential time-series analysis to examine mortality trends among females and males aged 25 to 84 years in the United States, 1990-2019, with CHD recorded as the underlying cause of death. We also examined mortality rates from chronic ischemic heart disease (IHD), acute myocardial infarction (AMI), and atherosclerotic heart disease (AHD). All underlying causes of CHD deaths were classified based on the International Classification of Disease 9th and 10th revisions. We estimated the preventable fraction of CHD deaths attributable to alcohol, smoking, and high body-mass index (BMI) through the Global Burden of Disease. RESULTS: Among females (3,452,043 CHD deaths; mean [standard deviation, SD] age 49.3 [15.7] years), the age-standardized CHD mortality rate declined from 210.5 in 1990 to 66.8 per 100,000 in 2019 (annual change -4.04%, 95% CI -4.05, -4.03; incidence rate ratio [IRR] 0.32, 95% CI, 0.41, 0.43). Among males (5,572,629 CHD deaths; mean [SD] age 47.9 [15.1] years), the age-standardized CHD mortality rate declined from 442.4 to 156.7 per 100,000 (annual change -3.74%, 95% CI, -3.75, -3.74; IRR 0.36, 95% CI, 0.35, 0.37). A slowing of the decline in CHD mortality rates among younger cohorts was evident. Correction for unmeasured confounders through a quantitative bias analysis slightly attenuated the decline. Half of all CHD deaths could have been prevented with the elimination of smoking, alcohol, and obesity, including 1,726,022 female and 2,897,767 male CHD deaths between 1990 and 2019. CONCLUSIONS: The decline in CHD mortality is slowing among younger cohorts. The complex dynamics of risk factors appear to shape mortality rates, underscoring the importance of targeted strategies to reduce modifiable risk factors that contribute to CHD mortality.

Placental abruption at near-term and term gestations: pathophysiology, epidemiology, diagnosis, and management.

Placental abruption is the premature separation of the placenta from its uterine attachment before the delivery of a fetus. The clinical manifestations of abruption typically include vaginal bleeding and abdominal pain with a wide variety of abnormal fetal heart rate patterns. Clinical challenges arise when pregnant people with this condition present with profound vaginal bleeding, necessitating urgent delivery, especially when there is a concern for maternal and fetal compromise and coagulopathy. Abruption occurs in 0.6% to 1.2% of all pregnancies, with nearly half of abruption occurring at term gestations. An exposition of abruption at near-term (defined as the late preterm period from 34 0/7 to 36 6/7 weeks of gestation) and term (defined as ≥37 weeks of gestation) provides unique insights into its direct effects, as risks associated with preterm birth do not impact outcomes. Here, we explore the pathophysiology, epidemiology, and diagnosis of abruption. We discuss the interaction of chronic processes (decidual and uteroplacental vasculopathy) and acute processes (shearing forces applied to the abdomen) that underlie the pathophysiology. Risk factors for abruption and strengths of association are summarized. Sonographic findings of abruption and fetal heart rate tracings are presented. In addition, we propose a management algorithm for acute abruption that incorporates blood loss, vital signs, and urine output, among other factors. Lastly, we discuss blood component therapy, viscoelastic point-of-care testing, disseminated intravascular coagulopathy, and management of abruption complicated by fetal death. The review seeks to provide comprehensive, clinically focused guidance during a gestational age range when neonatal outcomes can often be favorable if rapid and evidence-based care is optimized.

Clinical risk factors of adverse outcomes among women with COVID-19 in the pregnancy and postpartum period: a sequential, prospective meta-analysis.

OBJECTIVE: This sequential, prospective meta-analysis sought to identify risk factors among pregnant and postpartum women with COVID-19 for adverse outcomes related to disease severity, maternal morbidities, neonatal mortality and morbidity, and adverse birth outcomes. DATA SOURCES: We prospectively invited study investigators to join the sequential, prospective meta-analysis via professional research networks beginning in March 2020. STUDY ELIGIBILITY CRITERIA: Eligible studies included those recruiting at least 25 consecutive cases of COVID-19 in pregnancy within a defined catchment area. METHODS: We included individual patient data from 21 participating studies. Data quality was assessed, and harmonized variables for risk factors and outcomes were constructed. Duplicate cases were removed. Pooled estimates for the absolute and relative risk of adverse outcomes comparing those with and without each risk factor were generated using a 2-stage meta-analysis. RESULTS: We collected data from 33 countries and territories, including 21,977 cases of SARS-CoV-2 infection in pregnancy or postpartum. We found that women with comorbidities (preexisting diabetes mellitus, hypertension, cardiovascular disease) vs those without were at higher risk for COVID-19 severity and adverse pregnancy outcomes (fetal death, preterm birth, low birthweight). Participants with COVID-19 and HIV were 1.74 times (95% confidence interval, 1.12-2.71) more likely to be admitted to the intensive care unit. Pregnant women who were underweight before pregnancy were at higher risk of intensive care unit admission (relative risk, 5.53; 95% confidence interval, 2.27-13.44), ventilation (relative risk, 9.36; 95% confidence interval, 3.87-22.63), and pregnancy-related death (relative risk, 14.10; 95% confidence interval, 2.83-70.36). Prepregnancy obesity was also a risk factor for severe COVID-19 outcomes including intensive care unit admission (relative risk, 1.81; 95% confidence interval, 1.26-2.60), ventilation (relative risk, 2.05; 95% confidence interval, 1.20-3.51), any critical care (relative risk, 1.89; 95% confidence interval, 1.28-2.77), and pneumonia (relative risk, 1.66; 95% confidence interval, 1.18-2.33). Anemic pregnant women with COVID-19 also had increased risk of intensive care unit admission (relative risk, 1.63; 95% confidence interval, 1.25-2.11) and death (relative risk, 2.36; 95% confidence interval, 1.15-4.81). CONCLUSION: We found that pregnant women with comorbidities including diabetes mellitus, hypertension, and cardiovascular disease were at increased risk for severe COVID-19-related outcomes, maternal morbidities, and adverse birth outcomes. We also identified several less commonly known risk factors, including HIV infection, prepregnancy underweight, and anemia. Although pregnant women are already considered a high-risk population, special priority for prevention and treatment should be given to pregnant women with these additional risk factors.

Early coronavirus disease 2019 restrictive measures and changes in maternal characteristics, use of assisted reproductive technology, and stillbirth.

BACKGROUND: The initial COVID-19 pandemic response-related effects on conceptions following the use of assisted reproductive technologies (ART), and on changes in the maternal characteristics of women who conceived during the early vs. pre-pandemic period, have been understudied. OBJECTIVES: To examine the effects of ART clinic closures in the United States (US) in March 2020 on the frequency of ART-conceived live births, multiple births and stillbirths; and to describe changes in the characteristics of women who conceived in the early pandemic period. METHODS: Population-based cohort study including all births in the US from January 2015 to December 2020 (22,907,688 live births; 134,537 stillbirths). Interrupted time series (ITS) methodology was used to estimate rate ratios (RR) of expected versus observed rates in December 2020 (i.e., among births conceived mainly in March 2020). Demographic and clinical characteristics were compared between mothers who conceived in March 2020 versus March 2015-2019. RESULTS: Overall, 1.1% of live births and 1.7% of stillbirths were conceived by ART. ART-conceived live births decreased by 57.0% in December 2020 (observed vs. expected RR 0.43, 95% confidence interval [CI] 0.40, 0.45), and these declines occurred in all subgroups of women. Multiple births also declined in December 2020. Stillbirth rates increased in December 2020 in ART-conceived births (RR 2.55, 95% CI 1.63, 3.92) but remained unchanged in the non-ART group. Maternal characteristics of women who conceived in the early pandemic versus pre-pandemic period differed and included an increased prevalence of pre-pregnancy obesity class 3 and chronic hypertension. CONCLUSIONS: The early pandemic closure of ART clinics resulted in a substantial decline in ART-conceived live births and multiple births in December 2020 and an increase in the proportion of stillbirths among ART-conceived births. Women who conceived in the early pandemic period also had an increased prevalence of obesity and chronic hypertension.

Rate of manifesting carriers and other unexpected findings on carrier screening.

OBJECTIVES: To ascertain the rate of unexpected findings on carrier screening (CS) and assess whether implications are disclosed to patients. METHODS: We performed a retrospective observational study of subjects who had CS after pre-test counseling from a licensed genetic counselor at a large tertiary care center. We quantified the rate of unexpected finding on CS, defined as manifesting carriers (MCs), genotypes predicting phenotype, and chromosome abnormalities. We determined how often patients were informed of implications. We performed subgroup analyses by type of unexpected finding and calculated odds ratios (OR) and 95% confidence intervals (CI) for carrier testing methodology (genotype) and number of genes tested. RESULTS: A total of 4685 patients had CS over the selected time frame. Of those patients, 412 patients (8.8%) had one unexpected finding and 29 patients (0.6%) had two or more findings. In total, 466 unexpected findings were identified, including 437 MC conditions, 23 genotypes predicting phenotype, and 6 chromosome abnormalities. Patients were informed of the implications for MCs, genotypes predicting phenotype, and chromosome abnormalities in 27.6%, 91.3%, and 100% of cases, respectively. More unexpected findings were detected with sequencing compared to genotyping (OR 2.21 and 95% CI 1.76-2.76) and with ≥200 gene panels compared to <200 gene panels (OR 1.79 and 95% CI 1.47-2.17). CONCLUSION: This study highlights that nondisclosure of unexpected findings on CS is common and underscores the need for further research to improve post-test counseling and follow-up.

Fifty years of the Journal of Perinatal Medicine: an altmetric and bibliometric study.

OBJECTIVES: To apply scientometric methodology to characterize influential articles in the Journal of Perinatal Medicine (JPM). METHODS: We performed a cross-sectional study of all JPM articles indexed in Clarivate Web of Science (WOS), NIH Open Citation Collection, and Altmetric Explorer databases (1973-2022). We identified articles cited ≥100 times in WOS and articles with highest Relative Citation Ratios (RCR, a metric of influence based on citations) and highest Altmetric Attention Scores (AAS, a metric of engagement with social media and public platforms). We performed descriptive analysis to characterize influential articles based on citation rates vs. highest AAS, and quantile regression with bootstrapping to estimate the median differences (95% confidence intervals). RESULTS: We identified 4095 JPM articles that were indexed in the WOS, of which 3,959 (96.7%) had RCRs and 939 (22.9%) had AASs. The study cohort included 34 articles cited ≥100 times and the 34 top-RCR and 34 top-AAS articles, representing 83 unique articles. These influential articles had median 67 citations (IQR 17-114), median RCR 3.4 (IQR 1.7-5.0), and median AAS 14 (IQR 3-28). The majority were observational studies and reviews. Compared to top-AAS articles, top-cited articles had higher median citations (117 [IQR 111-147] vs. 13 [IQR 5-62]; median difference 104.0, 95% CI 86.6-121.4) and citations per year (7.3 [IQR 4.9-10.6] vs. 2.3 [0.7-4.6]; median difference 5.5 [95% CI 3.1-7.9]). Results were similar for top-RCR vs. top-AAS articles. CONCLUSIONS: We identified influential articles during 50 years of JPM, providing insight into the impact of the journal and providing a template for future studies of academic journals.

Invited Commentary: Intermittent Opioid Use and Ischemic Placental Disease-Clarifying Associations With Adverse Pregnancy Outcomes.

Discomfort and, to a lesser extent, pain are common complaints during pregnancy, and some patients may turn to opioids for pain relief. Esposito et al. (Am J Epidemiol. 2022;191(5):759-768) report associations between intermittent exposure to opioids during pregnancy and the risk of ischemic placental disease-a syndrome that includes preeclampsia, placental abruption, births that are small for gestational age, and preterm delivery. They found that early opioid exposure in pregnancy was associated with a modestly increased risk for abruption, births that are small for gestational age, and preterm delivery, and both early and late exposures were associated with the greatest risk for these outcomes. Surprisingly, preeclampsia was not associated with opioid use. Through quantitative bias analysis, the authors cleverly tackle a number of biases to assess their roles in explaining the associations, including unmeasured confounding, outcome misclassification, and residual confounding; none exerted strong influences on the associations. Although the findings appear fairly robust on the surface, the lack of association between intermittent opioid use and preeclampsia, and important differences in characteristics of patients in the opioid-exposed group compared with the unexposed group, suggest that further study is needed to clarify the relationship between intermittent opioid use, lifestyle factors, and ischemic placental disease risk.

A principled approach to mediation analysis in perinatal epidemiology.

For many research questions in perinatal epidemiology, gestational age is a mediator that features the causal pathway between exposure and outcome. A mediator is an intermediate variable between an exposure and outcome, which is influenced by the exposure on the causal pathway to the outcome. Therefore, conventional analyses that adjust, stratify, or match for gestational age or its proxy (eg, preterm vs term deliveries) are problematic. This practice, which is entrenched in perinatal research, induces an overadjustment bias. Depending on the causal question, it may be inappropriate to adjust (or condition) for a mediator, such as gestational age, by either design or statistical analysis, but its effect can be quantified through causal mediation analysis. In an exposition of such methods, we demonstrated the relationship between the exposure and outcome and provided a formal analytical framework to quantify the extent to which a causal effect is influenced by a mediator. We reviewed concepts of confounding and causal inference, introduced the concept of a mediator and illustrated the perils of adjusting for a mediator in an exposure-outcome paradigm for a given causal question, adopted causal methods that call for an evaluation of a mediator in a causal exposure effect on the outcome, and discussed unmeasured confounding assumptions in mediation analysis. Furthermore, we reviewed other developments in the causal mediation analysis literature, including decomposition of a total effect when the mediator interacts with the exposure (4-way decomposition), methods for multiple mediators, mediation methods for case-control studies, mediation methods for time-to-event outcomes, sample size and power analysis for mediation analysis, and available software to apply these methods. To illustrate these methods, we provided a clinical example to estimate the risk of perinatal mortality (outcome) concerning placental abruption (exposure) and to determine the extent to which preterm delivery (mediator; a proxy for gestational age) plays a role in this causal effect. We hoped that the adoption of mediation methods described in this review will move research in perinatal epidemiology away from biased adjustments of mediators toward a more nuanced quantification of effects that pose unique challenges and provide unique insights in our field.

Society for Maternal-Fetal Medicine Special Statement: Commitment to excellence in obstetrical care, research, and education for people with diverse sexual and gender identities.

The Society for Maternal-Fetal Medicine seeks to ensure excellence in obstetrical outcomes for all people who desire or experience pregnancy, including people with diverse sexual and gender identities. The Society commits to the use of practices in clinical and research settings that affirm the sexual and gender identities of all people, encourages the development of undergraduate and graduate medical education curricula and training programs that address diverse pathways to pregnancy and support clinicians with diverse sexual and gender identities, and promotes the use of inclusive language that is accurate and, when possible, specific.

Altmetric and bibliometric analysis of obstetrics and gynecology research: influence of public engagement on citation potential.

BACKGROUND: Whether research engagement on social media and other public platforms results in increased citations in obstetrics and gynecology remains uncertain. The Altmetric Attention Score is a metric of research influence based on mentions on social media and public platforms, such as newsfeeds and Wikipedia. The correlation between Altmetric Attention Scores, absolute citation rates, and the Relative Citation Ratio (a novel metric of research engagement also based on citation rates) in obstetrics and gynecology research is uncertain. OBJECTIVE: To evaluate the correlation between Altmetric Attention Score, absolute citation rate, and Relative Citation Ratio for articles published in obstetrics and gynecology journals from 2004 to 2019. Our second objective was to identify, characterize, and compare the 100 articles with highest Altmetric Attention Scores, the 100 most-cited articles, and the 100 articles with highest Relative Citation Ratios. STUDY DESIGN: We performed a cross-sectional altmetric and bibliometric study of all obstetrics and gynecology articles indexed in the National Institutes of Health Open Citation Collection from 2004 to 2019. Articles were included if they were published in obstetrics and gynecology journals according to InCites Journal Citation Reports indexing. Citation data, including citation numbers and Relative Citation Ratios, were downloaded on March 20, 2021 and merged with altmetric data from the Altmetric Explorer on the basis of each article's unique PubMed identification number. We assessed correlation between Altmetric Attention Scores and number of citations and Altmetric Attention Scores and Relative Citation Ratios by calculating the Pearson correlation coefficient. The 100 articles with highest Altmetric Attention Scores, the 100 most-cited articles, and the 100 articles with highest Relative Citation Ratios were characterized and compared using means (standard deviations) and mean differences (95% confidence intervals). RESULTS: There were 156,592 articles published in 82 obstetrics and gynecology journals and indexed in the National Institutes of Health Open Citation Collection between 2004 and 2019. The correlation coefficient was 0.18 (95% confidence interval, 0.17-0.19) for Altmetric Attention Scores vs number of citations and 0.10 (95% confidence interval, 0.09-0.11) for Altmetric Attention Scores vs Relative Citation Ratios. There was no overlap among the 100 articles on the highest Altmetric Attention Score list and the 100 most-cited list, and there was minimal overlap among the 100 articles on the highest Altmetric Attention Score list and the 100 highest Relative Citation Ratio list (98 unique articles on each list). Articles with highest Altmetric Attention Scores generated substantially more engagement on social media and other public platforms than most-cited articles (mean Altmetric Attention Score, 763.1 [standard deviation, 520.8] vs 49.9 [standard deviation, 81.6]; mean difference, -713.2 [95% confidence interval, -819.9 to -606.6]) and highest Relative Citation Ratio articles (mean, 116.2 [standard deviation, 415.9]; mean difference, -661.5 [95% confidence interval, -746.2 to -576.9]). In contrast, the articles with highest Altmetric Attention Scores generated far fewer citations than most-cited articles (mean, 39.7 [standard deviation, 47.6] vs 541.8 [standard deviation, 312.8]; mean difference, 502.0 [95% confidence interval, 439.0-565.0]) and highest Relative Citation Ratio articles (mean, 458.9 [standard deviation, 363.5]; mean difference, 427.7 [95% confidence interval, 353.8-501.6]). Nearly half of articles with highest Altmetric Attention Scores were basic/translational studies, often about menopause and environmental factors impacting fertility, whereas most-cited articles and articles with highest Relative Citation Ratios were more likely to be reviews and consensus statements, respectively, often about placentation and polycystic ovary syndrome, respectively. Articles with highest Altmetric Attention Scores were more likely to be published as open-access. CONCLUSION: There seems to be weak short-term correlation between Altmetric Attention Scores and citation rates. Further study is warranted to ascertain whether there may be long-term correlation between alternative metrics and citation rates in obstetrics and gynecology.

Epidemiology of coronavirus disease 2019 in pregnancy: risk factors and associations with adverse maternal and neonatal outcomes.

BACKGROUND: Coronavirus disease 2019 may be associated with adverse maternal and neonatal outcomes in pregnancy, but there are few controlled data to quantify the magnitude of these risks or to characterize the epidemiology and risk factors. OBJECTIVE: This study aimed to quantify the associations of coronavirus disease 2019 with adverse maternal and neonatal outcomes in pregnancy and to characterize the epidemiology and risk factors. STUDY DESIGN: We performed a matched case-control study of pregnant patients with confirmed coronavirus disease 2019 cases who delivered between 16 and 41 weeks' gestation from March 11 to June 11, 2020. Uninfected pregnant women (controls) were matched to coronavirus disease 2019 cases on a 2:1 ratio based on delivery date. Maternal demographic characteristics, coronavirus disease 2019 symptoms, laboratory evaluations, obstetrical and neonatal outcomes, and clinical management were chart abstracted. The primary outcomes included (1) a composite of adverse maternal outcome, defined as preeclampsia, venous thromboembolism, antepartum admission, maternal intensive care unit admission, need for mechanical ventilation, supplemental oxygen, or maternal death, and (2) a composite of adverse neonatal outcome, defined as respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, 5-minute Apgar score of <5, persistent category 2 fetal heart rate tracing despite intrauterine resuscitation, or neonatal death. To quantify the associations between exposure to mild and severe or critical coronavirus disease 2019 and adverse maternal and neonatal outcomes, unadjusted and adjusted analyses were performed using conditional logistic regression (to account for matching), with matched-pair odds ratio and 95% confidence interval based on 1000 bias-corrected bootstrap resampling as the effect measure. Associations were adjusted for potential confounders. RESULTS: A total of 61 confirmed coronavirus disease 2019 cases were enrolled during the study period (mild disease, n=54 [88.5%]; severe disease, n=6 [9.8%]; critical disease, n=1 [1.6%]). The odds of adverse composite maternal outcome were 3.4 times higher among cases than controls (18.0% vs 8.2%; adjusted odds ratio, 3.4; 95% confidence interval, 1.2-13.4). The odds of adverse composite neonatal outcome were 1.7 times higher in the case group than to the control group (18.0% vs 13.9%; adjusted odds ratio, 1.7; 95% confidence interval, 0.8-4.8). Stratified analyses by disease severity indicated that the morbidity associated with coronavirus disease 2019 in pregnancy was largely driven by the severe or critical disease phenotype. Major risk factors for associated morbidity were black and Hispanic race, advanced maternal age, medical comorbidities, and antepartum admissions related to coronavirus disease 2019. CONCLUSION: Coronavirus disease 2019 during pregnancy is associated with an increased risk of adverse maternal and neonatal outcomes, an association that is primarily driven by morbidity associated with severe or critical coronavirus disease 2019. Black and Hispanic race, obesity, advanced maternal age, medical comorbidities, and antepartum admissions related to coronavirus disease 2019 are risk factors for associated morbidity.

Lymphoma Occurring During Pregnancy: Current Diagnostic and Therapeutic Approaches.

PURPOSE OF REVIEW: Pregnancy-associated lymphoma (PAL) is an uncommon entity that lacks detailed prospective data. It poses significant management challenges that incorporate maternal and fetal risks associated with treatment or delayed intervention. Herein, we review the current literature for the diagnosis, management, and supportive care strategies for PAL. RECENT FINDINGS: Establishment of a multidisciplinary team, including hematology-oncology, maternal-fetal medicine, and neonatology, is critical in the management of PAL. For staging, ultrasound and MRI are preferred modalities with use of computerized tomography in select situations. Data for the safety and effectiveness of therapy for PAL is largely based on retrospective studies. The timing of lymphoma-directed antenatal systemic therapy depends on the trimester, gestational age, lymphoma subtype and aggressiveness, and patient wishes. Therapy in the first trimester is usually not advocated, while treatment in the second and third trimesters appears to result in similar outcomes for PAL compared with non-pregnant patients with lymphoma. An overarching goal in most PAL cases should be to plan for delivery at term (i.e., gestational age > 37 weeks). For supportive care, most antiemetics, including agents such as neurokinin-1 receptor antagonists, have been used safely during pregnancy. For prevention or treatment of infections, particular antibiotics (i.e., macrolides, cephalosporins, penicillins, metronidazole), antivirals (i.e., acyclovir, valacyclovir, famciclovir), and antifungals (amphotericin B) have demonstrated safety and with use of growth factors reserved for treatment of neutropenia (vs. primary prophylaxis). Therapy for PAL should be individualized with goals of care that balance maternal and fetal well-being, which should include a multidisciplinary care team and overall intent for term delivery in most cases.

A Bibliometric Analysis of Citation Classics in the Journal of Ultrasound in Medicine.

OBJECTIVES: A bibliometric analysis of articles in the Journal of Ultrasound in Medicine (JUM) identified the journals' most impactful articles. METHODS: A bibliometric analysis of citation classics that were published in the JUM from its inception in 1982 to 2019 was performed. All citation classics, defined as articles cited 100 or more times, were evaluated for the number of citations, citations per year, publication year, subspecialty, design, and country of origin. Characteristics were compared before and after 1998 by the Mann-Whitney test for unpaired data and 2-sample z tests of sample proportions. The Kruskal-Wallis test for nonparametric continuous data was used to compare the median number of citations per year by decade of publication. RESULTS: A total of 7868 articles were published in the JUM between 1982 and 2019; 54 (0.7%) were citation classics. The median citation classics year of publication was 1998 (interquartile range [IQR], 1991-2003). Most citation classics originated from the United States (36 of 54 [66.7%]), were observational (47 of 54 [87%]), and were related to obstetric and gynecologic topics (16 of 54 [29.6%]). Citation classics after 1998 received significantly more citations per year (9.3 versus 4.7; P < .001), with no other differences noted. The median number of citations per year increased for each decade, with medians of 4 citations (IQR, 3.6-4.7) in 1982 to 1991 and 11.2 citations (IQR, 9-13.9) in 2002 to 2012 (P < .001). CONCLUSIONS: This list provides insight into the most influential articles that were published in the JUM. Most citation classics were observational, were from the United States, and covered obstetric and gynecologic topics. Citation classics received more citations per year after 1998.

Top-cited articles in the Journal: a bibliometric analysis.

BACKGROUND: The Journal has had a profound influence in nearly 150 years of publishing. A bibliometric analysis, which uses citation analyses to evaluate the impact of articles, can be used to identify the most impactful papers in the Journal's history. OBJECTIVE: The objective was to identify and characterize the top-cited articles published in the Journal since 1920. STUDY DESIGN: We used the Web of Science and Scopus databases to identify the most frequently cited articles of the Journal from 1920 through 2018. The top 100 articles from each database were included in our analysis. Articles were evaluated for several characteristics including year of publication, article type, topic, open access, and country of origin. Using the Scopus data, we performed an unadjusted categorical analysis to characterize the articles and a 2 time point analysis to compare articles before and after 1995, the median year of publication from each database list. RESULTS: The top 100 articles from each database were included in the analysis. This included 120 total articles: 80 articles listed in both and 20 unique in each database. More than half (52%) were observational studies, 9% were RCTs, and 75% were from US authors. When the post-1995 studies were compared with the articles published before 1995, articles were more frequently cited (median 27 vs 13 citations per year, P < .001), more likely to be randomized (14.0% vs 4.8%, P = .009), and more likely to originate from international authors (33.3% vs 17.5%, P = .045). CONCLUSION: Slightly more than half of the top-cited papers in the Journal since 1920 were observational studies and three quarters of all papers were from US authors. Compared with top-cited papers before 1995, the Journal's top-cited papers after 1995 were more likely to be randomized and to originate from international authors.