Peripartum cardiomyopathy unveiled: Etiology, diagnosis, and therapeutic insights.

Peripartum cardiomyopathy (PPCM) remains a significant challenge in maternal health, marked by its unpredictable onset and varied clinical outcomes. With rising incidence rates globally, understanding PPCM is vital for improving maternal care and prognosis. This review aims to consolidate current knowledge on PPCM, highlighting recent advancements in its diagnosis, management, and therapeutic approaches. This comprehensive review delves into the epidemiology of PPCM, underscoring its global impact and demographic variations. We explore the complex etiology of the condition, examining known risk factors and discussing the potential pathophysiological mechanisms, including oxidative stress and hormonal influences. The clinical presentation of PPCM, often similar yet distinct from other forms of cardiomyopathy, is analyzed to aid in differential diagnosis. Diagnostic challenges are addressed, emphasizing the role of advanced imaging and biomarkers. Current management strategies are reviewed, focusing on the absence of disease-specific treatments and the application of general heart failure protocols. The review also discusses the prognosis of PPCM, factors influencing recovery, and the implications for future pregnancies. Finally, we highlight emerging research directions and the urgent need for disease-specific therapies, aiming to provide a roadmap for future studies and improved patient care. This review serves as a crucial resource for clinicians and researchers, contributing to a deeper understanding and better management of PPCM.

A 20-year population study of peripartum cardiomyopathy.

BACKGROUND AND AIMS: The epidemiology of peripartum cardiomyopathy (PPCM) in Europe is poorly understood and data on long-term outcomes are lacking. A retrospective, observational, population-level study of validated cases of PPCM in Scotland from 1998 to 2017 was conducted. METHODS: Women hospitalized with presumed de novo left ventricular systolic dysfunction around the time of pregnancy and no clear alternative cause were included. Each case was matched to 10 controls. Incidence and risk factors were identified. Morbidity and mortality were examined in mothers and children. RESULTS: The incidence of PPCM was 1 in 4950 deliveries. Among 225 women with PPCM, obesity, gestational hypertensive disorders, and multi-gestation were found to be associated with having the condition. Over a median of 8.3 years (9.7 years for echocardiographic outcomes), 8% of women with PPCM died and 75% were rehospitalized for any cause at least once. Mortality and rehospitalization rates in women with PPCM were ∼12- and ∼3-times that of controls, respectively. The composite of all-cause death, mechanical circulatory support, or cardiac transplantation occurred in 14%. LV recovery occurred in 76% and, of those who recovered, 13% went on to have a decline in LV systolic function despite initial recovery. The mortality rate for children born to women with PPCM was ∼5-times that of children born to controls and they had an ∼3-times greater incidence of cardiovascular disease over a median of 8.8 years. CONCLUSIONS: PPCM affected 1 in 4950 women around the time of pregnancy. The condition is associated with considerable morbidity and mortality for the mother and child. There should be a low threshold for investigating at-risk women. Long term follow-up, despite apparent recovery, should be considered.

Proteomic Profiling in Patients With Peripartum Cardiomyopathy: A Biomarker Study of the ESC EORP PPCM Registry.

BACKGROUND: Peripartum cardiomyopathy (PPCM) remains an important cause of maternal morbidity and mortality globally. The pathophysiology remains incompletely understood, and the diagnosis is often missed or delayed. OBJECTIVES: This study explored the serum proteome profile of patients with newly diagnosed PPCM, as compared with matched healthy postpartum mothers, to unravel novel protein biomarkers that would further an understanding of the pathogenesis of PPCM and improve diagnostic precision. METHODS: Study investigators performed untargeted serum proteome profiling using data-independent acquisition-based label-free quantitative liquid chromatography-tandem mass spectrometry on 84 patients with PPCM, as compared with 29 postpartum healthy controls (HCs). Significant changes in protein intensities were determined with nonpaired Student's t-tests and were further classified by using the Boruta algorithm. The proteins' diagnostic performance was evaluated by area under the curve (AUC) and validated using the 10-fold cross-validation. RESULTS: Patients with PPCM presented with a mean left ventricular ejection fraction of 33.5% ± 9.3% vs 57.0% ± 8.8% in HCs (P < 0.001). Study investigators identified 15 differentially up-regulated and 14 down-regulated proteins in patients with PPCM compared with HCs. Seven of these proteins were recognized as significant by the Boruta algorithm. The combination of adiponectin, quiescin sulfhydryl oxidase 1, inter-α-trypsin inhibitor heavy chain, and N-terminal pro-B-type natriuretic peptide had the best diagnostic precision (AUC: 0.90; 95% CI: 0.84-0.96) to distinguish patients with PPCM from HCs. CONCLUSIONS: Salient biologic themes related to immune response proteins, inflammation, fibrosis, angiogenesis, apoptosis, and coagulation were predominant in patients with PPCM compared with HCs. These newly identified proteins warrant further evaluation to establish their role in the pathogenesis of PPCM and potential use as diagnostic markers.

Validation of Risk Stratification for Cardiac Events in Pregnant Women With Valvular Heart Disease.

BACKGROUND: Most risk stratification tools for pregnant patients with heart disease were developed in high-income countries and in populations with predominantly congenital heart disease, and therefore, may not be generalizable to those with valvular heart disease (VHD). OBJECTIVES: The purpose of this study was to validate and establish the clinical utility of 2 risk stratification tools-DEVI (VHD-specific tool) and CARPREG-II-for predicting adverse cardiac events in pregnant patients with VHD. METHODS: We conducted a cohort study involving consecutive pregnancies complicated with VHD admitted to a tertiary center in a middle-income setting from January 2019 to April 2022. Individual risk for adverse composite cardiac events was calculated using DEVI and CARPREG-II models. Performance was assessed through discrimination and calibration characteristics. Clinical utility was evaluated with Decision Curve Analysis. RESULTS: Of 577 eligible pregnancies, 69 (12.1%) experienced a component of the composite outcome. A majority (94.7%) had rheumatic etiology, with mitral regurgitation as the predominant lesion (48.2%). The area under the receiver-operating characteristic curve was 0.884 (95% CI: 0.844-0.923) for the DEVI and 0.808 (95% CI: 0.753-0.863) for the CARPREG-II models. Calibration plots suggested that DEVI score overestimates risk at higher probabilities, whereas CARPREG-II score overestimates risk at both extremes and underestimates risk at middle probabilities. Decision curve analysis demonstrated that both models were useful across predicted probability thresholds between 10% and 50%. CONCLUSIONS: In pregnant patients with VHD, DEVI and CARPREG-II scores showed good discriminative ability and clinical utility across a range of probabilities. The DEVI score showed better agreement between predicted probabilities and observed events.

Knowledge Levels and Predictors of Venous Thromboembolism among Pregnant Women in Nigeria: A Cross-Sectional Survey for the 'Move for Flow' Programme.

BACKGROUND: Pregnancy is a significant risk factor for Venous Thromboembolism (VTE) which results in high maternal and perinatal morbidity and mortality rates. Awareness creation is one of the preventable strategies of VTE. To this effect, we designed the 'Move for Flow' program aimed at maternal health education on VTE, its symptoms and preventive strategies. For the best implementation of this program, the current knowledge level of the relevant population is of great interest in guiding the program design and implementation. AIM: To assess the knowledge levels of VTE among Nigerian pregnant women. METHODOLOGY: In this cross-sectional survey, 1000 pregnant women residing in Enugu, Nigeria, completed a structured questionnaire which assessed their knowledge of VTE, its risk factors and prevention strategies. Quantitatively, their knowledge levels were categorized as no, poor, average and good knowledge. RESULTS: The majority of the respondents did not know about pregnancy-related deep vein thrombosis (DVT) (80.8%) and pulmonary embolism (PE) (88.9). Predictors of DVT knowledge levels include husbands' level of education (at most secondary education) (AOR = 4.2; 95%CI = 2.554-6.816; p = <0.001) and maternal age (AOR = 0.9; 95% CI = 0.930-0.999; p = 0.044) while predictors of PE knowledge level include husbands' level of education (at most secondary education) (AOR = 2.1; 95%CI = 1.005-4.436; p = 0.048) and maternal occupation (professionals) (AOR = 0.4; 95% CI = 0.219- 0.794; p = 0.008). CONCLUSION: Pregnant women are unaware of pregnancy-related VTE in Enugu, Nigeria. Immediate designing and implementation of the 'Move for Flow' program are recommended to improve maternal knowledge levels of VTE.

CONTEXTE: La grossesse est un facteur de risque important pour la thromboembolie veineuse (TEV), qui entraîne des taux élevés de morbidité et de mortalité maternelles et périnatales. La sensibilisation est l'une des stratégies de prévention de la TEV. À cet effet, nous avons conçu le programme "Move for Flow", qui vise à éduquer les mères sur la TEV, ses symptômes et les stratégies de prévention.Pour une mise en œuvre optimale de ce programme, le niveau de connaissance actuel de la population concernée est d'un grand intérêt pour guider la conception et la mise en œuvre du programme. OBJECTIF: Évaluer le niveau de connaissance de la TEV chez les femmes enceintes nigérianes. MÉTHODOLOGIE: Dans cette enquête transversale, 1000 femmesenceintes résidant à Enugu, au Nigeria, ont rempli un questionnaire structuré qui évaluait leurs connaissances sur la TEV, ses facteurs de risque et les stratégies de prévention. D'un point de vue quantitatif, leurs connaissances ont été classées en trois catégories : pas de connaissance, faible connaissance, connaissance moyenne et bonne connaissance. RÉSULTATS: La majorité des personnes interrogées ne connaissaient pas la thrombose veineuse profonde (TVP) (80,8 %) et l'embolie pulmonaire (EP) liées à la grossesse (88,9 %). Les facteurs prédictifs des niveaux de connaissance de la TVP comprennent le niveau d'éducation du mari (au plus l'éducation secondaire) (AOR=4,2 ; 95% CI =2,554-6,816 ; p= <0,001) et l'âge de la mère (AOR=0,9 ; 95% CI=0,930-0,999 ; p=0. 044) tandis que les prédicteurs du niveau de connaissance de l'EP incluent le niveau d'éducation du mari (auplus l'éducation secondaire) (AOR=2.1 ; 95%CI=1.005-4.436 ; p=0.048) et la profession de la mère (professionnels) (AOR=0.4 ; 95% CI=0.219-0.794 ; p=0.008). CONCLUSION: Les femmes enceintes ne sont pas conscientes de la TEV liée à la grossesse à Enugu, au Nigeria. La conception et la mise en œuvre immédiates du programme " Move for Flow " sont recommandées pour améliorer les connaissances maternelles sur la. Mots clés: Grossesse, Thromboembolie veineuse, Thrombose veineuse profonde, Embolie pulmonaire, Nigeria.

Cardiac arrest during hyperacute caesarean section due to peripartum cardiomyopathy.

Peripartum cardiomyopathy is a rare and potentially dangerous form of heart failure presenting in women in the last month of pregnancy until five months post partum. The pathogenesis is believed to be multifactorial. This case report describes a young woman with adiposity and preeclampsia who was admitted to hospital and whose clinical condition quickly deteriorated. During the emergency caesarian section, the woman suffered a cardiac arrest and was successfully resuscitated. Echocardiography showed heart failure with an ejection fraction less-than 45% confirming the diagnosis of peripartum cardiomyopathy.

Evaluation of obstetric outcomes in Brazilian pregnant women with Takayasu arteritis.

OBJECTIVE: Takayasu arteritis (TAK) is a rare chronic granulomatous vasculitis that affects large vessels and usually begins in women of childbearing age, so it is not uncommon for pregnancies to occur in these patients. However, there is limited information about these pregnancies, with reports of adverse maternal and obstetric outcomes. The objective of this study is to evaluate adverse maternal, fetal and neonatal events in pregnant patients with TA. METHODS: This is a cross-sectional study with retrospective data collection. We reviewed 22 pregnancies in 18 patients with TAK, according to the American College of Rheumatology criteria, that were followed up in a high-risk prenatal clinic specialized in systemic autoimmune diseases and thrombophilia (PrAT) at Hospital Universitário Pedro Ernesto, from 1998 to 2021. RESULTS: In twenty-two pregnancies, the mean age of patients was 28.09 years and the mean duration disease was 10.9 years. Of the 18 patients with TAK studied, only one had the diagnosis during pregnancy and had active disease. All other patients had a previous diagnosis of TAK and only 3 had disease activity during pregnancy. Twelve patients (66.6%) had previous systemic arterial hypertension and eleven (61.1%) had renal involvement. Among maternal complications, eight patients (36.3%) developed preeclampsia and six (27.2%) had uncontrolled blood pressure without proteinuria, while 10 (45%) had puerperal complications. Four (18.1%) births were premature, all due to severe preeclampsia and eight newborns (34.7%) were small for gestational age. When all maternal and fetal/neonatal outcomes included in this study were considered, only 6 (27.2%) pregnancies were uneventful. CONCLUSION: Although there were no maternal deaths or pregnancy losses in this study, the number of adverse events was considerably high. Hypertensive disorders and small for gestational age newborns were more common than general population, while the number of patients with active disease was low. These findings suggest that pregnancies in patients with TAK still have several complications and a high-risk prenatal care and delivery are necessary for these patients.

Peripartum Cardiomyopathy: Current Understanding of Pathophysiology, Diagnostic Workup, Management, and Outcomes.

Peripartum cardiomyopathy (PPCM) is a relatively rare, potentially life-threatening, idiopathic form of cardiomyopathy that affects previously healthy young women during late pregnancy or in the early postpartum period and is characterized by left ventricular systolic dysfunction in the absence of any other identifiable cardiac causes. Morbidity and mortality with PPCM are remarkably high and it continues to be one of the leading causes of maternal death. Although remarkable advances have been made in our understanding of PPCM in the last few decades, unanswered questions remain regarding its pathophysiology, diagnostic workup, and management options. In this article, we will complete an updated, comprehensive review of PPCM, including the epidemiology and risk factors, proposed etiology, presentation and complications, management, prognostic indicators and outcomes. In addition, we will identify current challenges and gaps in knowledge.

Perimortem caesarean section in COVID-19 era.

Cardiac arrest in pregnancy is very rare. Various methods have been proposed to return spontaneous circulation and prevent mortality, such as Perimortem Caesarean Section (PMCS). Since 2019, the COVID-19 pandemic has added to the difficulty in decision making and performing PMCS. Infection prevention being a priority due to the rapid spreading of the virus could cause hesitation upon initiating an emergency procedure, especially PMCS. We have reviewed the issues impacting on basic and advanced life support in adults with suspected or confirmed COVID-19.

Eventos aórticos en el embarazo de pacientes con síndrome de Marfan. Lecciones de un estudio multicéntrico / Aortic events in pregnant patients with Marfan syndrome. Lessons from a multicenter study

Introducción y objetivos: El embarazo en el síndrome de Marfan (SM) incrementa el riesgo de eventos aórticos. La evidencia clínica actual es escasa y no existe un consenso específico sobre el tratamiento óptimo de estas pacientes. Se presenta nuestra experiencia multicéntrica. Métodos: Entre enero de 2004 y enero de 2020, 632 pacientes con SM mantuvieron revisiones periódicas en unidades de Marfan. Durante este periodo se identificó a todas las mujeres gestantes y se analizó la incidencia de eventos aórticos durante el embarazo y el puerperio. Resultados: Se hallaron 133 embarazos de 89 mujeres (8 con cirugía de aorta previa). No hubo mortalidad materna. Cinco mujeres sufrieron eventos aórticos durante el tercer trimestre del embarazo y el puerperio (2 disecciones tipo A, 1 disección tipo B y 2 crecimientos significativos de la aorta (≥ 3 mm). La incidencia de eventos aórticos fue del 3,7%. Se evidenció una mayor tendencia a eventos con diámetros aórticos pregestacionales ≥ 40 mm (p=0,058). La mortalidad fetal fue del 3%. El 37,6% de los partos se realizaron mediante cesárea. Conclusiones: Las mujeres con SM tienen un incremento del riesgo de eventos aórticos en el embarazo, especialmente durante el tercer trimestre y el periodo posparto. Se debería valorar, en centros de referencia, la cirugía aórtica profiláctica pregestacional con diámetros aórticos ≥ 40 mm. Es importante un diagnóstico precoz, un estudio pregestacional de toda la aorta, la administración de bloqueadores beta y un estrecho seguimiento durante el embarazo, especialmente durante el último trimestre y el posparto (AU)

Introduction and objectives: Pregnancy in women with Marfan syndrome (MS) is associated with an increased risk of aortic events. The clinical evidence on pregnant patients with MS is limited and there is no specific consensus on their optimal management. We report our multicenter experience. Methods: From January 2004 to January 2020, 632 patients with MS underwent periodic monitoring in Marfan units. During this period, we identified all pregnant women with MS and analyzed the incidence of aortic events during pregnancy and puerperium. Results: There were 133 pregnancies in 89 women with MS (8 women with prior aortic surgery). There were no maternal deaths, but 5 women had aortic events during the third trimester and puerperium (type A dissections in 2, type B dissection in 1, and significant [≥ 3mm] aortic growth in 2). The aortic event rate was 3.7%. Pregestational aortic diameter≥ 40 mm showed a nonsignificant association with aortic events (P=.058). Fetal mortality was 3% and 37.6% of births were cesarean deliveries. Conclusions: Women with MS have an increased risk of aortic events during pregnancy, especially in the third trimester and postpartum period. Patients with MS and aortic diameters ≥40mm should be assessed in experienced centers for prophylactic aortic surgery before pregnancy. It is important to provide early diagnosis, prepregnancy study of the aorta, beta-blocker administration, and close monitoring during pregnancy, especially during the last trimester and postpartum (AU)

Early Recognition and Treatment for the Optimal Care of Individuals With Peripartum Cardiomyopathy.

Peripartum cardiomyopathy (PPCM) is a life-threatening pregnancy-associated condition that often develops within the last month of pregnancy and up to 5 months postpartum. Although it is uncommon, the incidence in the United States is on the rise, especially among Black individuals. Early recognition and treatment are crucial for long-term health and the recovery of left ventricular ejection fraction. Most people with PPCM will recover with time, but a multidisciplinary team is needed to help with long-term treatment. Informed contraception counseling is also needed to minimize the incidence of subsequent pregnancy before recovery, which could worsen conditions. The purpose of this article is to review PPCM and discuss early recognition and management options, which may minimize complications and improve outcomes.

Management of mechanical aortic valve thrombosis during the first trimester of pregnancy.

BACKGROUND: Cardiovascular diseases are the leading cause of morbidity and mortality in pregnant women. On the other hand, cardiac surgery is not so common for pregnant women. CASE REPORT: We present the case of a pregnant woman with diagnosed thrombosis of the mechanical aortic valve in the 12th gestational week. The patient underwent surgery, and successfully completed her pregnancy till the 37th gestational week. CONCLUSION: We showed that, despite general anaesthesia during the first trimester of pregnancy, the application of the nonpulsatile flow of extracorporeal circulation and mild hypothermia, the operation was successfully completed and that both mother and fetus survived.

Aortopathy in pregnancy.

Aortic dissection is one of the most common causes of death in pregnancy. Most cases are caused by hereditary thoracic aortopathy (HTA), and women are often unaware they are at risk. Awareness, early recognition and involvement of senior clinicians from the expert cardio-obstetric team are essential to facilitate early diagnosis and carefully planned and coordinated antenatal and postnatal care. Frequent imaging antenatally and good blood pressure control are key. Delivery needs particular attention with optimal pain control and techniques to minimise maternal effort. Dissection is most common post partum and a period of close surveillance with meticulous blood pressure control after delivery is crucial, as well as follow-up of the baby in paediatric services. All women with a family history of aortic dissection or sudden death should be investigated. Women with known HTA should be offered specialist individualised pre-pregnancy counselling, including advice about genetics and inheritance, before starting a family. Future research is directed towards more individualised risk assessment, pre-pregnancy advice and pharmacological options to reduce dissection risk.

Trends in Venous Thromboembolism and Associated Risk Factors During Delivery Hospitalizations From 2000 to 2018.

OBJECTIVE: To characterize trends in and risk factors for venous thromboembolism (VTE) during delivery hospitalizations in the United States. METHODS: The 2000-2018 National Inpatient Sample was used for this repeated cross-sectional analysis. Venous thromboembolism (including deep vein thrombosis [DVT] and pulmonary embolism) during delivery hospitalizations for women aged 15 to 54 years was determined by year. Temporal trends in VTE were characterized using joinpoint regression with estimates presented as the average annual percent change. Temporal trends in common VTE risk factors were also analyzed. The proportion of vaginal and cesarean deliveries by year that had VTE risk factors was determined, and average annual percent changes with 95% CIs were calculated. The relationship between risk factors and the likelihood of VTE events was determined with adjusted and unadjusted logistic regression models. RESULTS: Of 73,109,789 delivery hospitalizations, 48,546 VTE events occurred (6.6/10,000 deliveries), including 37,312 DVT diagnoses and 12,487 pulmonary embolism diagnoses. Rates increased significantly for vaginal (average annual percent change 2.5%, 95% CI 1.5-3.5%) but not for cesarean delivery hospitalizations (average annual percent change 0.3%, 95% CI -1.0 to 1.6%) over the study period. Pulmonary embolism increased for both vaginal delivery (average annual percent change 8.7%, 95% CI 6.0-11.5%) and cesarean delivery (average annual percent change 4.9%, 95% CI 3.6-6.2%). The proportion of cesarean deliveries with at least one VTE risk factor increased from 27.2% in 2000 to 43.6% in 2018 (average annual percent change 2.6%, 95% CI 2.2-3.1%) and for vaginal deliveries, from 17.7% to 31.4% (average annual percent change 3.4%, 95% CI 2.3-4.4%). The 5.9% of deliveries with at least two VTE risk factor diagnoses accounted for 25.4% of VTE diagnoses. Factors with the highest VTE risk included transfusion (adjusted odds ratio [aOR] 4.1, 95% CI 3.7-4.5), infection (aOR 5.8, 95% CI 5.3-6.3), history of VTE (aOR 7.2, 95% CI 6.2-8.4), and thrombophilias (aOR 9.6, 95% CI 8.5-11.0). CONCLUSION: Both risk factors for VTE and rate of pulmonary embolism increased over the study period. Deep vein thrombosis increased during vaginal delivery hospitalizations but not during cesarean delivery hospitalizations.

Proposed Management Policy for Pregnant Women with Loeys-Dietz Syndrome Following Prophylactic Aortic Root Replacement Based on Experience from a Tertiary Care Center.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder with a high incidence of aortic dissection (AD). After treating two previously reported cases of postpartum AD in women with LDS following prophylactic aortic root replacement (ARR), we succeeded in managing a 30-year-old primigravida with no AD during her peripartum period. On the basis of the patient's stated desire to conceive during preconception counseling, a multidisciplinary team was assembled. She conceived naturally after receiving prophylactic ARR and beta-blocker treatment. Multidisciplinary patient care included precise blood pressure management, continuation of beta-blocker treatment, cardiovascular assessment with echocardiogram, regional anesthesia during labor, prevention of lactation, and resumption of angiotensin II receptor blocker therapy immediately after delivery. On the basis of our assessment of three cases, including this case, and a literature review, we propose a peripartum management strategy for patients with LDS following prophylactic ARR.

Differences in the prevention and incidence of maternal venous thromboembolism according to the type of institution in Japan in 2018: A sub-analysis of national questionnaire surveillance.

AIM: To clarify the relation between institutions capacity to manage venous thromboembolism (VTE) and its incidence in pregnant women throughout Japan. METHODS: Among the 2299 institutions that received the surveillance questionnaire, 666 (29.0%) responded, after which data from 295 961 women who gave birth at those institutions in 2018 were analyzed. Incidences and characteristics of antepartum and postpartum VTE in perinatal medical centers (PMCs), general hospital with obstetric facilities (GHs), and maternal clinic with beds (MCs) were then determined. RESULTS: The frequencies at which routine antepartum and postpartum thromboprophylaxis for high-risk women and routine transport to the more advanced medical institutions upon antepartum and postpartum pulmonary thromboembolism (PE) onset were performed differed significantly according to types of institution (PMCs: 92.4%, 96.2%, 23.8%, and 21.2%; GHs: 76.5%, 80.6%, 58.8%, and 54.1%; MCs: 29.2%, 41.7%, 96.5%, and 96.2%, respectively). Among the 295 961 women analyzed, 243 (0.082%) developed VTE. Incidences of antepartum VTE differed significantly according to institution types (PMCs: 106.4, GHs: 51.6, and MCs: 11.6 per 100 000 women). PMCs and GHs had significantly higher incidences of postpartum VTE compared to MCs (43.3 and 26.6 vs. 10.7 per 100 000 women, respectively), although PMCs and GHs had similar incidences. Among the four women (1.4%) who died due to VTE, three and one developed a PE in a PMC and MC, respectively. CONCLUSIONS: PMCs had higher incidences of VTE despite their more frequent performance of thromboprophylaxis. Several pregnant women with higher risk of VTE transported to PMCs.